Higher UV-shielding ability and lower photocatalytic activity of TiO2@SiO2/APTES and its excellent performance in enhancing the photostability of poly(p-phenylene sulfide)

Abstract

U–TiO₂ is successfully coated with SiO₂ and subsequently well modified by APTES, and the core–shell structure exists on TiO₂@SiO₂ and TiO₂@SiO₂/APTES, which greatly reduces aggregation of the TiO₂ nanoparticles. The photocatalytic activities of U–TiO₂, TiO₂@SiO₂, and TiO₂@SiO₂/APTES are evaluated using MB decomposition. Nearly 50% of the MB is degraded after 15 min in the presence of the U–TiO₂ under UV radiation (300 W), and only 17.44% and 4.18% of the MB is degraded in the presence of the TiO₂@SiO₂-0.6 and TiO₂@SiO₂/APTES-1. However, TiO₂@SiO₂/APTES-0.6 and TiO₂@SiO₂-0.2 exhibit excellent UV absorbance capacities, and the TiO₂@SiO₂/APTES-0.6 achieves 80% of the UV-shielding ability of U–TiO₂. Poly(p-phenylene sulfide) (PPS) is an easily photodegraded material and TiO₂/PPS is more seriously photodegraded than PPS, however, the TiO₂@SiO₂/APTES nanoparticles can effectively protect the PPS from UV degradation, owing to their lower photocatalytic activities, higher UV-shielding abilities and easy dispersion in the PPS matrix. The breaking strength retention rate of the 1 wt% TiO₂@SiO₂/APTES/PPS film shows a maximum increase of 38.26%, and the breaking elongation retention rate increased by 41.64% at 2 wt% TiO₂@SiO₂/APTES loading. These results reveal that the incorporation of the TiO₂@SiO₂/APTES nanoparticles into the PPS matrix imparts excellent anti-UV properties to the PPS matrix, leading to a mechanical performance improvement.