Molecular structure of carboxymethyl starch in dilute aqueous sodium chloride solutions
Abstract
The dilute solution behavior of six carboxymethyl starch (CMS) samples was investigated in aqueous NaCl solutions of different concentration (0.01, 0.05, 0.1, and 0.5 M) by dynamic light scattering (DLS) at 25°C. The values of weight average molar mass, Mw, of the investigated CMS samples were in the range from 9 × 105 to 2.1 × 107 g/mol. Three of the CMS samples were obtained from corn starch and the other three from potato starch. They had different degrees of substitution, DS, ranging from 0.4 to 1.1. The translational diffusion coefficient, Dz, and hydrodynamic radius, Rh, were determined for all CMS samples in aqueous NaCl solutions of different concentrations by the DLS method. The obtained results were treated together with previous results obtained by static light scattering and viscometry, which enabled the calculation of the structure-sensitive parameter, ρ, and the dependence of Rh, radius of gyration, Rg, and viscosity radius, Rη, on molar mass. The calculated values of the... ρ parameter were independent of molar mass. The parameter ρ did not change significantly with the variation of the salt concentration in water, its values being in the range from 1.10 to 1.19. The values of exponent ni in the log-log dependence of Rg, Rh, and Rη on Mw were in the range between 0.42 and 0.47; 0.36 and 0.49; 0.42 and 0.44, respectively. These values are characteristic of branched structures of macromolecules.
Keywords:
Carboxymethyl starch / Dynamic light scattering / Static light scattering / Structure parameterSource:
Starch/Staerke, 2013, 65, 11-12, 902-911Publisher:
- Wiley-VCH Verlag
Funding / projects:
- Synthesis and characterization of novel functional polymers and polymeric nanocomposites (RS-172062)
DOI: 10.1002/star.201200225
ISSN: 0038-9056
WoS: 000327734700002
Scopus: 2-s2.0-84894327219
Institution/Community
Tehnološko-metalurški fakultetTY - JOUR AU - Stojanović, Željko AU - Jeremić, Katarina AU - Jovanović, Slobodan PY - 2013 UR - http://TechnoRep.tmf.bg.ac.rs/handle/123456789/5731 AB - The dilute solution behavior of six carboxymethyl starch (CMS) samples was investigated in aqueous NaCl solutions of different concentration (0.01, 0.05, 0.1, and 0.5 M) by dynamic light scattering (DLS) at 25°C. The values of weight average molar mass, Mw, of the investigated CMS samples were in the range from 9 × 105 to 2.1 × 107 g/mol. Three of the CMS samples were obtained from corn starch and the other three from potato starch. They had different degrees of substitution, DS, ranging from 0.4 to 1.1. The translational diffusion coefficient, Dz, and hydrodynamic radius, Rh, were determined for all CMS samples in aqueous NaCl solutions of different concentrations by the DLS method. The obtained results were treated together with previous results obtained by static light scattering and viscometry, which enabled the calculation of the structure-sensitive parameter, ρ, and the dependence of Rh, radius of gyration, Rg, and viscosity radius, Rη, on molar mass. The calculated values of the ρ parameter were independent of molar mass. The parameter ρ did not change significantly with the variation of the salt concentration in water, its values being in the range from 1.10 to 1.19. The values of exponent ni in the log-log dependence of Rg, Rh, and Rη on Mw were in the range between 0.42 and 0.47; 0.36 and 0.49; 0.42 and 0.44, respectively. These values are characteristic of branched structures of macromolecules. PB - Wiley-VCH Verlag T2 - Starch/Staerke T1 - Molecular structure of carboxymethyl starch in dilute aqueous sodium chloride solutions EP - 911 IS - 11-12 SP - 902 VL - 65 DO - 10.1002/star.201200225 ER -
@article{ author = "Stojanović, Željko and Jeremić, Katarina and Jovanović, Slobodan", year = "2013", abstract = "The dilute solution behavior of six carboxymethyl starch (CMS) samples was investigated in aqueous NaCl solutions of different concentration (0.01, 0.05, 0.1, and 0.5 M) by dynamic light scattering (DLS) at 25°C. The values of weight average molar mass, Mw, of the investigated CMS samples were in the range from 9 × 105 to 2.1 × 107 g/mol. Three of the CMS samples were obtained from corn starch and the other three from potato starch. They had different degrees of substitution, DS, ranging from 0.4 to 1.1. The translational diffusion coefficient, Dz, and hydrodynamic radius, Rh, were determined for all CMS samples in aqueous NaCl solutions of different concentrations by the DLS method. The obtained results were treated together with previous results obtained by static light scattering and viscometry, which enabled the calculation of the structure-sensitive parameter, ρ, and the dependence of Rh, radius of gyration, Rg, and viscosity radius, Rη, on molar mass. The calculated values of the ρ parameter were independent of molar mass. The parameter ρ did not change significantly with the variation of the salt concentration in water, its values being in the range from 1.10 to 1.19. The values of exponent ni in the log-log dependence of Rg, Rh, and Rη on Mw were in the range between 0.42 and 0.47; 0.36 and 0.49; 0.42 and 0.44, respectively. These values are characteristic of branched structures of macromolecules.", publisher = "Wiley-VCH Verlag", journal = "Starch/Staerke", title = "Molecular structure of carboxymethyl starch in dilute aqueous sodium chloride solutions", pages = "911-902", number = "11-12", volume = "65", doi = "10.1002/star.201200225" }
Stojanović, Ž., Jeremić, K.,& Jovanović, S.. (2013). Molecular structure of carboxymethyl starch in dilute aqueous sodium chloride solutions. in Starch/Staerke Wiley-VCH Verlag., 65(11-12), 902-911. https://doi.org/10.1002/star.201200225
Stojanović Ž, Jeremić K, Jovanović S. Molecular structure of carboxymethyl starch in dilute aqueous sodium chloride solutions. in Starch/Staerke. 2013;65(11-12):902-911. doi:10.1002/star.201200225 .
Stojanović, Željko, Jeremić, Katarina, Jovanović, Slobodan, "Molecular structure of carboxymethyl starch in dilute aqueous sodium chloride solutions" in Starch/Staerke, 65, no. 11-12 (2013):902-911, https://doi.org/10.1002/star.201200225 . .