TY  - CONF
AU  - Mihajlović, Dragana R.
AU  - Rakin, Marko P.
AU  - Međo, Bojan I.
AU  - Đokić, Veljko R.
PY  - 2024
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7382
PB  - Vancouver : Peers Alley Media
C3  - 6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024
T1  - Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application
EP  - 40
SP  - 39
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7382
ER  - 

@conference{
author = "Mihajlović, Dragana R. and Rakin, Marko P. and Međo, Bojan I. and Đokić, Veljko R.",
year = "2024",
publisher = "Vancouver : Peers Alley Media",
journal = "6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024",
title = "Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application",
pages = "40-39",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7382"
}

Mihajlović, D. R., Rakin, M. P., Međo, B. I.,& Đokić, V. R.. (2024). Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application. in 6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024
Vancouver : Peers Alley Media., 39-40.
https://hdl.handle.net/21.15107/rcub_technorep_7382

Mihajlović DR, Rakin MP, Međo BI, Đokić VR. Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application. in 6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024. 2024;:39-40.
https://hdl.handle.net/21.15107/rcub_technorep_7382 .

Mihajlović, Dragana R., Rakin, Marko P., Međo, Bojan I., Đokić, Veljko R., "Microstructure, mechanical and corrosion properties of anodized ultrafine-grained titanium based materials for medical application" in 6th edition of Advanced Materials Science World Congress, Adv. Materials Science 2024, March 21-22, 2024 (2024):39-40,
https://hdl.handle.net/21.15107/rcub_technorep_7382 .

TY  - CHAP
AU  - Mihajlović, Dragana
AU  - Rakin, Marko
AU  - Hohenwarter, Anton
AU  - Veljović, Đorđe
AU  - Kojić, Vesna
AU  - Đokić, Veljko
PY  - 2024
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7147
AB  - Primary implant stability after implantation is in relation with its good mechanical contact with the touching tissue. Adequate integration of the implant with the bone tissue is necessary to provide safety and efficiency of the implant over its life. Generally, two surface properties are the most important facts for tissue response to the implant: the surface topography and chemical composition. Compared to a smooth implant surface, a controlled rough surface provides more surface area for integration with the surrounding tissues and allows successful implant ingrowth into the tissues. It was found that the nanostructured modification of the titanium surface on the level of nano-sized pores influences the adhesion, spreading and growing of osteoblastic cells. There are many methods for nanostructure modification of biomedical alloy surfaces, but one of the common techniques is electrochemical anodization (anodic oxidation). Electrochemical anodization is a method that leads to the creation of a nanotubular oxide film on the material surface. The advantage of anodic oxidation is the possibility of controlling the nanostructured morphology of the surface and dimensions of nanotubes, such as diameter, length, wall thickness and shape of nanotubes through variation of the solution, pH value, potential or duration of anodic oxidation. 
Surface modification of Ti-13Nb-13Zr alloy in a coarse-grained (as received) and ultrafine-grained state induced by high pressure torsion was conducted using an electrochemical anodization process in a 1 M H3PO4 + NaF electrolyte, for 30, 60, 90 and 120 minutes. Scanning electron microscopy (SEM) was used to analyze the morphology, while atomic force microscopy (AFM) was used to characterize the topography of the modified surface. The results showed that a homogenous nanotubular oxide film consisting of nanotubes could be obtained using the electrochemical anodization treatment, while the roughness of the nanostructured surface increased compared to the bare surface. The aim of the studies given in this chapter is to examine the morphology of the nanostructured surface and estimate in vitro biocompatibility of the above-mentioned titanium alloy after the creation of the nanotubular oxide film. In vitro examinations were performed on mouse fibroblast (L929) and human fibroblast (MRC-5) cell lines. The results showed that the nanotubular oxide film obtained on the coarse-grained Ti-13Nb-13Zr alloy (CG TNZ) and the ultrafine-grained Ti-13Nb-13Zr alloy (UFG TNZ) increased the fractions of surviving cells compared to their counterpart alloy, while the cells had better spreading and adhesion on the nanostructured and bare surfaces of the UFG titanium alloy.
PB  - Hoboken : John Wiley & Sons
PB  - Beverly : Scrivener Publishing LLC
T2  - Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics
T1  - The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application
EP  - 150
SP  - 121
DO  - 10.1002/9781394175109.ch5
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7147
ER  - 

@inbook{
author = "Mihajlović, Dragana and Rakin, Marko and Hohenwarter, Anton and Veljović, Đorđe and Kojić, Vesna and Đokić, Veljko",
year = "2024",
abstract = "Primary implant stability after implantation is in relation with its good mechanical contact with the touching tissue. Adequate integration of the implant with the bone tissue is necessary to provide safety and efficiency of the implant over its life. Generally, two surface properties are the most important facts for tissue response to the implant: the surface topography and chemical composition. Compared to a smooth implant surface, a controlled rough surface provides more surface area for integration with the surrounding tissues and allows successful implant ingrowth into the tissues. It was found that the nanostructured modification of the titanium surface on the level of nano-sized pores influences the adhesion, spreading and growing of osteoblastic cells. There are many methods for nanostructure modification of biomedical alloy surfaces, but one of the common techniques is electrochemical anodization (anodic oxidation). Electrochemical anodization is a method that leads to the creation of a nanotubular oxide film on the material surface. The advantage of anodic oxidation is the possibility of controlling the nanostructured morphology of the surface and dimensions of nanotubes, such as diameter, length, wall thickness and shape of nanotubes through variation of the solution, pH value, potential or duration of anodic oxidation. 
Surface modification of Ti-13Nb-13Zr alloy in a coarse-grained (as received) and ultrafine-grained state induced by high pressure torsion was conducted using an electrochemical anodization process in a 1 M H3PO4 + NaF electrolyte, for 30, 60, 90 and 120 minutes. Scanning electron microscopy (SEM) was used to analyze the morphology, while atomic force microscopy (AFM) was used to characterize the topography of the modified surface. The results showed that a homogenous nanotubular oxide film consisting of nanotubes could be obtained using the electrochemical anodization treatment, while the roughness of the nanostructured surface increased compared to the bare surface. The aim of the studies given in this chapter is to examine the morphology of the nanostructured surface and estimate in vitro biocompatibility of the above-mentioned titanium alloy after the creation of the nanotubular oxide film. In vitro examinations were performed on mouse fibroblast (L929) and human fibroblast (MRC-5) cell lines. The results showed that the nanotubular oxide film obtained on the coarse-grained Ti-13Nb-13Zr alloy (CG TNZ) and the ultrafine-grained Ti-13Nb-13Zr alloy (UFG TNZ) increased the fractions of surviving cells compared to their counterpart alloy, while the cells had better spreading and adhesion on the nanostructured and bare surfaces of the UFG titanium alloy.",
publisher = "Hoboken : John Wiley & Sons, Beverly : Scrivener Publishing LLC",
journal = "Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics",
booktitle = "The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application",
pages = "150-121",
doi = "10.1002/9781394175109.ch5",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7147"
}

Mihajlović, D., Rakin, M., Hohenwarter, A., Veljović, Đ., Kojić, V.,& Đokić, V.. (2024). The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application. in Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics
Hoboken : John Wiley & Sons., 121-150.
https://doi.org/10.1002/9781394175109.ch5
https://hdl.handle.net/21.15107/rcub_technorep_7147

Mihajlović D, Rakin M, Hohenwarter A, Veljović Đ, Kojić V, Đokić V. The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application. in Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics. 2024;:121-150.
doi:10.1002/9781394175109.ch5
https://hdl.handle.net/21.15107/rcub_technorep_7147 .

Mihajlović, Dragana, Rakin, Marko, Hohenwarter, Anton, Veljović, Đorđe, Kojić, Vesna, Đokić, Veljko, "The Effect of the Nanostructured Surface Modification on the Morphology and Biocompatibility of Ultrafine-Grained Titanium Alloy for Medical Application" in Mechanical Engineering in Biomedical Application: Bio-3D Printing, Biofluid Mechanics, Implant Design, Biomaterials, Computational Biomechanics, Tissue Mechanics (2024):121-150,
https://doi.org/10.1002/9781394175109.ch5 .,
https://hdl.handle.net/21.15107/rcub_technorep_7147 .

TY  - CONF
AU  - Rakin, Marko
AU  - Mihajlović, Dragana
AU  - Međo, Bojan
AU  - Đokić, Veljko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6294
AB  - The Ti-13Nb-13Zr alloy made by conventional methods (coarse-grained, CG) was examined, as well as the alloy and commercially pure titanium (cpTi) after the high pressure torsion (HPT) process (ultrafine-grained, UFG) performed at room temperature. All materials were subjected to nanostructured surface modification. Nanostructured surface modification was done in 1M H3PO4 + 0.5 wt. % NaF electrolyte during 60 and 90 minutes, for the desired potential of 25V with a scan rate of 100 mVs-1. As the result of the nanostructured surface modification nanotubular titanium based oxide layer was obtained.
Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the homogeneity of nanotubular titanium based oxide layer and dimensions of the formed nanotubes. In order to define the chemical structure of oxide layer, energy dispersive spectroscopy (EDS) was used. The obtained results indicate that the duration of the nanostructured surface modification significantly affects on the homogeneity of the nanotubular titanium based oxide layer morphology, as well as on the dimensions of the nanotubes (diameter and wall thickness of the nanotubes). Also, the effect of the HPT process on the homogeneity and thickness of the nanotubular oxide layer (length of the nanotubes) are shown and discussed.
The mechanical behavior of nanotubular titanium based oxide layer was examined by nanoindentation test. The control of nanoindentation test was done by total displacement. The displacements were 2000 nm for non-modified surface and 10% of the thickness of nanotubular titanium based oxide layer for modified surface. The test was performed on a nanoindenter using as an indenter the Berkovich-type diamond tip. As results, loading-displacement curves and the mean value of ten measurements of the surface modulus of elasticity and nanohardness were obtained. Also, in order to characterize deformation of the oxide layer after nanoindentation SEM was done. Having in mind that nanotubular oxide thin layer can affect tensile properties of metallic materials, tensile testing was performed.
PB  - InovSciTech No. 302, Uttarahalli, Bangalore-560061, India
C3  - 6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference
T1  - Structural and mechanical behavior of titanium based oxide thin layer for biomedical application
EP  - 15
SP  - 14
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6294
ER  - 

@conference{
author = "Rakin, Marko and Mihajlović, Dragana and Međo, Bojan and Đokić, Veljko",
year = "2023",
abstract = "The Ti-13Nb-13Zr alloy made by conventional methods (coarse-grained, CG) was examined, as well as the alloy and commercially pure titanium (cpTi) after the high pressure torsion (HPT) process (ultrafine-grained, UFG) performed at room temperature. All materials were subjected to nanostructured surface modification. Nanostructured surface modification was done in 1M H3PO4 + 0.5 wt. % NaF electrolyte during 60 and 90 minutes, for the desired potential of 25V with a scan rate of 100 mVs-1. As the result of the nanostructured surface modification nanotubular titanium based oxide layer was obtained.
Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were used to characterize the homogeneity of nanotubular titanium based oxide layer and dimensions of the formed nanotubes. In order to define the chemical structure of oxide layer, energy dispersive spectroscopy (EDS) was used. The obtained results indicate that the duration of the nanostructured surface modification significantly affects on the homogeneity of the nanotubular titanium based oxide layer morphology, as well as on the dimensions of the nanotubes (diameter and wall thickness of the nanotubes). Also, the effect of the HPT process on the homogeneity and thickness of the nanotubular oxide layer (length of the nanotubes) are shown and discussed.
The mechanical behavior of nanotubular titanium based oxide layer was examined by nanoindentation test. The control of nanoindentation test was done by total displacement. The displacements were 2000 nm for non-modified surface and 10% of the thickness of nanotubular titanium based oxide layer for modified surface. The test was performed on a nanoindenter using as an indenter the Berkovich-type diamond tip. As results, loading-displacement curves and the mean value of ten measurements of the surface modulus of elasticity and nanohardness were obtained. Also, in order to characterize deformation of the oxide layer after nanoindentation SEM was done. Having in mind that nanotubular oxide thin layer can affect tensile properties of metallic materials, tensile testing was performed.",
publisher = "InovSciTech No. 302, Uttarahalli, Bangalore-560061, India",
journal = "6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference",
title = "Structural and mechanical behavior of titanium based oxide thin layer for biomedical application",
pages = "15-14",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6294"
}

Rakin, M., Mihajlović, D., Međo, B.,& Đokić, V.. (2023). Structural and mechanical behavior of titanium based oxide thin layer for biomedical application. in 6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference
InovSciTech No. 302, Uttarahalli, Bangalore-560061, India., 14-15.
https://hdl.handle.net/21.15107/rcub_technorep_6294

Rakin M, Mihajlović D, Međo B, Đokić V. Structural and mechanical behavior of titanium based oxide thin layer for biomedical application. in 6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference. 2023;:14-15.
https://hdl.handle.net/21.15107/rcub_technorep_6294 .

Rakin, Marko, Mihajlović, Dragana, Međo, Bojan, Đokić, Veljko, "Structural and mechanical behavior of titanium based oxide thin layer for biomedical application" in 6th Global Webinar on Materials Science & Engineering (GWMSE-2023), The International Research Conference (2023):14-15,
https://hdl.handle.net/21.15107/rcub_technorep_6294 .

TY  - CONF
AU  - Mihajlović, Dragana
AU  - Rakin, Marko
AU  - Veljović, Đorđe
AU  - Međo, Bojan
AU  - Đokić, Veljko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7011
AB  - The coarse-grained (CG) and ultrafine-grained (UFG) Ti-13Nb-13Zr alloy (TNZ) were used as tested materials in this
study. UFG alloy was obtained using a high-pressure torsion process (HPT) at room temperature, with 5 rotations, and
with 4.1 GPa pressure. After that, the surface was modified using electrochemical anodization in the 1M H3PO4 + NaF
electrolyte, for 60 and 90 minutes.
Scanning electron microscopy (SEM) was used to characterize the morphology of the modified surface after
electrochemical anodization. In order to determine whether the electrochemical anodization leads to obtaining the
surface modulus of elasticity values close to the values characteristic of the human bones, a nanoindentation test was
done. The nanoindentation test was performed on the device called nanoindenter G200, Agilent Technologies, where
a diamond tip of the Berkovich type shaped as a three-sided pyramid was used as an indenter. Control of
the nanoindentation test was done by nanoindentation depth, where for non-anodized materials a depth of 2000 nm was
used, while for anodized materials a minimum value of 10% of the thickness of the formed nanostructured oxide layer
was used. Biocompatibility of the tested titanium alloy was estimated by the tetrazolium salt colorimetric test
(MTT test) using mouse fibroblasts (L-929) and human lung fibroblasts (MRC-5). The cell adhesion on the alloy
surface was analyzed using SEM.
Electrochemical anodization has led to the formation of the nanostructured oxide layer on the titanium alloy surface.
The obtained results show the existence of the influence of anodizing time on the nanostructured oxide layer
morphology. Characterization of the titanium alloy surface using nanoindentation showed a decrease in the values
of modulus of elasticity for an alloy with a nanostructured oxide layer, which is close to the values of bone tissue in
the human body. The results of the MTT test showed that the titanium alloys before and after electrochemical
anodization were not cytotoxic. After electrochemical anodization, a uniform nanostructured surface, with nanotubes,
was formed which led to better cell viability and adhesion of L-929 and MRC-5 cells in contact with the test alloys than
of cells in contact with the control material.
PB  - Belgrade : Association of Metallurgical Engineers of Serbia (AMES)
C3  - Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023
T1  - Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization
SP  - 56
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7011
ER  - 

@conference{
author = "Mihajlović, Dragana and Rakin, Marko and Veljović, Đorđe and Međo, Bojan and Đokić, Veljko",
year = "2023",
abstract = "The coarse-grained (CG) and ultrafine-grained (UFG) Ti-13Nb-13Zr alloy (TNZ) were used as tested materials in this
study. UFG alloy was obtained using a high-pressure torsion process (HPT) at room temperature, with 5 rotations, and
with 4.1 GPa pressure. After that, the surface was modified using electrochemical anodization in the 1M H3PO4 + NaF
electrolyte, for 60 and 90 minutes.
Scanning electron microscopy (SEM) was used to characterize the morphology of the modified surface after
electrochemical anodization. In order to determine whether the electrochemical anodization leads to obtaining the
surface modulus of elasticity values close to the values characteristic of the human bones, a nanoindentation test was
done. The nanoindentation test was performed on the device called nanoindenter G200, Agilent Technologies, where
a diamond tip of the Berkovich type shaped as a three-sided pyramid was used as an indenter. Control of
the nanoindentation test was done by nanoindentation depth, where for non-anodized materials a depth of 2000 nm was
used, while for anodized materials a minimum value of 10% of the thickness of the formed nanostructured oxide layer
was used. Biocompatibility of the tested titanium alloy was estimated by the tetrazolium salt colorimetric test
(MTT test) using mouse fibroblasts (L-929) and human lung fibroblasts (MRC-5). The cell adhesion on the alloy
surface was analyzed using SEM.
Electrochemical anodization has led to the formation of the nanostructured oxide layer on the titanium alloy surface.
The obtained results show the existence of the influence of anodizing time on the nanostructured oxide layer
morphology. Characterization of the titanium alloy surface using nanoindentation showed a decrease in the values
of modulus of elasticity for an alloy with a nanostructured oxide layer, which is close to the values of bone tissue in
the human body. The results of the MTT test showed that the titanium alloys before and after electrochemical
anodization were not cytotoxic. After electrochemical anodization, a uniform nanostructured surface, with nanotubes,
was formed which led to better cell viability and adhesion of L-929 and MRC-5 cells in contact with the test alloys than
of cells in contact with the control material.",
publisher = "Belgrade : Association of Metallurgical Engineers of Serbia (AMES)",
journal = "Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023",
title = "Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization",
pages = "56",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7011"
}

Mihajlović, D., Rakin, M., Veljović, Đ., Međo, B.,& Đokić, V.. (2023). Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization. in Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023
Belgrade : Association of Metallurgical Engineers of Serbia (AMES)., 56.
https://hdl.handle.net/21.15107/rcub_technorep_7011

Mihajlović D, Rakin M, Veljović Đ, Međo B, Đokić V. Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization. in Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023. 2023;:56.
https://hdl.handle.net/21.15107/rcub_technorep_7011 .

Mihajlović, Dragana, Rakin, Marko, Veljović, Đorđe, Međo, Bojan, Đokić, Veljko, "Advancement of biocompatibility and mechanical surface characteristics of the Ti-13Nb-13Zr alloy using electrochemical anodization" in Book of Abstracts / 5th Metallurgical & Materials Engineering Congress of SouthEast Europe MME SEE Congress 2023, Trebinje, Bosnia and Herzegovina 7-10th June 2023 (2023):56,
https://hdl.handle.net/21.15107/rcub_technorep_7011 .

TY  - JOUR
AU  - Mihajlović, Dragana
AU  - Rakin, Marko
AU  - Bajat, Jelena
AU  - Đokić, Veljko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6975
AB  - Nanostructured surface modification was performed on the ultrafine-grained commercially
pure titanium (UFG cpTi) using electrochemical anodization. The characterization of the
morphology of the nanostructured surface obtained during different times of electrochemical
anodization was done using scanning electron microscopy (SEM). The corrosion resistance
of the materials was examined using the potentiodynamic method and electrochemical
impedance spectroscopy (EIS), during which the electrochemical characteristics of oxide
layers and the evaluation of the corrosion resistance of the mentioned materials were
determined. These materials were exposed to a solution simulating conditions in the human
body (artificial saliva solution) with a pH of 5.5 at a temperature of 37 ºC. The obtained results
indicate the extensive influence of time, as a parameter of electrochemical anodization on the
surface morphology. The electrochemical anodization of 60 minutes can lead to the creation
of the nanotubular oxide layer on the UFG cpTi surface, while the electrochemical anodization
of 30 and 90 minutes did not lead to the creation of the nanotubular oxide layer, but it is up
to the surface modification of UFG cpTi. Electrochemical tests showed a slight increase in the
corrosion resistance in a solution of artificial saliva after electrochemical anodization. Also,
the electrochemical impedance spectra for anodized and non-anodized UFG cpTi show the
characteristics of corrosion resistance, but the anodized UFG cpTi has better resistance to the
oxide layer. It can be concluded that anodized UFG cpTi has better corrosion stability, but
both non-anodized and anodized UFG cpTi show exceptional corrosion stability in simulated
conditions of the human body, which makes them equally suitable for use in medicine.
PB  - Association of Metallurgical Engineers of Serbia
T2  - Metallurgical and Materials Data. Advanced Functional Materials
T1  - Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution
EP  - 11
IS  - 1
SP  - 7
VL  - 1
DO  - 10.56801/MMD3
ER  - 

@article{
author = "Mihajlović, Dragana and Rakin, Marko and Bajat, Jelena and Đokić, Veljko",
year = "2023",
abstract = "Nanostructured surface modification was performed on the ultrafine-grained commercially
pure titanium (UFG cpTi) using electrochemical anodization. The characterization of the
morphology of the nanostructured surface obtained during different times of electrochemical
anodization was done using scanning electron microscopy (SEM). The corrosion resistance
of the materials was examined using the potentiodynamic method and electrochemical
impedance spectroscopy (EIS), during which the electrochemical characteristics of oxide
layers and the evaluation of the corrosion resistance of the mentioned materials were
determined. These materials were exposed to a solution simulating conditions in the human
body (artificial saliva solution) with a pH of 5.5 at a temperature of 37 ºC. The obtained results
indicate the extensive influence of time, as a parameter of electrochemical anodization on the
surface morphology. The electrochemical anodization of 60 minutes can lead to the creation
of the nanotubular oxide layer on the UFG cpTi surface, while the electrochemical anodization
of 30 and 90 minutes did not lead to the creation of the nanotubular oxide layer, but it is up
to the surface modification of UFG cpTi. Electrochemical tests showed a slight increase in the
corrosion resistance in a solution of artificial saliva after electrochemical anodization. Also,
the electrochemical impedance spectra for anodized and non-anodized UFG cpTi show the
characteristics of corrosion resistance, but the anodized UFG cpTi has better resistance to the
oxide layer. It can be concluded that anodized UFG cpTi has better corrosion stability, but
both non-anodized and anodized UFG cpTi show exceptional corrosion stability in simulated
conditions of the human body, which makes them equally suitable for use in medicine.",
publisher = "Association of Metallurgical Engineers of Serbia",
journal = "Metallurgical and Materials Data. Advanced Functional Materials",
title = "Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution",
pages = "11-7",
number = "1",
volume = "1",
doi = "10.56801/MMD3"
}

Mihajlović, D., Rakin, M., Bajat, J.,& Đokić, V.. (2023). Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution. in Metallurgical and Materials Data. Advanced Functional Materials
Association of Metallurgical Engineers of Serbia., 1(1), 7-11.
https://doi.org/10.56801/MMD3

Mihajlović D, Rakin M, Bajat J, Đokić V. Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution. in Metallurgical and Materials Data. Advanced Functional Materials. 2023;1(1):7-11.
doi:10.56801/MMD3 .

Mihajlović, Dragana, Rakin, Marko, Bajat, Jelena, Đokić, Veljko, "Corrosion Stability of the Anodized Ultrafine-Grained Titanium in the Human Body Solution" in Metallurgical and Materials Data. Advanced Functional Materials, 1, no. 1 (2023):7-11,
https://doi.org/10.56801/MMD3 . .

TY  - CONF
AU  - Mihajlović, Dragana R.
AU  - Rakin, Marko P.
AU  - Bajat, Jelena B.
AU  - Međo, Bojan I.
AU  - Đokić, Veljko R.
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6974
AB  - Titanium-based nanotubelayer was formed through the electrochemical anodization technique on
coarse-grained and ultrafine-grained Ti-13Nb-13Zr (wt.%) alloy, in 1M H3PO4 + NaF electrolyte
for 90 minutes. The nanotube layer morphology was analyzed using the scanning electron
microscopy (SEM) and the X-ray diffraction (XRD). The electrochemical impedance spectroscopy (EIS) technique was used to determine the corrosion resistance of the alloy before and after
electrochemical anodization. These materials were exposed to a solution simulating conditions in
the human body (Ringer'
s solution) with pH of 5.5 at a temperature of 37 ºC. In order to investigate
the titanium-based nanotube layer adhesion on alloy surface a scratch test was done. The scratch
test was performedon nanoindenter G200, Agilent Technologies, using an indenter Berkovichtype diamond tip with applying an increasing load up to 40 mN. It was established that electrochemical anodization led to the formation of the nanotube oxide layer on the surface of titaniumbased materials. Influence of the ultrafine-grained material structure on the homogeneity of the
nanotube layer obtained by electrochemical anodization has been noticed. Both coarse-grained
and ultrafine-grained alloy showed excellent corrosion resistance in Ringer’s solution. Moreover,
electrochemical anodization led to a decrease or an increase of the corrosion resistance of these
materials, depending on the nanotube layer morphology. The scratch test showed that plastic
deformation was present in the nanotube layer. The scratch resistance for the nanotube layer
failure was on the higher load, pointing to the good adhesion for the titanium-based nanotube layer
formed using electrochemical anodization.
PB  - Belgrade : Materials Research Society of Serbia
C3  - Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023
T1  - Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials
SP  - 171
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6974
ER  - 

@conference{
author = "Mihajlović, Dragana R. and Rakin, Marko P. and Bajat, Jelena B. and Međo, Bojan I. and Đokić, Veljko R.",
year = "2023",
abstract = "Titanium-based nanotubelayer was formed through the electrochemical anodization technique on
coarse-grained and ultrafine-grained Ti-13Nb-13Zr (wt.%) alloy, in 1M H3PO4 + NaF electrolyte
for 90 minutes. The nanotube layer morphology was analyzed using the scanning electron
microscopy (SEM) and the X-ray diffraction (XRD). The electrochemical impedance spectroscopy (EIS) technique was used to determine the corrosion resistance of the alloy before and after
electrochemical anodization. These materials were exposed to a solution simulating conditions in
the human body (Ringer'
s solution) with pH of 5.5 at a temperature of 37 ºC. In order to investigate
the titanium-based nanotube layer adhesion on alloy surface a scratch test was done. The scratch
test was performedon nanoindenter G200, Agilent Technologies, using an indenter Berkovichtype diamond tip with applying an increasing load up to 40 mN. It was established that electrochemical anodization led to the formation of the nanotube oxide layer on the surface of titaniumbased materials. Influence of the ultrafine-grained material structure on the homogeneity of the
nanotube layer obtained by electrochemical anodization has been noticed. Both coarse-grained
and ultrafine-grained alloy showed excellent corrosion resistance in Ringer’s solution. Moreover,
electrochemical anodization led to a decrease or an increase of the corrosion resistance of these
materials, depending on the nanotube layer morphology. The scratch test showed that plastic
deformation was present in the nanotube layer. The scratch resistance for the nanotube layer
failure was on the higher load, pointing to the good adhesion for the titanium-based nanotube layer
formed using electrochemical anodization.",
publisher = "Belgrade : Materials Research Society of Serbia",
journal = "Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023",
title = "Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials",
pages = "171",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6974"
}

Mihajlović, D. R., Rakin, M. P., Bajat, J. B., Međo, B. I.,& Đokić, V. R.. (2023). Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials. in Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023
Belgrade : Materials Research Society of Serbia., 171.
https://hdl.handle.net/21.15107/rcub_technorep_6974

Mihajlović DR, Rakin MP, Bajat JB, Međo BI, Đokić VR. Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials. in Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023. 2023;:171.
https://hdl.handle.net/21.15107/rcub_technorep_6974 .

Mihajlović, Dragana R., Rakin, Marko P., Bajat, Jelena B., Međo, Bojan I., Đokić, Veljko R., "Corrosion and scratch resistance of the nanotube layer formed on the titanium-based materials" in Programme and The Book of Abstracts / Twenty-fourth Annual Conference YUCOMAT 2023, Herceg Novi, Montenegro, September 4 - 8, 2023 (2023):171,
https://hdl.handle.net/21.15107/rcub_technorep_6974 .

TY  - CONF
AU  - Mihajlović, Dragana
AU  - Međo, Bojan
AU  - Đokić, Veljko
AU  - Bajat, Jelena
AU  - Rakin, Marko
AU  - Putić, Slaviša
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/7172
AB  - Intenzivno plastično deformisanje (IPD, eng. Severe Plastic Deformation, SPD)  jesu različiti savremeni postupci čiji je osnovni cilj dobijanje sitnozrne strukture (eng. ultrafine-grained, UFG) metalnih materijala. Sitnozrni metalni materijali najčešće pokazuju poboljšana mehanička svojstva u odnosu na metalne materijale dobijene konvencionalnim postupcima izrade, dok je koroziona otpornost ovih materijala još uvek nedovoljno ispitana. Jedna od metoda intenzivnog plastičnog deformisanja je i metoda uvijanja pod visokim pritiskom (UVP, eng. High Pressure Torsion, HPT). U cilju ispitivanja uticaja nanostrukturne modifikacije površine na svojstva sitnozrnog komercijalnog čistog titana (korozionu postojanost, površinski modul elastičnosti i tvrdoću) u radu je urađena elektrohemijska anodizacija. Karakterizacija površinske modifikovane strukture kod sitnozrnog komercijalnog čistog titana urađena je primenom skenirajuće elektronske mikroskopije (eng. Scanning Electron Microscopy, SEM). Homogenost materijala nakon UVP postupka procenjen je merenjem mikrotvrdoće duž prečnika uzoraka primenom metode po Vikersu (eng. Vickers). Otpornost prema koroziji sitnozrnog komercijalnog čistog titana pre i posle elektrohemijske andizacije ispitana je primenom potenciodinamičke metode, pri čemu je pokazano povećanje korozione otpornosti u simuliranom rastvoru ljudskog organizma. Karakterizacija površine sitnozrnog komercijalnog čistog titana primenom nanoindentacije pokazala je smanjenje vrednosti površinskog modula elastičnosti i tvrdoće kod materijala sa nanostrukturnim oksidnim slojem, koje su bliže vrednostima koštanog tkiva u ljudskom organizmu.
AB  - Severe Plastic Deformation (SPD) are modern procedures whose main goal is to obtain an
ultrafine-grained structure of metallic materials. Ultrafine-grained metallic materials show
improved mechanical properties compared to metallic materials obtained by conventional
manufacturing methods, while the corrosion resistance of these materials is still insufficiently
tested. One of the methods of Severe Plastic Deformation is the method of High Pressure
Torsion (HPT). In order to examine the influence of nanostructural surface modification on
the properties of ultrafine-grained commercially pure titanium (corrosion resistance, surface
modulus of elasticity and hardness), electrochemical anodization was performed. The
characterization of the surface modified structure of ultrafine-grained commercially pure
titanium was performed using Scanning Electron Microscopy (SEM). The homogeneity of
the material after the HPT procedure was assessed by measuring the microhardness along the
diameter of the samples using the Vickers method. Corrosion resistance of ultrafine-grained
commercially pure titanium before and after electrochemical andization was tested using the
potentiodynamic method, where an increase corrosion resistance in a simulated solution of
the human organism was demonstrated. The characterization of the surface of the comercially
pure titanium using nanoindentation showed a decrease in the values of the surface modulus
of elasticity and hardness for titanium with a nanostructured oxide layer, which are closer to
the values of bone tissue in the human body.
PB  - Požarevac : Savez društava inženjera i tehničara grada Požarevca
PB  - Požarevac : Društvo hemičara, tehnologa i metalurga
C3  - Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine
T1  - Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini
T1  - The influence of nanostructure surface modification on the properties of commercially pure titanium for application in medicine
EP  - 60
SP  - 51
UR  - https://hdl.handle.net/21.15107/rcub_technorep_7172
ER  - 

@conference{
author = "Mihajlović, Dragana and Međo, Bojan and Đokić, Veljko and Bajat, Jelena and Rakin, Marko and Putić, Slaviša",
year = "2023",
abstract = "Intenzivno plastično deformisanje (IPD, eng. Severe Plastic Deformation, SPD)  jesu različiti savremeni postupci čiji je osnovni cilj dobijanje sitnozrne strukture (eng. ultrafine-grained, UFG) metalnih materijala. Sitnozrni metalni materijali najčešće pokazuju poboljšana mehanička svojstva u odnosu na metalne materijale dobijene konvencionalnim postupcima izrade, dok je koroziona otpornost ovih materijala još uvek nedovoljno ispitana. Jedna od metoda intenzivnog plastičnog deformisanja je i metoda uvijanja pod visokim pritiskom (UVP, eng. High Pressure Torsion, HPT). U cilju ispitivanja uticaja nanostrukturne modifikacije površine na svojstva sitnozrnog komercijalnog čistog titana (korozionu postojanost, površinski modul elastičnosti i tvrdoću) u radu je urađena elektrohemijska anodizacija. Karakterizacija površinske modifikovane strukture kod sitnozrnog komercijalnog čistog titana urađena je primenom skenirajuće elektronske mikroskopije (eng. Scanning Electron Microscopy, SEM). Homogenost materijala nakon UVP postupka procenjen je merenjem mikrotvrdoće duž prečnika uzoraka primenom metode po Vikersu (eng. Vickers). Otpornost prema koroziji sitnozrnog komercijalnog čistog titana pre i posle elektrohemijske andizacije ispitana je primenom potenciodinamičke metode, pri čemu je pokazano povećanje korozione otpornosti u simuliranom rastvoru ljudskog organizma. Karakterizacija površine sitnozrnog komercijalnog čistog titana primenom nanoindentacije pokazala je smanjenje vrednosti površinskog modula elastičnosti i tvrdoće kod materijala sa nanostrukturnim oksidnim slojem, koje su bliže vrednostima koštanog tkiva u ljudskom organizmu., Severe Plastic Deformation (SPD) are modern procedures whose main goal is to obtain an
ultrafine-grained structure of metallic materials. Ultrafine-grained metallic materials show
improved mechanical properties compared to metallic materials obtained by conventional
manufacturing methods, while the corrosion resistance of these materials is still insufficiently
tested. One of the methods of Severe Plastic Deformation is the method of High Pressure
Torsion (HPT). In order to examine the influence of nanostructural surface modification on
the properties of ultrafine-grained commercially pure titanium (corrosion resistance, surface
modulus of elasticity and hardness), electrochemical anodization was performed. The
characterization of the surface modified structure of ultrafine-grained commercially pure
titanium was performed using Scanning Electron Microscopy (SEM). The homogeneity of
the material after the HPT procedure was assessed by measuring the microhardness along the
diameter of the samples using the Vickers method. Corrosion resistance of ultrafine-grained
commercially pure titanium before and after electrochemical andization was tested using the
potentiodynamic method, where an increase corrosion resistance in a simulated solution of
the human organism was demonstrated. The characterization of the surface of the comercially
pure titanium using nanoindentation showed a decrease in the values of the surface modulus
of elasticity and hardness for titanium with a nanostructured oxide layer, which are closer to
the values of bone tissue in the human body.",
publisher = "Požarevac : Savez društava inženjera i tehničara grada Požarevca, Požarevac : Društvo hemičara, tehnologa i metalurga",
journal = "Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine",
title = "Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini, The influence of nanostructure surface modification on the properties of commercially pure titanium for application in medicine",
pages = "60-51",
url = "https://hdl.handle.net/21.15107/rcub_technorep_7172"
}

Mihajlović, D., Međo, B., Đokić, V., Bajat, J., Rakin, M.,& Putić, S.. (2023). Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini. in Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine
Požarevac : Savez društava inženjera i tehničara grada Požarevca., 51-60.
https://hdl.handle.net/21.15107/rcub_technorep_7172

Mihajlović D, Međo B, Đokić V, Bajat J, Rakin M, Putić S. Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini. in Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine. 2023;:51-60.
https://hdl.handle.net/21.15107/rcub_technorep_7172 .

Mihajlović, Dragana, Međo, Bojan, Đokić, Veljko, Bajat, Jelena, Rakin, Marko, Putić, Slaviša, "Uticaj nanostrukturne modifikacije površine na svojstva komercijalno čistog titana za primenu u medicini" in Zbornik radova / Savetovanje "Novi materijali i mogućnosti njihove primene", Požarevac, 2023 godine (2023):51-60,
https://hdl.handle.net/21.15107/rcub_technorep_7172 .

TY  - JOUR
AU  - Vujančević, Jelena
AU  - Andričević, Pavao
AU  - Đokić, Veljko
AU  - Blagojević, Vladimir
AU  - Pavlović, Vera P.
AU  - Ćirković, Jovana
AU  - Horváth, Endre
AU  - Forró, László
AU  - Karoui, Abdennaceur
AU  - Pavlović, Vladimir B.
AU  - Janaćković, Đorđe
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5921
AB  - In this study, we report the influence of vanadium oxide (VO), as a photosensitive component, on the photoactivity of TiO2 nanotubes (TNTs). A series of TNTs of varying tube diameter were synthesized by the anodization of titanium foils at different voltages, while vanadium oxide was deposited on TNTs by wet chemical deposition. An improvement in the optical properties of nanotubes was observed after the deposition of vanadium oxide. An improvement in the optical properties (redshift in UV-Vis spectra) of TNTs and TNT/VO was noted. The photocatalytic activity was improved with increasing tube diameter, while it was weakened after the deposition of VO. Furthermore, photoactivity was investigated in photodiodes based on TNTs or TNT/VO and single crystals of CH3NH3PbI3. The photoelectric measurement revealed that different TNT diameters did not influence the I-V characteristic of the photodiodes, while the deposition of VO improved the photocurrent for smaller TNTs.
PB  - MDPI
T2  - Catalysts
T1  - Effect of the Deposition of Vanadium-Oxide on the Photocatalytic Activity of TiO2 Nanotubes and Its Photodiode Performance Interfaced with CH3NH3PbI3 Single Crystal
IS  - 2
SP  - 352
VL  - 13
DO  - 10.3390/catal13020352
ER  - 

@article{
author = "Vujančević, Jelena and Andričević, Pavao and Đokić, Veljko and Blagojević, Vladimir and Pavlović, Vera P. and Ćirković, Jovana and Horváth, Endre and Forró, László and Karoui, Abdennaceur and Pavlović, Vladimir B. and Janaćković, Đorđe",
year = "2023",
abstract = "In this study, we report the influence of vanadium oxide (VO), as a photosensitive component, on the photoactivity of TiO2 nanotubes (TNTs). A series of TNTs of varying tube diameter were synthesized by the anodization of titanium foils at different voltages, while vanadium oxide was deposited on TNTs by wet chemical deposition. An improvement in the optical properties of nanotubes was observed after the deposition of vanadium oxide. An improvement in the optical properties (redshift in UV-Vis spectra) of TNTs and TNT/VO was noted. The photocatalytic activity was improved with increasing tube diameter, while it was weakened after the deposition of VO. Furthermore, photoactivity was investigated in photodiodes based on TNTs or TNT/VO and single crystals of CH3NH3PbI3. The photoelectric measurement revealed that different TNT diameters did not influence the I-V characteristic of the photodiodes, while the deposition of VO improved the photocurrent for smaller TNTs.",
publisher = "MDPI",
journal = "Catalysts",
title = "Effect of the Deposition of Vanadium-Oxide on the Photocatalytic Activity of TiO2 Nanotubes and Its Photodiode Performance Interfaced with CH3NH3PbI3 Single Crystal",
number = "2",
pages = "352",
volume = "13",
doi = "10.3390/catal13020352"
}

Vujančević, J., Andričević, P., Đokić, V., Blagojević, V., Pavlović, V. P., Ćirković, J., Horváth, E., Forró, L., Karoui, A., Pavlović, V. B.,& Janaćković, Đ.. (2023). Effect of the Deposition of Vanadium-Oxide on the Photocatalytic Activity of TiO2 Nanotubes and Its Photodiode Performance Interfaced with CH3NH3PbI3 Single Crystal. in Catalysts
MDPI., 13(2), 352.
https://doi.org/10.3390/catal13020352

Vujančević J, Andričević P, Đokić V, Blagojević V, Pavlović VP, Ćirković J, Horváth E, Forró L, Karoui A, Pavlović VB, Janaćković Đ. Effect of the Deposition of Vanadium-Oxide on the Photocatalytic Activity of TiO2 Nanotubes and Its Photodiode Performance Interfaced with CH3NH3PbI3 Single Crystal. in Catalysts. 2023;13(2):352.
doi:10.3390/catal13020352 .

Vujančević, Jelena, Andričević, Pavao, Đokić, Veljko, Blagojević, Vladimir, Pavlović, Vera P., Ćirković, Jovana, Horváth, Endre, Forró, László, Karoui, Abdennaceur, Pavlović, Vladimir B., Janaćković, Đorđe, "Effect of the Deposition of Vanadium-Oxide on the Photocatalytic Activity of TiO2 Nanotubes and Its Photodiode Performance Interfaced with CH3NH3PbI3 Single Crystal" in Catalysts, 13, no. 2 (2023):352,
https://doi.org/10.3390/catal13020352 . .

TY  - CONF
AU  - Barjaktarević, Dragana R.
AU  - Rakin, Marko P.
AU  - Međo, Bojan I.
AU  - Radosavljević, Zoran M.
AU  - Đokić, Veljko R.
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6018
AB  - Titanium alloys are metal materials widely used in medicine owing to their suitable characteristics such as low density, good corrosion resistance and biocompatibillity. High biocompatibility of the titanium alloy results from the creation of a spontaneous oxide layer with good adhesion and homogeneous morphology. In order to improve characteristics of the metallic materials for application in medicine, electrochemical methods that enable surface nanostructured modification are extensively used, and one of these methods is electrochemical anodization which makes it possible to obtain a nanostructured oxide layer composed of nanotubes on the surface of the metal material. The tested material was ultrafine-grained Ti-13Nb-13Zr (UFG TNZ) alloy obtained by the severe plastic deformation (SPD) processing using the high pressure torsion (HPT) process. Nanostructured oxide layer on the titanium alloy was formed by electrochemical anodization during the time period from 30 to 120 minutes. Characterization of the surface morphology obtained during different times of electrochemical anodization was done using scanning electron microscopy (SEM), while the topography and surface roughness of the titanium alloy before and after electrochemical anodization was determined using atomic force microscopy (AFM). Scratch test was used to determine the cross profile of the surface topography and critical load during scratching. Electrochemical anodization led to the formation of a nanostructured oxide layer on the surface of the titanium alloy. The obtained results indicated strong influence of the electrochemical anodization time on the oxide layer morphology - with its increase the diameter of the nanotubes increases too, while the wall thickness of nanotubes decreases. Also, electrochemical anodization led to an increase in the surface roughness.
PB  - Novi Sad : Faculty of Technology
C3  - Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad
T1  - THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY
EP  - 114
SP  - 105
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6018
ER  - 

@conference{
author = "Barjaktarević, Dragana R. and Rakin, Marko P. and Međo, Bojan I. and Radosavljević, Zoran M. and Đokić, Veljko R.",
year = "2023",
abstract = "Titanium alloys are metal materials widely used in medicine owing to their suitable characteristics such as low density, good corrosion resistance and biocompatibillity. High biocompatibility of the titanium alloy results from the creation of a spontaneous oxide layer with good adhesion and homogeneous morphology. In order to improve characteristics of the metallic materials for application in medicine, electrochemical methods that enable surface nanostructured modification are extensively used, and one of these methods is electrochemical anodization which makes it possible to obtain a nanostructured oxide layer composed of nanotubes on the surface of the metal material. The tested material was ultrafine-grained Ti-13Nb-13Zr (UFG TNZ) alloy obtained by the severe plastic deformation (SPD) processing using the high pressure torsion (HPT) process. Nanostructured oxide layer on the titanium alloy was formed by electrochemical anodization during the time period from 30 to 120 minutes. Characterization of the surface morphology obtained during different times of electrochemical anodization was done using scanning electron microscopy (SEM), while the topography and surface roughness of the titanium alloy before and after electrochemical anodization was determined using atomic force microscopy (AFM). Scratch test was used to determine the cross profile of the surface topography and critical load during scratching. Electrochemical anodization led to the formation of a nanostructured oxide layer on the surface of the titanium alloy. The obtained results indicated strong influence of the electrochemical anodization time on the oxide layer morphology - with its increase the diameter of the nanotubes increases too, while the wall thickness of nanotubes decreases. Also, electrochemical anodization led to an increase in the surface roughness.",
publisher = "Novi Sad : Faculty of Technology",
journal = "Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad",
title = "THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY",
pages = "114-105",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6018"
}

Barjaktarević, D. R., Rakin, M. P., Međo, B. I., Radosavljević, Z. M.,& Đokić, V. R.. (2023). THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY. in Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad
Novi Sad : Faculty of Technology., 105-114.
https://hdl.handle.net/21.15107/rcub_technorep_6018

Barjaktarević DR, Rakin MP, Međo BI, Radosavljević ZM, Đokić VR. THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY. in Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad. 2023;:105-114.
https://hdl.handle.net/21.15107/rcub_technorep_6018 .

Barjaktarević, Dragana R., Rakin, Marko P., Međo, Bojan I., Radosavljević, Zoran M., Đokić, Veljko R., "THE SURFACE CHARACTERIZATION OF THE ANODIZED ULTRAFINE-GRAINED Ti-13Nb-13Zr ALLOY" in Proceedings of the 2nd International Conference on Advanced Production and Processing ICAPP 2022, Novi Sad (2023):105-114,
https://hdl.handle.net/21.15107/rcub_technorep_6018 .

TY  - JOUR
AU  - Vojisavljević, Katarina
AU  - Savić, Slavica
AU  - Počuča-Nešić, Milica
AU  - Hodžić, Aden
AU  - Kriechbaum, Manfred
AU  - Ribić, Vesna
AU  - Rečnik, Aleksander
AU  - Vukašinović, Jelena
AU  - Branković, Goran
AU  - Đokić, Veljko
PY  - 2023
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5919
AB  - Developing highly efficient semiconductor metal oxide (SMOX) sensors capable of accurate and fast responses to environmental humidity is still a challenging task. In addition to a not so pronounced sensitivity to relative humidity change, most of the SMOXs cannot meet the criteria of real-time humidity sensing due to their long response/recovery time. The way to tackle this problem is to control adsorption/desorption processes, i.e., water-vapor molecular dynamics, over the sensor’s active layer through the powder and pore morphology design. With this in mind, a KIT-5-mediated synthesis was used to achieve mesoporous tin (IV) oxide replica (SnO2-R) with controlled pore size and ordering through template inversion and compared with a sol-gel synthesized powder (SnO2-SG). Unlike SnO2-SG, SnO2-R possessed a high specific surface area and quite an open pore structure, similar to the KIT-5, as observed by TEM, BET and SWAXS analyses. According to TEM, SnO2-R consisted of fine-grained globular particles and some percent of exaggerated, grown twinned crystals. The distinctive morphology of the SnO2-R-based sensor, with its specific pore structure and an increased number of oxygen-related defects associated with the powder preparation process and detected at the sensor surface by XPS analysis, contributed to excellent humidity sensing performances at room temperature, comprised of a low hysteresis error (3.7%), sensitivity of 406.8 kΩ/RH% and swift response/recovery speed (4 s/6 s).
PB  - MDPI
T2  - Molecules
T1  - KIT-5-Assisted Synthesis of Mesoporous SnO2 for High-Performance Humidity Sensors with a Swift Response/Recovery Speed
IS  - 4
SP  - 1754
VL  - 28
DO  - 10.3390/molecules28041754
ER  - 

@article{
author = "Vojisavljević, Katarina and Savić, Slavica and Počuča-Nešić, Milica and Hodžić, Aden and Kriechbaum, Manfred and Ribić, Vesna and Rečnik, Aleksander and Vukašinović, Jelena and Branković, Goran and Đokić, Veljko",
year = "2023",
abstract = "Developing highly efficient semiconductor metal oxide (SMOX) sensors capable of accurate and fast responses to environmental humidity is still a challenging task. In addition to a not so pronounced sensitivity to relative humidity change, most of the SMOXs cannot meet the criteria of real-time humidity sensing due to their long response/recovery time. The way to tackle this problem is to control adsorption/desorption processes, i.e., water-vapor molecular dynamics, over the sensor’s active layer through the powder and pore morphology design. With this in mind, a KIT-5-mediated synthesis was used to achieve mesoporous tin (IV) oxide replica (SnO2-R) with controlled pore size and ordering through template inversion and compared with a sol-gel synthesized powder (SnO2-SG). Unlike SnO2-SG, SnO2-R possessed a high specific surface area and quite an open pore structure, similar to the KIT-5, as observed by TEM, BET and SWAXS analyses. According to TEM, SnO2-R consisted of fine-grained globular particles and some percent of exaggerated, grown twinned crystals. The distinctive morphology of the SnO2-R-based sensor, with its specific pore structure and an increased number of oxygen-related defects associated with the powder preparation process and detected at the sensor surface by XPS analysis, contributed to excellent humidity sensing performances at room temperature, comprised of a low hysteresis error (3.7%), sensitivity of 406.8 kΩ/RH% and swift response/recovery speed (4 s/6 s).",
publisher = "MDPI",
journal = "Molecules",
title = "KIT-5-Assisted Synthesis of Mesoporous SnO2 for High-Performance Humidity Sensors with a Swift Response/Recovery Speed",
number = "4",
pages = "1754",
volume = "28",
doi = "10.3390/molecules28041754"
}

Vojisavljević, K., Savić, S., Počuča-Nešić, M., Hodžić, A., Kriechbaum, M., Ribić, V., Rečnik, A., Vukašinović, J., Branković, G.,& Đokić, V.. (2023). KIT-5-Assisted Synthesis of Mesoporous SnO2 for High-Performance Humidity Sensors with a Swift Response/Recovery Speed. in Molecules
MDPI., 28(4), 1754.
https://doi.org/10.3390/molecules28041754

Vojisavljević K, Savić S, Počuča-Nešić M, Hodžić A, Kriechbaum M, Ribić V, Rečnik A, Vukašinović J, Branković G, Đokić V. KIT-5-Assisted Synthesis of Mesoporous SnO2 for High-Performance Humidity Sensors with a Swift Response/Recovery Speed. in Molecules. 2023;28(4):1754.
doi:10.3390/molecules28041754 .

Vojisavljević, Katarina, Savić, Slavica, Počuča-Nešić, Milica, Hodžić, Aden, Kriechbaum, Manfred, Ribić, Vesna, Rečnik, Aleksander, Vukašinović, Jelena, Branković, Goran, Đokić, Veljko, "KIT-5-Assisted Synthesis of Mesoporous SnO2 for High-Performance Humidity Sensors with a Swift Response/Recovery Speed" in Molecules, 28, no. 4 (2023):1754,
https://doi.org/10.3390/molecules28041754 . .

TY  - CONF
AU  - Rakin, Marko
AU  - Barjaktarević, Dragana
AU  - Međo, Bojan
AU  - Đokić, Veljko
AU  - Gubeljak, Nenad
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6012
AB  - The intent of the study was to modify virgin biomedical Ti-13Nb-13Zr alloy in aim to realize whether applied modifications could improve mechanical properties. Two groups of modifications were applied to the prepared samples: structural modification achieved by severe plastic deformation (SPD) and modification of alloy surface obtained by electrochemical method. Structural modification was performed by using high pressure torsion (HPT) as one of the SPD methods. Pressure of 4.1 GPa was applied and up to 5 rotations were made at room temperature. After HPT treatment an ultrafine-grained (UFG) structure was obtained. The homogeneity of the UFG alloy was checked by using Vickers microhardness tester. Electrochemical anodization was done in the 1M H3PO4 + NaF electrolyte during 90 minutes, resulting in formation of an oxide layer on the alloy surface. Surface roughness was determined using an atomic force microscope. Tensile properties of the alloy before and after electrochemical anodization and HPT processing were determined. The scanning electron microscopy was used to characterize both morphology of anodized surfaces and the fracture surfaces after the tensile tests. 
The HPT treated alloy has higher values of tensile strength and modulus of elasticity and lower value of plasticity than the virgin alloy. Surface modification of virgin alloy leads to a decrease of these values compared to non-treated samples and practically has no influence on tensile properties on the UFG alloy. Mechanical properties of the surface – modulus of elasticity and nanohardness were determined using a nanoindentation test. The surfaces of anodized alloys (both virgin and HPT treated) have lower modulus of elasticity than surfaces of non-anodized ones.
C3  - 4th Virtual Congress on Materials Science & Engineering
T1  - Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6012
ER  - 

@conference{
author = "Rakin, Marko and Barjaktarević, Dragana and Međo, Bojan and Đokić, Veljko and Gubeljak, Nenad",
year = "2022",
abstract = "The intent of the study was to modify virgin biomedical Ti-13Nb-13Zr alloy in aim to realize whether applied modifications could improve mechanical properties. Two groups of modifications were applied to the prepared samples: structural modification achieved by severe plastic deformation (SPD) and modification of alloy surface obtained by electrochemical method. Structural modification was performed by using high pressure torsion (HPT) as one of the SPD methods. Pressure of 4.1 GPa was applied and up to 5 rotations were made at room temperature. After HPT treatment an ultrafine-grained (UFG) structure was obtained. The homogeneity of the UFG alloy was checked by using Vickers microhardness tester. Electrochemical anodization was done in the 1M H3PO4 + NaF electrolyte during 90 minutes, resulting in formation of an oxide layer on the alloy surface. Surface roughness was determined using an atomic force microscope. Tensile properties of the alloy before and after electrochemical anodization and HPT processing were determined. The scanning electron microscopy was used to characterize both morphology of anodized surfaces and the fracture surfaces after the tensile tests. 
The HPT treated alloy has higher values of tensile strength and modulus of elasticity and lower value of plasticity than the virgin alloy. Surface modification of virgin alloy leads to a decrease of these values compared to non-treated samples and practically has no influence on tensile properties on the UFG alloy. Mechanical properties of the surface – modulus of elasticity and nanohardness were determined using a nanoindentation test. The surfaces of anodized alloys (both virgin and HPT treated) have lower modulus of elasticity than surfaces of non-anodized ones.",
journal = "4th Virtual Congress on Materials Science & Engineering",
title = "Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6012"
}

Rakin, M., Barjaktarević, D., Međo, B., Đokić, V.,& Gubeljak, N.. (2022). Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation. in 4th Virtual Congress on Materials Science & Engineering.
https://hdl.handle.net/21.15107/rcub_technorep_6012

Rakin M, Barjaktarević D, Međo B, Đokić V, Gubeljak N. Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation. in 4th Virtual Congress on Materials Science & Engineering. 2022;.
https://hdl.handle.net/21.15107/rcub_technorep_6012 .

Rakin, Marko, Barjaktarević, Dragana, Međo, Bojan, Đokić, Veljko, Gubeljak, Nenad, "Mechanical characterization of surface modified Ti-based alloy before and after severe plastic deformation" in 4th Virtual Congress on Materials Science & Engineering (2022),
https://hdl.handle.net/21.15107/rcub_technorep_6012 .

TY  - JOUR
AU  - Ivanovska, Aleksandra
AU  - Maletić, Slavica
AU  - Đokić, Veljko
AU  - Tadić, Nenad
AU  - Kostić, Mirjana
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5102
AB  - The electro-physical properties of raw, alkali and oxidatively modified jute fabrics were investigated as complex phenomena of the interactions between the fabrics’ chemical composition, carboxyl group content, crystallinity, structural characteristics, moisture sorption, and frequency of the electric field. At 80% relative air humidity, chemically modified jute fabrics have 38–179% and 1.7–5.4 times higher dielectric loss tangent and effective relative dielectric permeability compared to unmodified. To further improve these properties, fabrics were treated with CuSO4 and Cu-based nanoparticles were in situ synthesized on their surfaces by reduction. A few smaller agglomerates of Cu-based nanoparticles were observed across the alkali modified fabric's surface, while smaller irregularly shaped and larger agglomerates were distributed over the oxidatively modified fabric's surface. Regardless of the type of synthesized nanostructures (metallic Cu, copper oxide (Cu2O or CuO) or their mixtures), excellent fabrics’ effective relative dielectric permeability is guaranteed. Precisely, exploitation in specific conditions that contribute to copper reduction will make jute fabrics able to store 21–163 times more energy from an external electric field than before the exploitation, which will extend their lifetime. On the other hand, with increasing the total content of Cu after the reduction and formation of agglomerates of Cu-based nanoparticles, the movements of cellulose, hemicelluloses, and lignin molecules become difficult resulting in lower energy dissipation within the chemically modified than within unmodified fabric. Applied chemical modification and coating with Cu-based nanoparticles enables designing fabrics with predictable electro-physical properties, which is very important from the application point of view.
PB  - Elsevier B.V.
T2  - Industrial Crops and Products
T1  - Effect of chemical modifications and coating with Cu-based nanoparticles on the electro-physical properties of jute fabrics in a condition of high humidity
SP  - 114792
VL  - 180
DO  - 10.1016/j.indcrop.2022.114792
ER  - 

@article{
author = "Ivanovska, Aleksandra and Maletić, Slavica and Đokić, Veljko and Tadić, Nenad and Kostić, Mirjana",
year = "2022",
abstract = "The electro-physical properties of raw, alkali and oxidatively modified jute fabrics were investigated as complex phenomena of the interactions between the fabrics’ chemical composition, carboxyl group content, crystallinity, structural characteristics, moisture sorption, and frequency of the electric field. At 80% relative air humidity, chemically modified jute fabrics have 38–179% and 1.7–5.4 times higher dielectric loss tangent and effective relative dielectric permeability compared to unmodified. To further improve these properties, fabrics were treated with CuSO4 and Cu-based nanoparticles were in situ synthesized on their surfaces by reduction. A few smaller agglomerates of Cu-based nanoparticles were observed across the alkali modified fabric's surface, while smaller irregularly shaped and larger agglomerates were distributed over the oxidatively modified fabric's surface. Regardless of the type of synthesized nanostructures (metallic Cu, copper oxide (Cu2O or CuO) or their mixtures), excellent fabrics’ effective relative dielectric permeability is guaranteed. Precisely, exploitation in specific conditions that contribute to copper reduction will make jute fabrics able to store 21–163 times more energy from an external electric field than before the exploitation, which will extend their lifetime. On the other hand, with increasing the total content of Cu after the reduction and formation of agglomerates of Cu-based nanoparticles, the movements of cellulose, hemicelluloses, and lignin molecules become difficult resulting in lower energy dissipation within the chemically modified than within unmodified fabric. Applied chemical modification and coating with Cu-based nanoparticles enables designing fabrics with predictable electro-physical properties, which is very important from the application point of view.",
publisher = "Elsevier B.V.",
journal = "Industrial Crops and Products",
title = "Effect of chemical modifications and coating with Cu-based nanoparticles on the electro-physical properties of jute fabrics in a condition of high humidity",
pages = "114792",
volume = "180",
doi = "10.1016/j.indcrop.2022.114792"
}

Ivanovska, A., Maletić, S., Đokić, V., Tadić, N.,& Kostić, M.. (2022). Effect of chemical modifications and coating with Cu-based nanoparticles on the electro-physical properties of jute fabrics in a condition of high humidity. in Industrial Crops and Products
Elsevier B.V.., 180, 114792.
https://doi.org/10.1016/j.indcrop.2022.114792

Ivanovska A, Maletić S, Đokić V, Tadić N, Kostić M. Effect of chemical modifications and coating with Cu-based nanoparticles on the electro-physical properties of jute fabrics in a condition of high humidity. in Industrial Crops and Products. 2022;180:114792.
doi:10.1016/j.indcrop.2022.114792 .

Ivanovska, Aleksandra, Maletić, Slavica, Đokić, Veljko, Tadić, Nenad, Kostić, Mirjana, "Effect of chemical modifications and coating with Cu-based nanoparticles on the electro-physical properties of jute fabrics in a condition of high humidity" in Industrial Crops and Products, 180 (2022):114792,
https://doi.org/10.1016/j.indcrop.2022.114792 . .

TY  - JOUR
AU  - Đokić, Veljko
AU  - Andričević, Pavao
AU  - Kollár, Márton
AU  - Ciers, Anastasiia
AU  - Arakcheeva, Alla
AU  - Vasiljević, Milica
AU  - Damjanović, Dragan
AU  - Forró, László
AU  - Horváth, Endre
AU  - Ivšić, Trpimir
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5133
AB  - An environmentally friendly analog of the prominent methylammonium lead halide perovskite, methylammonium bismuth bromide (MA3 Bi2 Br9 ), was prepared and investigated in the form of powder, single crystals and nanowires. Complete characterization via synchrotron X-ray diffraction data showed that the bulk crystal does not incorporate water into the structure. At the same time, water is absorbed on the surface of the crystal, and this modification leads to the changes in the resistivity of the material, thus making MA3 Bi2 Br9 an excellent candidate for use as a humidity sensor. The novel sensor was prepared from powder-pressed pellets with attached carbon electrodes and was characterized by being able to detect relative humidity over the full range (0.7–96% RH) at ambient temperature. Compared to commercial and literature values, the response and recovery times are very fast (down to 1.5 s/1.5 s).
PB  - MDPI
T2  - Crystals
T1  - Fast Lead-Free Humidity Sensor Based on Hybrid Halide Perovskite
IS  - 4
SP  - 547
VL  - 12
DO  - 10.3390/cryst12040547
ER  - 

@article{
author = "Đokić, Veljko and Andričević, Pavao and Kollár, Márton and Ciers, Anastasiia and Arakcheeva, Alla and Vasiljević, Milica and Damjanović, Dragan and Forró, László and Horváth, Endre and Ivšić, Trpimir",
year = "2022",
abstract = "An environmentally friendly analog of the prominent methylammonium lead halide perovskite, methylammonium bismuth bromide (MA3 Bi2 Br9 ), was prepared and investigated in the form of powder, single crystals and nanowires. Complete characterization via synchrotron X-ray diffraction data showed that the bulk crystal does not incorporate water into the structure. At the same time, water is absorbed on the surface of the crystal, and this modification leads to the changes in the resistivity of the material, thus making MA3 Bi2 Br9 an excellent candidate for use as a humidity sensor. The novel sensor was prepared from powder-pressed pellets with attached carbon electrodes and was characterized by being able to detect relative humidity over the full range (0.7–96% RH) at ambient temperature. Compared to commercial and literature values, the response and recovery times are very fast (down to 1.5 s/1.5 s).",
publisher = "MDPI",
journal = "Crystals",
title = "Fast Lead-Free Humidity Sensor Based on Hybrid Halide Perovskite",
number = "4",
pages = "547",
volume = "12",
doi = "10.3390/cryst12040547"
}

Đokić, V., Andričević, P., Kollár, M., Ciers, A., Arakcheeva, A., Vasiljević, M., Damjanović, D., Forró, L., Horváth, E.,& Ivšić, T.. (2022). Fast Lead-Free Humidity Sensor Based on Hybrid Halide Perovskite. in Crystals
MDPI., 12(4), 547.
https://doi.org/10.3390/cryst12040547

Đokić V, Andričević P, Kollár M, Ciers A, Arakcheeva A, Vasiljević M, Damjanović D, Forró L, Horváth E, Ivšić T. Fast Lead-Free Humidity Sensor Based on Hybrid Halide Perovskite. in Crystals. 2022;12(4):547.
doi:10.3390/cryst12040547 .

Đokić, Veljko, Andričević, Pavao, Kollár, Márton, Ciers, Anastasiia, Arakcheeva, Alla, Vasiljević, Milica, Damjanović, Dragan, Forró, László, Horváth, Endre, Ivšić, Trpimir, "Fast Lead-Free Humidity Sensor Based on Hybrid Halide Perovskite" in Crystals, 12, no. 4 (2022):547,
https://doi.org/10.3390/cryst12040547 . .

TY  - CONF
AU  - Barjaktarević, Dragana
AU  - Rakin, Marko
AU  - Veljović, Đorđe
AU  - Međo, Bojan
AU  - Đokić, Veljko
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5258
AB  - Nanostructured surface of Ti-13Nb-13Zr alloy (coarse-grained (CG), and ultrafine-grained (UFG), obtained by high pressure torsion - HPT) was formed using electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 30, 60, 90 and 120 minutes. The scanning electron microscopy (SEM) was used to characterise the morphology of the surface, while chemical characterization of the obtained nanostructured surface was performed using energy dispersive spectroscopy (EDS). The surface modulus of elasticity and hardness before and after the surface nanostructure modification, was examined using the nanoindentation test, while the analysis of deformation and damage of the nanostructured surface after nanoindentation was performed using SEM. Cytotoxicity of the tested alloys and cell culture viability were assessed using the tetrazolium salt colorimetric test (MTT test) using mouse fibroblasts (L-929) and human lung fibroblasts (MRC-5) in liquid medium. Morphology and adhesion of cells on the surface were analysed using SEM. The obtained results indicate the strong influence of time, as a parameter of anodization, on the surface morphology. Influence of the HPT processing on the homogeneity of the nanostructured surface obtained by electrochemical anodization has also been shown. The alloys before and after the surface nanostructure modification are adequate in their biocompatibility for use in the implantology. Characterization of the titanium-based materials surface using nanoindentation showed a decrease in the values of modulus of elasticity and hardness for materials with nanostructured surface, which are close to the values of bone tissue in the human body.
PB  - Materials Research Society of Srebia
C3  - Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS
T1  - Nanostructured surface modification and characterization of titanium based materials for medical application
SP  - 154
UR  - https://hdl.handle.net/21.15107/rcub_technorep_5258
ER  - 

@conference{
author = "Barjaktarević, Dragana and Rakin, Marko and Veljović, Đorđe and Međo, Bojan and Đokić, Veljko",
year = "2022",
abstract = "Nanostructured surface of Ti-13Nb-13Zr alloy (coarse-grained (CG), and ultrafine-grained (UFG), obtained by high pressure torsion - HPT) was formed using electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 30, 60, 90 and 120 minutes. The scanning electron microscopy (SEM) was used to characterise the morphology of the surface, while chemical characterization of the obtained nanostructured surface was performed using energy dispersive spectroscopy (EDS). The surface modulus of elasticity and hardness before and after the surface nanostructure modification, was examined using the nanoindentation test, while the analysis of deformation and damage of the nanostructured surface after nanoindentation was performed using SEM. Cytotoxicity of the tested alloys and cell culture viability were assessed using the tetrazolium salt colorimetric test (MTT test) using mouse fibroblasts (L-929) and human lung fibroblasts (MRC-5) in liquid medium. Morphology and adhesion of cells on the surface were analysed using SEM. The obtained results indicate the strong influence of time, as a parameter of anodization, on the surface morphology. Influence of the HPT processing on the homogeneity of the nanostructured surface obtained by electrochemical anodization has also been shown. The alloys before and after the surface nanostructure modification are adequate in their biocompatibility for use in the implantology. Characterization of the titanium-based materials surface using nanoindentation showed a decrease in the values of modulus of elasticity and hardness for materials with nanostructured surface, which are close to the values of bone tissue in the human body.",
publisher = "Materials Research Society of Srebia",
journal = "Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS",
title = "Nanostructured surface modification and characterization of titanium based materials for medical application",
pages = "154",
url = "https://hdl.handle.net/21.15107/rcub_technorep_5258"
}

Barjaktarević, D., Rakin, M., Veljović, Đ., Međo, B.,& Đokić, V.. (2022). Nanostructured surface modification and characterization of titanium based materials for medical application. in Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS
Materials Research Society of Srebia., 154.
https://hdl.handle.net/21.15107/rcub_technorep_5258

Barjaktarević D, Rakin M, Veljović Đ, Međo B, Đokić V. Nanostructured surface modification and characterization of titanium based materials for medical application. in Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS. 2022;:154.
https://hdl.handle.net/21.15107/rcub_technorep_5258 .

Barjaktarević, Dragana, Rakin, Marko, Veljović, Đorđe, Međo, Bojan, Đokić, Veljko, "Nanostructured surface modification and characterization of titanium based materials for medical application" in Twenty-third Annual Conference YUCOMAT 2022 &
Twelfth World Round Table Conference on Sintering XII WRTCS (2022):154,
https://hdl.handle.net/21.15107/rcub_technorep_5258 .

TY  - JOUR
AU  - Stanišić, Marija D.
AU  - Popović Kokar, Nikolina
AU  - Ristić, Predrag
AU  - Balaž, Ana Marija
AU  - Ognjanović, Miloš
AU  - Đokić, Veljko R.
AU  - Prodanović, Radivoje
AU  - Todorović, Tamara R.
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5269
AB  - Many articles in the literature deal with horseradish peroxidase (HRP) biomineralization, but none pay attention to the isoenzyme composition of commercial HRP or the influence of the carbohydrate component of the protein molecule on the biomineralization process. To study the impact of these factors, we performed periodate oxidation of commercial HRP and a purified HRP-C isoform for biomineralization within ZIF-8. With purified HRP, enzyme@ZIF-8 biocomposites with higher activity were obtained, while periodate oxidation of the carbohydrate component of both commercial HRP and purified HRP-C yields biocomposites with very high activity in acetate buffer that does not degrade the ZIF-8 structure. Using acetate instead of phosphate buffer can prevent the false high activity of HRP@ZIF-8 biocomposites caused by the degradation of ZIF-8 coating. At the same time, purification and especially oxidation of the carbohydrate component of enzymes prior to biomineralization lead to significantly improved activity of the biocomposites.
PB  - MDPI
T2  - Polymers
T1  - The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance
IS  - 22
SP  - 4834
VL  - 14
DO  - 10.3390/polym14224834
ER  - 

@article{
author = "Stanišić, Marija D. and Popović Kokar, Nikolina and Ristić, Predrag and Balaž, Ana Marija and Ognjanović, Miloš and Đokić, Veljko R. and Prodanović, Radivoje and Todorović, Tamara R.",
year = "2022",
abstract = "Many articles in the literature deal with horseradish peroxidase (HRP) biomineralization, but none pay attention to the isoenzyme composition of commercial HRP or the influence of the carbohydrate component of the protein molecule on the biomineralization process. To study the impact of these factors, we performed periodate oxidation of commercial HRP and a purified HRP-C isoform for biomineralization within ZIF-8. With purified HRP, enzyme@ZIF-8 biocomposites with higher activity were obtained, while periodate oxidation of the carbohydrate component of both commercial HRP and purified HRP-C yields biocomposites with very high activity in acetate buffer that does not degrade the ZIF-8 structure. Using acetate instead of phosphate buffer can prevent the false high activity of HRP@ZIF-8 biocomposites caused by the degradation of ZIF-8 coating. At the same time, purification and especially oxidation of the carbohydrate component of enzymes prior to biomineralization lead to significantly improved activity of the biocomposites.",
publisher = "MDPI",
journal = "Polymers",
title = "The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance",
number = "22",
pages = "4834",
volume = "14",
doi = "10.3390/polym14224834"
}

Stanišić, M. D., Popović Kokar, N., Ristić, P., Balaž, A. M., Ognjanović, M., Đokić, V. R., Prodanović, R.,& Todorović, T. R.. (2022). The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance. in Polymers
MDPI., 14(22), 4834.
https://doi.org/10.3390/polym14224834

Stanišić MD, Popović Kokar N, Ristić P, Balaž AM, Ognjanović M, Đokić VR, Prodanović R, Todorović TR. The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance. in Polymers. 2022;14(22):4834.
doi:10.3390/polym14224834 .

Stanišić, Marija D., Popović Kokar, Nikolina, Ristić, Predrag, Balaž, Ana Marija, Ognjanović, Miloš, Đokić, Veljko R., Prodanović, Radivoje, Todorović, Tamara R., "The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance" in Polymers, 14, no. 22 (2022):4834,
https://doi.org/10.3390/polym14224834 . .

TY  - DATA
AU  - Stanišić, Marija D.
AU  - Popović Kokar, Nikolina
AU  - Ristić, Predrag
AU  - Balaž, Ana Marija
AU  - Ognjanović, Miloš
AU  - Đokić, Veljko R.
AU  - Prodanović, Radivoje
AU  - Todorović, Tamara R.
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5951
T2  - Polymers
T1  - Primary research data for the article: Stanišić, M. D., Popović Kokar, N., Ristić, P., Balaž, A. M., Ognjanović, M., Đokić, V. R., Prodanović, R.,& Todorović, T. R.. (2022). The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance. in PolymersMDPI., 14(22), 4834.https://doi.org/10.3390/polym14224834
IS  - 22
VL  - 14
UR  - https://hdl.handle.net/21.15107/rcub_cherry_5740
ER  - 

@misc{
author = "Stanišić, Marija D. and Popović Kokar, Nikolina and Ristić, Predrag and Balaž, Ana Marija and Ognjanović, Miloš and Đokić, Veljko R. and Prodanović, Radivoje and Todorović, Tamara R.",
year = "2022",
journal = "Polymers",
title = "Primary research data for the article: Stanišić, M. D., Popović Kokar, N., Ristić, P., Balaž, A. M., Ognjanović, M., Đokić, V. R., Prodanović, R.,& Todorović, T. R.. (2022). The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance. in PolymersMDPI., 14(22), 4834.https://doi.org/10.3390/polym14224834",
number = "22",
volume = "14",
url = "https://hdl.handle.net/21.15107/rcub_cherry_5740"
}

Stanišić, M. D., Popović Kokar, N., Ristić, P., Balaž, A. M., Ognjanović, M., Đokić, V. R., Prodanović, R.,& Todorović, T. R.. (2022). Primary research data for the article: Stanišić, M. D., Popović Kokar, N., Ristić, P., Balaž, A. M., Ognjanović, M., Đokić, V. R., Prodanović, R.,& Todorović, T. R.. (2022). The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance. in PolymersMDPI., 14(22), 4834.https://doi.org/10.3390/polym14224834. in Polymers, 14(22).
https://hdl.handle.net/21.15107/rcub_cherry_5740

Stanišić MD, Popović Kokar N, Ristić P, Balaž AM, Ognjanović M, Đokić VR, Prodanović R, Todorović TR. Primary research data for the article: Stanišić, M. D., Popović Kokar, N., Ristić, P., Balaž, A. M., Ognjanović, M., Đokić, V. R., Prodanović, R.,& Todorović, T. R.. (2022). The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance. in PolymersMDPI., 14(22), 4834.https://doi.org/10.3390/polym14224834. in Polymers. 2022;14(22).
https://hdl.handle.net/21.15107/rcub_cherry_5740 .

Stanišić, Marija D., Popović Kokar, Nikolina, Ristić, Predrag, Balaž, Ana Marija, Ognjanović, Miloš, Đokić, Veljko R., Prodanović, Radivoje, Todorović, Tamara R., "Primary research data for the article: Stanišić, M. D., Popović Kokar, N., Ristić, P., Balaž, A. M., Ognjanović, M., Đokić, V. R., Prodanović, R.,& Todorović, T. R.. (2022). The Influence of Isoenzyme Composition and Chemical Modification on Horseradish Peroxidase@ZIF-8 Biocomposite Performance. in PolymersMDPI., 14(22), 4834.https://doi.org/10.3390/polym14224834" in Polymers, 14, no. 22 (2022),
https://hdl.handle.net/21.15107/rcub_cherry_5740 .

TY  - CONF
AU  - Ristić, Predrag
AU  - Stanišić, Marija
AU  - Đokić, Veljko
AU  - Balaž, Ana Marija
AU  - Mitić, Dragana
AU  - Prodanović, Radivoje
AU  - Todorović, Tamara
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5952
AB  - The durability of enzymes in harsh conditions can be enhanced by immobilization within metal-organic frameworks(MOFs) via a process called biomimetic mineralisation. Zeolitic imidazolate framework-8 (ZIF-8) is widely used as aprotective coating to encapsulate proteins. The formation of nucleation centres and further biocomposite particlegrowth is entirely governed by the pure electrostatic interactions between the protein’s surface and positively chargedZn(II) metal ions. It was previously shown that enhancing these electrostatic interactions by a chemical modificationof surface amino acid residues can lead to a rapid biocomposite formation. However, a chemical modification ofcarbohydrate components by periodate oxidation for glycoproteins can serve as an alternative strategy. In the presentstudy, an industrially important enzyme glucose oxidase (GOx) was selected as a model system. Periodate oxidationof GOx by 2.5 mM sodium periodate increased negative charge on the enzyme molecule. Biomineralizationexperiments with oxidized GOx resulted in higher specific activity, effectiveness factor, and higher thermostability ofthe ZIF-8 biocomposites.
C3  - Book of abstracts - NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece
T1  - Periodate oxidized glucose oxidase@ZIF-8 nanocomposite
EP  - 138
SP  - 138
UR  - https://hdl.handle.net/21.15107/rcub_cherry_5753
ER  - 

@conference{
author = "Ristić, Predrag and Stanišić, Marija and Đokić, Veljko and Balaž, Ana Marija and Mitić, Dragana and Prodanović, Radivoje and Todorović, Tamara",
year = "2022",
abstract = "The durability of enzymes in harsh conditions can be enhanced by immobilization within metal-organic frameworks(MOFs) via a process called biomimetic mineralisation. Zeolitic imidazolate framework-8 (ZIF-8) is widely used as aprotective coating to encapsulate proteins. The formation of nucleation centres and further biocomposite particlegrowth is entirely governed by the pure electrostatic interactions between the protein’s surface and positively chargedZn(II) metal ions. It was previously shown that enhancing these electrostatic interactions by a chemical modificationof surface amino acid residues can lead to a rapid biocomposite formation. However, a chemical modification ofcarbohydrate components by periodate oxidation for glycoproteins can serve as an alternative strategy. In the presentstudy, an industrially important enzyme glucose oxidase (GOx) was selected as a model system. Periodate oxidationof GOx by 2.5 mM sodium periodate increased negative charge on the enzyme molecule. Biomineralizationexperiments with oxidized GOx resulted in higher specific activity, effectiveness factor, and higher thermostability ofthe ZIF-8 biocomposites.",
journal = "Book of abstracts - NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece",
title = "Periodate oxidized glucose oxidase@ZIF-8 nanocomposite",
pages = "138-138",
url = "https://hdl.handle.net/21.15107/rcub_cherry_5753"
}

Ristić, P., Stanišić, M., Đokić, V., Balaž, A. M., Mitić, D., Prodanović, R.,& Todorović, T.. (2022). Periodate oxidized glucose oxidase@ZIF-8 nanocomposite. in Book of abstracts - NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece, 138-138.
https://hdl.handle.net/21.15107/rcub_cherry_5753

Ristić P, Stanišić M, Đokić V, Balaž AM, Mitić D, Prodanović R, Todorović T. Periodate oxidized glucose oxidase@ZIF-8 nanocomposite. in Book of abstracts - NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece. 2022;:138-138.
https://hdl.handle.net/21.15107/rcub_cherry_5753 .

Ristić, Predrag, Stanišić, Marija, Đokić, Veljko, Balaž, Ana Marija, Mitić, Dragana, Prodanović, Radivoje, Todorović, Tamara, "Periodate oxidized glucose oxidase@ZIF-8 nanocomposite" in Book of abstracts - NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece (2022):138-138,
https://hdl.handle.net/21.15107/rcub_cherry_5753 .

TY  - CONF
AU  - Stanišić, Marija
AU  - Ristić, Predrag
AU  - Đokić, Veljko
AU  - Balaž, Ana Marija
AU  - Prodanović, Radivoje
AU  - Todorović, Tamara
PY  - 2022
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5953
AB  - Metal-organic frameworks (MOFs) are a class of materials well-known for their high degree of crystallinity andultrahigh porosity. Modular synthesis from organic linkers and metal nodes allows for precise control of structure,pore size and chemical functionality of MOFs. Recently, MOFs have been explored for their potential to form novelbiocomposites with proteins by a process termed biomimetic mineralization. These novel MOF biocomposites showgreat promise for application to industrial biocatalysis where strategies for enhancing enzyme stability are ofsignificant interest. The protective capacity and applications of biomimetically mineralized biomacromolecule zeoliticimidazolate framework (ZIF-8) composites are likely dependent on the charge of the biomolecule and the topologyof the mineralized ZIF-8 coating. Herein, we identify conditions to reliably yield the porous periodate oxidizedhorseradish peroxidase@ZIF-8 sodalite topology biocomposite in preference to other more dense phases.
C3  - NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece
T1  - Periodate oxidized horseradish peroxidase@ZIF-8 nanocomposite
EP  - 138
SP  - 138
UR  - https://hdl.handle.net/21.15107/rcub_cherry_5752
ER  - 

@conference{
author = "Stanišić, Marija and Ristić, Predrag and Đokić, Veljko and Balaž, Ana Marija and Prodanović, Radivoje and Todorović, Tamara",
year = "2022",
abstract = "Metal-organic frameworks (MOFs) are a class of materials well-known for their high degree of crystallinity andultrahigh porosity. Modular synthesis from organic linkers and metal nodes allows for precise control of structure,pore size and chemical functionality of MOFs. Recently, MOFs have been explored for their potential to form novelbiocomposites with proteins by a process termed biomimetic mineralization. These novel MOF biocomposites showgreat promise for application to industrial biocatalysis where strategies for enhancing enzyme stability are ofsignificant interest. The protective capacity and applications of biomimetically mineralized biomacromolecule zeoliticimidazolate framework (ZIF-8) composites are likely dependent on the charge of the biomolecule and the topologyof the mineralized ZIF-8 coating. Herein, we identify conditions to reliably yield the porous periodate oxidizedhorseradish peroxidase@ZIF-8 sodalite topology biocomposite in preference to other more dense phases.",
journal = "NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece",
title = "Periodate oxidized horseradish peroxidase@ZIF-8 nanocomposite",
pages = "138-138",
url = "https://hdl.handle.net/21.15107/rcub_cherry_5752"
}

Stanišić, M., Ristić, P., Đokić, V., Balaž, A. M., Prodanović, R.,& Todorović, T.. (2022). Periodate oxidized horseradish peroxidase@ZIF-8 nanocomposite. in NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece, 138-138.
https://hdl.handle.net/21.15107/rcub_cherry_5752

Stanišić M, Ristić P, Đokić V, Balaž AM, Prodanović R, Todorović T. Periodate oxidized horseradish peroxidase@ZIF-8 nanocomposite. in NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece. 2022;:138-138.
https://hdl.handle.net/21.15107/rcub_cherry_5752 .

Stanišić, Marija, Ristić, Predrag, Đokić, Veljko, Balaž, Ana Marija, Prodanović, Radivoje, Todorović, Tamara, "Periodate oxidized horseradish peroxidase@ZIF-8 nanocomposite" in NANOTEXNOLOGY NN22, 19th International Conference on Nanosciences & Nanotechnologies, 5-8 July 2022, Thessaloniki, Greece (2022):138-138,
https://hdl.handle.net/21.15107/rcub_cherry_5752 .

TY  - CONF
AU  - Rakin, Marko
AU  - Barjaktarević, Dragana
AU  - Đokić, Veljko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/6178
C3  - Virtual Event: Global Summit on Future of Materials Science and Research
T1  - Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application.
EP  - 30
SP  - 29
UR  - https://hdl.handle.net/21.15107/rcub_technorep_6178
ER  - 

@conference{
author = "Rakin, Marko and Barjaktarević, Dragana and Đokić, Veljko",
year = "2021",
journal = "Virtual Event: Global Summit on Future of Materials Science and Research",
title = "Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application.",
pages = "30-29",
url = "https://hdl.handle.net/21.15107/rcub_technorep_6178"
}

Rakin, M., Barjaktarević, D.,& Đokić, V.. (2021). Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application.. in Virtual Event: Global Summit on Future of Materials Science and Research, 29-30.
https://hdl.handle.net/21.15107/rcub_technorep_6178

Rakin M, Barjaktarević D, Đokić V. Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application.. in Virtual Event: Global Summit on Future of Materials Science and Research. 2021;:29-30.
https://hdl.handle.net/21.15107/rcub_technorep_6178 .

Rakin, Marko, Barjaktarević, Dragana, Đokić, Veljko, "Nanostructured surface modification of coarse-grained and ultrafine-grained Ti-13Nb-13Zr alloy for biomedical application." in Virtual Event: Global Summit on Future of Materials Science and Research (2021):29-30,
https://hdl.handle.net/21.15107/rcub_technorep_6178 .

TY  - JOUR
AU  - Stanisic, Marija D.
AU  - Popovic Kokar, Nikolina
AU  - Ristic, Predrag
AU  - Balaz, Ana Marija
AU  - Sencanski, Milan
AU  - Ognjanovic, Milos
AU  - Đokić, Veljko
AU  - Prodanovic, Radivoje
AU  - Todorovic, Tamara R.
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4817
AB  - Zeolitic imidazolate framework-8 (ZIF-8) is widely used as a protective coating to encapsulate proteins via biomimetic mineralization. The formation of nucleation centers and further biocomposite crystal growth is entirely governed by the pure electrostatic interactions between the protein's surface and the positively charged Zn(II) metal ions. It was previously shown that enhancing these electrostatic interactions by a chemical modification of surface amino acid residues can lead to a rapid biocomposite crystal formation. However, a chemical modification of carbohydrate components by periodate oxidation for glycoproteins can serve as an alternative strategy. In the present study, an industrially important enzyme glucose oxidase (GOx) was selected as a model system. Periodate oxidation of GOx by 2.5 mM sodium periodate increased negative charge on the enzyme molecule, from -10.2 to -36.9 mV, as shown by zeta potential measurements and native PAGE electrophoresis. Biomineralization experiments with oxidized GOx resulted in higher specific activity, effectiveness factor, and higher thermostability of the ZIF-8 biocomposites. Periodate oxidation of carbohydrate components for glycoproteins can serve as a facile and general method for facilitating the biomimetic mineralization of other industrially relevant glycoproteins.
T2  - Polymers
T1  - Chemical Modification of Glycoproteins' Carbohydrate Moiety as a General Strategy for the Synthesis of Efficient Biocatalysts by Biomimetic Mineralization: The Case of Glucose Oxidase
EP  - 3875
IS  - 22
VL  - 13
DO  - 10.3390/polym13223875
ER  - 

@article{
author = "Stanisic, Marija D. and Popovic Kokar, Nikolina and Ristic, Predrag and Balaz, Ana Marija and Sencanski, Milan and Ognjanovic, Milos and Đokić, Veljko and Prodanovic, Radivoje and Todorovic, Tamara R.",
year = "2021",
abstract = "Zeolitic imidazolate framework-8 (ZIF-8) is widely used as a protective coating to encapsulate proteins via biomimetic mineralization. The formation of nucleation centers and further biocomposite crystal growth is entirely governed by the pure electrostatic interactions between the protein's surface and the positively charged Zn(II) metal ions. It was previously shown that enhancing these electrostatic interactions by a chemical modification of surface amino acid residues can lead to a rapid biocomposite crystal formation. However, a chemical modification of carbohydrate components by periodate oxidation for glycoproteins can serve as an alternative strategy. In the present study, an industrially important enzyme glucose oxidase (GOx) was selected as a model system. Periodate oxidation of GOx by 2.5 mM sodium periodate increased negative charge on the enzyme molecule, from -10.2 to -36.9 mV, as shown by zeta potential measurements and native PAGE electrophoresis. Biomineralization experiments with oxidized GOx resulted in higher specific activity, effectiveness factor, and higher thermostability of the ZIF-8 biocomposites. Periodate oxidation of carbohydrate components for glycoproteins can serve as a facile and general method for facilitating the biomimetic mineralization of other industrially relevant glycoproteins.",
journal = "Polymers",
title = "Chemical Modification of Glycoproteins' Carbohydrate Moiety as a General Strategy for the Synthesis of Efficient Biocatalysts by Biomimetic Mineralization: The Case of Glucose Oxidase",
pages = "3875",
number = "22",
volume = "13",
doi = "10.3390/polym13223875"
}

Stanisic, M. D., Popovic Kokar, N., Ristic, P., Balaz, A. M., Sencanski, M., Ognjanovic, M., Đokić, V., Prodanovic, R.,& Todorovic, T. R.. (2021). Chemical Modification of Glycoproteins' Carbohydrate Moiety as a General Strategy for the Synthesis of Efficient Biocatalysts by Biomimetic Mineralization: The Case of Glucose Oxidase. in Polymers, 13(22).
https://doi.org/10.3390/polym13223875

Stanisic MD, Popovic Kokar N, Ristic P, Balaz AM, Sencanski M, Ognjanovic M, Đokić V, Prodanovic R, Todorovic TR. Chemical Modification of Glycoproteins' Carbohydrate Moiety as a General Strategy for the Synthesis of Efficient Biocatalysts by Biomimetic Mineralization: The Case of Glucose Oxidase. in Polymers. 2021;13(22):null-3875.
doi:10.3390/polym13223875 .

Stanisic, Marija D., Popovic Kokar, Nikolina, Ristic, Predrag, Balaz, Ana Marija, Sencanski, Milan, Ognjanovic, Milos, Đokić, Veljko, Prodanovic, Radivoje, Todorovic, Tamara R., "Chemical Modification of Glycoproteins' Carbohydrate Moiety as a General Strategy for the Synthesis of Efficient Biocatalysts by Biomimetic Mineralization: The Case of Glucose Oxidase" in Polymers, 13, no. 22 (2021),
https://doi.org/10.3390/polym13223875 . .

TY  - JOUR
AU  - Ristić, Predrag
AU  - Filipović, Nenad
AU  - Blagojević, Vladimir
AU  - Ćirković, Jovana
AU  - Barta Hollo, Berta
AU  - Đokić, Veljko
AU  - Donnard, Morgan
AU  - Gulea, Mihaela
AU  - Marjanović, Ivana
AU  - Klisurić, Olivera R.
AU  - Todorović, Tamara R.
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4924
AB  - Four silver-based coordination polymers, {[Ag(L1)(2)]NO3}(infinity) (1), {[Ag(L1)(2)]ClO4}(infinity) (2), {[Ag(L2)(2)]NO3 center dot H2O}(infinity) (3) and {[Ag(L2)(2)]ClO4}(infinity) (4), were synthesized using the thiomorpholine-4-carbonitrile (L1) and piperazine-1,4-dicarbonitrile (L2) ligands. Compounds 1 and 2 are two-dimensional, while 3 and 4 are three-dimensional. L1 and L2 are 1,4-bis-monodentate ligands in all compounds, while Ag(i) ions are four-coordinated in a slightly distorted tetrahedral geometry. Topological analysis in standard representations suggests that underlying nets in 1 and 2 have an sql topology, while 3 and 4 exhibit a dia topology. Thermal analysis shows that 3 loses crystalline water at room temperature, while other compounds show good thermal stability. All compounds show good photocatalytic activity for photocatalytic degradation of the mordant blue 9 dye, with reaction rates in the range 0.029 to 0.061 min(-1). The best result was obtained for compound 4, which can be correlated to its largest lattice volume.
T2  - CrystEngComm
T1  - 2D and 3D silver-based coordination polymers with thiomorpholine-4-carbonitrile and piperazine-1,4-dicarbonitrile: structure, intermolecular interactions, photocatalysis, and thermal behavior
EP  - 4815
IS  - 27
SP  - 4799
VL  - 23
DO  - 10.1039/d1ce00394a
ER  - 

@article{
author = "Ristić, Predrag and Filipović, Nenad and Blagojević, Vladimir and Ćirković, Jovana and Barta Hollo, Berta and Đokić, Veljko and Donnard, Morgan and Gulea, Mihaela and Marjanović, Ivana and Klisurić, Olivera R. and Todorović, Tamara R.",
year = "2021",
abstract = "Four silver-based coordination polymers, {[Ag(L1)(2)]NO3}(infinity) (1), {[Ag(L1)(2)]ClO4}(infinity) (2), {[Ag(L2)(2)]NO3 center dot H2O}(infinity) (3) and {[Ag(L2)(2)]ClO4}(infinity) (4), were synthesized using the thiomorpholine-4-carbonitrile (L1) and piperazine-1,4-dicarbonitrile (L2) ligands. Compounds 1 and 2 are two-dimensional, while 3 and 4 are three-dimensional. L1 and L2 are 1,4-bis-monodentate ligands in all compounds, while Ag(i) ions are four-coordinated in a slightly distorted tetrahedral geometry. Topological analysis in standard representations suggests that underlying nets in 1 and 2 have an sql topology, while 3 and 4 exhibit a dia topology. Thermal analysis shows that 3 loses crystalline water at room temperature, while other compounds show good thermal stability. All compounds show good photocatalytic activity for photocatalytic degradation of the mordant blue 9 dye, with reaction rates in the range 0.029 to 0.061 min(-1). The best result was obtained for compound 4, which can be correlated to its largest lattice volume.",
journal = "CrystEngComm",
title = "2D and 3D silver-based coordination polymers with thiomorpholine-4-carbonitrile and piperazine-1,4-dicarbonitrile: structure, intermolecular interactions, photocatalysis, and thermal behavior",
pages = "4815-4799",
number = "27",
volume = "23",
doi = "10.1039/d1ce00394a"
}

Ristić, P., Filipović, N., Blagojević, V., Ćirković, J., Barta Hollo, B., Đokić, V., Donnard, M., Gulea, M., Marjanović, I., Klisurić, O. R.,& Todorović, T. R.. (2021). 2D and 3D silver-based coordination polymers with thiomorpholine-4-carbonitrile and piperazine-1,4-dicarbonitrile: structure, intermolecular interactions, photocatalysis, and thermal behavior. in CrystEngComm, 23(27), 4799-4815.
https://doi.org/10.1039/d1ce00394a

Ristić P, Filipović N, Blagojević V, Ćirković J, Barta Hollo B, Đokić V, Donnard M, Gulea M, Marjanović I, Klisurić OR, Todorović TR. 2D and 3D silver-based coordination polymers with thiomorpholine-4-carbonitrile and piperazine-1,4-dicarbonitrile: structure, intermolecular interactions, photocatalysis, and thermal behavior. in CrystEngComm. 2021;23(27):4799-4815.
doi:10.1039/d1ce00394a .

Ristić, Predrag, Filipović, Nenad, Blagojević, Vladimir, Ćirković, Jovana, Barta Hollo, Berta, Đokić, Veljko, Donnard, Morgan, Gulea, Mihaela, Marjanović, Ivana, Klisurić, Olivera R., Todorović, Tamara R., "2D and 3D silver-based coordination polymers with thiomorpholine-4-carbonitrile and piperazine-1,4-dicarbonitrile: structure, intermolecular interactions, photocatalysis, and thermal behavior" in CrystEngComm, 23, no. 27 (2021):4799-4815,
https://doi.org/10.1039/d1ce00394a . .

TY  - JOUR
AU  - Lazic, Biljana D.
AU  - Janjic, Svjetlana D.
AU  - Korica, Matea
AU  - Pejic, Biljana M.
AU  - Đokić, Veljko
AU  - Kostić, Mirjana
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/4970
AB  - Hydrogen peroxide represents an ecologically and economically acceptable agent for bleaching of flax fibers. The influence of hydrogen peroxide treatment under different conditions, i.e. hydrogen peroxide concentrations (1%, 2% and 4% w/v) and treatment temperature (50 degrees C, 80 degrees C and boiling temperature), on the chemical composition, electrokinetic and sorption properties and whiteness index of flax fibers, has been studied. The surface properties and water uptake behavior, i.e. swelling of untreated and treated flax fibers, were monitored through zeta potential measurements using the streaming potential method.The present research has found out that hydrogen peroxide simultaneously removes hemicelluloses and lignin from flax fibers. The ratio between the removal of hemicelluloses (hydrophilic component) and lignin (hydrophobic component), as well as changes in crystallinity, pore structure and carbonyl and carboxyl groups content, have a dominant effect on the electrokinetic, i.e. zeta potential versus pH and isoelectric point and sorption properties of the treated flax fiber. An increase of approximately three-to-four-fold in the whiteness index of the treated flax fibers has been observed. The established correlations between the modification conditions and properties of flax fibers, allow the utilization of hydrogen peroxide for bleaching and simultaneous fiber modification with the possibility of tailoringflax fibers properties. Graphic abstract
T2  - Cellulose
T1  - Electrokinetic and sorption properties of hydrogen peroxide treated flax fibers (Linum usitatissimum L.)
EP  - 2903
IS  - 5
SP  - 2889
VL  - 28
DO  - 10.1007/s10570-021-03686-0
ER  - 

@article{
author = "Lazic, Biljana D. and Janjic, Svjetlana D. and Korica, Matea and Pejic, Biljana M. and Đokić, Veljko and Kostić, Mirjana",
year = "2021",
abstract = "Hydrogen peroxide represents an ecologically and economically acceptable agent for bleaching of flax fibers. The influence of hydrogen peroxide treatment under different conditions, i.e. hydrogen peroxide concentrations (1%, 2% and 4% w/v) and treatment temperature (50 degrees C, 80 degrees C and boiling temperature), on the chemical composition, electrokinetic and sorption properties and whiteness index of flax fibers, has been studied. The surface properties and water uptake behavior, i.e. swelling of untreated and treated flax fibers, were monitored through zeta potential measurements using the streaming potential method.The present research has found out that hydrogen peroxide simultaneously removes hemicelluloses and lignin from flax fibers. The ratio between the removal of hemicelluloses (hydrophilic component) and lignin (hydrophobic component), as well as changes in crystallinity, pore structure and carbonyl and carboxyl groups content, have a dominant effect on the electrokinetic, i.e. zeta potential versus pH and isoelectric point and sorption properties of the treated flax fiber. An increase of approximately three-to-four-fold in the whiteness index of the treated flax fibers has been observed. The established correlations between the modification conditions and properties of flax fibers, allow the utilization of hydrogen peroxide for bleaching and simultaneous fiber modification with the possibility of tailoringflax fibers properties. Graphic abstract",
journal = "Cellulose",
title = "Electrokinetic and sorption properties of hydrogen peroxide treated flax fibers (Linum usitatissimum L.)",
pages = "2903-2889",
number = "5",
volume = "28",
doi = "10.1007/s10570-021-03686-0"
}

Lazic, B. D., Janjic, S. D., Korica, M., Pejic, B. M., Đokić, V.,& Kostić, M.. (2021). Electrokinetic and sorption properties of hydrogen peroxide treated flax fibers (Linum usitatissimum L.). in Cellulose, 28(5), 2889-2903.
https://doi.org/10.1007/s10570-021-03686-0

Lazic BD, Janjic SD, Korica M, Pejic BM, Đokić V, Kostić M. Electrokinetic and sorption properties of hydrogen peroxide treated flax fibers (Linum usitatissimum L.). in Cellulose. 2021;28(5):2889-2903.
doi:10.1007/s10570-021-03686-0 .

Lazic, Biljana D., Janjic, Svjetlana D., Korica, Matea, Pejic, Biljana M., Đokić, Veljko, Kostić, Mirjana, "Electrokinetic and sorption properties of hydrogen peroxide treated flax fibers (Linum usitatissimum L.)" in Cellulose, 28, no. 5 (2021):2889-2903,
https://doi.org/10.1007/s10570-021-03686-0 . .

TY  - CHAP
AU  - Barjaktarević, Dragana
AU  - Međo, Bojan
AU  - Đokić, Veljko
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5252
AB  - Lower value of modulus of elasticity, closer to that of a bone, is one of the crucial surface properties in accepting the implant material from the surrounding tissue, and reduces the possibility of slow disappearance of bone in contact with the implant. In the present study, ultrafine-grained (UFG) Ti-13Nb-13Zr alloy was obtained using high pressure torsion process (HPT) under a pressure of 4.1 GPa with a rotational speed of 0.2 rpm up to 5 rotations at room temperature. Nanostructured surface on coarse-grained (CG) and UFG Ti-13Nb-13Zr alloy was formed using electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 60 and 90 minutes. Scanning electron microscopy (SEM) was used to characterise the morphology of the surface, while nanomechanical properties of the surface, modulus of elasticity and nanohardness were determined using the nanoindentation test. Also, in order to characterise deformation of the nanotubes after nanoindentation test, SEM was done. It was shown that the nanotubular oxide layer was formed as result of the electrochemical anodization process during both anodizing times. The surface of anodized alloys has lower modulus of elasticity than surface of non-anodized ones. Anodized UFG alloy had the lowest modulus of elasticity of the surface when compared to other tested samples, which makes it more acceptable for biomedical usage.
PB  - Springer
T2  - Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies
T1  - Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization
EP  - 141
SP  - 123
VL  - 323
DO  - 10.1007/978-3-030-86009-7_7
ER  - 

@inbook{
author = "Barjaktarević, Dragana and Međo, Bojan and Đokić, Veljko and Rakin, Marko",
year = "2021",
abstract = "Lower value of modulus of elasticity, closer to that of a bone, is one of the crucial surface properties in accepting the implant material from the surrounding tissue, and reduces the possibility of slow disappearance of bone in contact with the implant. In the present study, ultrafine-grained (UFG) Ti-13Nb-13Zr alloy was obtained using high pressure torsion process (HPT) under a pressure of 4.1 GPa with a rotational speed of 0.2 rpm up to 5 rotations at room temperature. Nanostructured surface on coarse-grained (CG) and UFG Ti-13Nb-13Zr alloy was formed using electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 60 and 90 minutes. Scanning electron microscopy (SEM) was used to characterise the morphology of the surface, while nanomechanical properties of the surface, modulus of elasticity and nanohardness were determined using the nanoindentation test. Also, in order to characterise deformation of the nanotubes after nanoindentation test, SEM was done. It was shown that the nanotubular oxide layer was formed as result of the electrochemical anodization process during both anodizing times. The surface of anodized alloys has lower modulus of elasticity than surface of non-anodized ones. Anodized UFG alloy had the lowest modulus of elasticity of the surface when compared to other tested samples, which makes it more acceptable for biomedical usage.",
publisher = "Springer",
journal = "Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies",
booktitle = "Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization",
pages = "141-123",
volume = "323",
doi = "10.1007/978-3-030-86009-7_7"
}

Barjaktarević, D., Međo, B., Đokić, V.,& Rakin, M.. (2021). Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization. in Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies
Springer., 323, 123-141.
https://doi.org/10.1007/978-3-030-86009-7_7

Barjaktarević D, Međo B, Đokić V, Rakin M. Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization. in Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies. 2021;323:123-141.
doi:10.1007/978-3-030-86009-7_7 .

Barjaktarević, Dragana, Međo, Bojan, Đokić, Veljko, Rakin, Marko, "Morphology and nanomechanical properties of the ultrafine-grained Ti-13Nb-13Zr alloy surface obtained using electrochemical anodization" in Proceedings of the International Conference
of Experimental and Numerical Investigations
and New Technologies, 323 (2021):123-141,
https://doi.org/10.1007/978-3-030-86009-7_7 . .

TY  - CONF
AU  - Barjaktarević, Dragana
AU  - Đokić, Veljko
AU  - Stevanović, Sanja
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5253
AB  - Surface roughness is one of the influencing factors on the friction and wear mechanism of metallic materials. However, surface roughness of metallic biomaterials plays a major role in assessing the biocompatibility and adhesion of human cells of the surrounding bone tissue on the biomaterials surface. Namely, it is already known that as the surface roughness increases, contact surface with human cells increases, and thus their adhesion to the surface. In order to achieve adequate roughness and biocompatibility, it is often necessary to additionally subject the surface of the biomaterial to modification. 
In the present study, nanostructured oxide coating on the Ti-13Nb-13Zr alloy was formed by electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 60, 90, 120 minutes. The scanning electron microscopy (SEM) was used to analyse the nanostructured oxide coating morphology and showed that highly ordered nanotubular oxide layers were formed by electrochemical anodization. The atomic force microscopy (AFM) was used to characterise the surface topography before and after electrochemical anodization. Results showed that the surface had higher roughness after electrochemical anodization compared to initial surface of the alloy. It was also shown that increase of anodizing time induces increase of the surface roughness.
PB  - Univerzitet u Beogradu, Mašinski fakultet
C3  - Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology
T1  - Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy
EP  - 62
SP  - 59
UR  - https://hdl.handle.net/21.15107/rcub_technorep_5253
ER  - 

@conference{
author = "Barjaktarević, Dragana and Đokić, Veljko and Stevanović, Sanja and Rakin, Marko",
year = "2021",
abstract = "Surface roughness is one of the influencing factors on the friction and wear mechanism of metallic materials. However, surface roughness of metallic biomaterials plays a major role in assessing the biocompatibility and adhesion of human cells of the surrounding bone tissue on the biomaterials surface. Namely, it is already known that as the surface roughness increases, contact surface with human cells increases, and thus their adhesion to the surface. In order to achieve adequate roughness and biocompatibility, it is often necessary to additionally subject the surface of the biomaterial to modification. 
In the present study, nanostructured oxide coating on the Ti-13Nb-13Zr alloy was formed by electrochemical anodization in the 1M H3PO4 + NaF electrolyte, during 60, 90, 120 minutes. The scanning electron microscopy (SEM) was used to analyse the nanostructured oxide coating morphology and showed that highly ordered nanotubular oxide layers were formed by electrochemical anodization. The atomic force microscopy (AFM) was used to characterise the surface topography before and after electrochemical anodization. Results showed that the surface had higher roughness after electrochemical anodization compared to initial surface of the alloy. It was also shown that increase of anodizing time induces increase of the surface roughness.",
publisher = "Univerzitet u Beogradu, Mašinski fakultet",
journal = "Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology",
title = "Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy",
pages = "62-59",
url = "https://hdl.handle.net/21.15107/rcub_technorep_5253"
}

Barjaktarević, D., Đokić, V., Stevanović, S.,& Rakin, M.. (2021). Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy. in Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology
Univerzitet u Beogradu, Mašinski fakultet., 59-62.
https://hdl.handle.net/21.15107/rcub_technorep_5253

Barjaktarević D, Đokić V, Stevanović S, Rakin M. Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy. in Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology. 2021;:59-62.
https://hdl.handle.net/21.15107/rcub_technorep_5253 .

Barjaktarević, Dragana, Đokić, Veljko, Stevanović, Sanja, Rakin, Marko, "Influence of the electrochemical anodization on the surface roughness of Ti-13Nb-13Zr medical alloy" in Proceedings of Balkantrib '20, 10th Intenational Conference on Tribology (2021):59-62,
https://hdl.handle.net/21.15107/rcub_technorep_5253 .

TY  - CONF
AU  - Barjaktarević, Dragana
AU  - Đokić, Veljko
AU  - Veljović, Đorđe
AU  - Rakin, Marko
PY  - 2021
UR  - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5257
PB  - Materials Research Society of Srebia
C3  - Materials Research Society of Srebia
T1  - Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy
SP  - 79
UR  - https://hdl.handle.net/21.15107/rcub_technorep_5257
ER  - 

@conference{
author = "Barjaktarević, Dragana and Đokić, Veljko and Veljović, Đorđe and Rakin, Marko",
year = "2021",
publisher = "Materials Research Society of Srebia",
journal = "Materials Research Society of Srebia",
title = "Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy",
pages = "79",
url = "https://hdl.handle.net/21.15107/rcub_technorep_5257"
}

Barjaktarević, D., Đokić, V., Veljović, Đ.,& Rakin, M.. (2021). Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy. in Materials Research Society of Srebia
Materials Research Society of Srebia., 79.
https://hdl.handle.net/21.15107/rcub_technorep_5257

Barjaktarević D, Đokić V, Veljović Đ, Rakin M. Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy. in Materials Research Society of Srebia. 2021;:79.
https://hdl.handle.net/21.15107/rcub_technorep_5257 .

Barjaktarević, Dragana, Đokić, Veljko, Veljović, Đorđe, Rakin, Marko, "Morphology and mechanical properties of the nanotubular oxide coating formed on the ultrafine-grained Ti-13Nb-13Zr alloy" in Materials Research Society of Srebia (2021):79,
https://hdl.handle.net/21.15107/rcub_technorep_5257 .