UV durable superhydrophobic PLA films with UV shielding properties

Abstract

The ZnO/SiO2 core/shell particles were fabricated through layer-by-layer deposition with poly(sodium 4-styrenesulfonate) (PSS) and poly(diallyldimethylammonium chloride) (PDDA), followed by the coating of ZnO particles with a shell of SiO2. Polylactide (PLA) films were prepared by compression molding and immersed into a weak alkali solution to induce a strong interaction between the films and the composite particles. To induce surface roughness, the PLA films were coated with the ZnO/SiO2 core/shell particles. A superhydrophobic surface with ultraviolet (UV) shielding characteristic was successfully developed with hexadecyltrimethoxysilane (HDTMS). The incorporation of ZnO onto the PLA films imparted the film surface with UV-blocking property, while the coating of ZnO particles with a SiO2 shell disturbed the photocatalytic degradation of HDTMS by ZnO, making the PLA film maintain the stable superhydrophobic surface with good UV-shielding properties.