Fabrication of PS-TiO2 hybrid via mini-emulsion polymerization: Study the effect of crosslink on the photocatalytic properties of the hybrid

Abstract

In this study, a polystyrene (PS)/nano-TiO₂ hybrid was prepared by a mini-emulsion polymerization process to improve the photocatalytic properties when the crosslinking agent was added. N, N'-methylenebis (acrylamide) (MbA) was used as a crosslinking agent. The effect of a crosslinking agent on the photocatalytic properties was studied. The diameter, morphology, and photocatalytic properties of the samples were characterized and discussed. The methylene blue discoloration was monitored at 660 nm by a spectrophotometer. The result showed that the L* value from the Hunter color scale for 7 wt% TiO₂-PS/0.25 wt% MbA was highest at 73.73. It was noticed that the 7 wt% TiO₂ - PS/0.25 wt% MbA hybrid gave the highest photocatalytic properties. The FE-SEM confirmed the well-defined structure with a spherical shape and network formation to improve the photocatalytic properties. The diameter and morphology of the PS/TiO₂ hybrid were in the range of 76 nm to 95 nm by using a field emission scanning electron microscope (FE-SEM). The particle size of the 1 wt% TiO₂ - PS/0.25 wt% MbA was 76 nm, which was smaller than that of the pristine PS of 88 nm. The particle size of the 7 wt% TiO₂ – PS/0.25 wt% MbA hybrid was increased by 25%. The HR-TEM image of the PS/TiO₂ hybrid was studied to confirm the encapsulation of TiO₂ particles in the hybrid. The FFT image of PS/MbA/TiO₂ 7 wt% demonstrated the crystalline structure of TiO₂ (dot) and the amorphous structure of PS (ring). FT-IR spectroscopy confirmed the presence of the Ti-O functional group in the PS hybrid spectra. It was noticed that the TiO₂ particles were successfully encapsulated in the PS/TiO₂ hybrid.