Tuning Photocatalytic Activity and Decomposition Properties of Poly(Polyethylene Glycol Diacrylate-co-Hydroxyethyl Methacrylate)/TiO2 Composite Hydrogel

Abstract

We have synthesized TiO2-loaded porous polyethylene glycol diacrylate-co-hydroxyethyl methacrylate (poly(PEGDA-co-HEMA)) hydrogel composites having tunable photocatalytic properties with structural decomposition. TiO2 was loaded over hydrogels by impregnation of titanium oxobutyrate (Ti(OBu)(4)), peptized at room temperature that resulted poly(PEGDA-co-HEMA)/TiO2 composites. Pore morphology, crystalline structure and TiO2 content of the hydrogels/composites were examined using SEM, XRD and TGA analyses. Structural decomposition rate of the composite hydrogels and model contaminant (methyl orange) was performed under simulated sun light. Suitable pore size, morphology and higher PEGDA/HEMA ratio in the formulation increased the structural decomposition rate of the polymer that works as a TiO2 template. As the template breaks out, it leaves behind a porous TiO2 skeleton - thus accelerates the photocatalytic activity. Although the TiO2 template did not formed at lower PEGDA/HEMA ratio and lower molecular weight of PEGDA, decomposition rate of the composite slowed down (10 % in 108 h). The prepared hydrogels can be used in the skin care & engineering and waste water treatments.