Functionalization of PLA Aerogels with TiO2 Nanoparticles

Abstract

This study was aimed to prepare material with high porosity and photocatalytic activity by immobilization of TiO2 nanoparticles (NPs) onto poly(lactic acid) (PLA) aerogels. PLA aerogels were prepared in three steps: (1) dissolution of polymer in chloroform at 22 °C, (2) chloroform replacement with ethanol, and (3) supercritical CO2-drying at pressure 19 MPa and temperature 39 ºC. Immobilization of TiO2 NPs was performed by in situ and ex situ methods. Obtained samples were characterized using SEM, EDX, and FTIR analysis. Photocatalytic activity of developed material was tested by following decolorization of dye C.I. Acid Orange 7 in water solution. It was shown that the morphology of PLA aerogels was slightly affected by TiO2 NPs immobilization. PLA aerogels with TiO2 NPs immobilized by ex situ method sustained floatability during test period and provided a complete decolorization of dye solution after 330 minutes of illumination. High photocatalytic activity of the sample was preserved within three repeated cycles of dye decolorization.

Cilj ovog istraživanja bio je priprema materijala velike poroznosti i fotokatalitičke aktivnosti imobilizacijom nanočestica TiO2 na aerogelove poli(mlečne kiseline) (PLA). PLA aerogelovi su pripremljeni u tri koraka: (1) rastvaranje polimera u hloroformu na 22 °C, (2) zamena hloroforma etanolom i (3) natkritično sušenje upotrebom CO2 na pritisku 19 MPa i temperaturi 39 ºC. Imobilizacija TiO2 nanočestica izvedena je in situ i ex situ metodama. Dobijeni uzorci su okarakterisani pomoću SEM, EDX i FTIR analize. Fotokatalitička aktivnost razvijenog materijala ispitana je prateći obezbojavanje vodenog rastvora boje C.I. Acid Orange 7. Pokazano je da imobilizacija TiO2 nanočestica ne utiče značajno na morfologiju PLA aerogelova. PLA aerogelovi sa TiO2 nanočesticama imobilisanim ex situ metodom održavali su plutabilnost tokom isitivanja i omogućili su potpuno obezbojenje rastvora boje nakon 330 minuta osvetljenja. Velika fotokatalitička aktivnost uzorka očuvana je tokom tri ponovljena ciklusa obezbojavanja rastvora boje.