Tunable Wettability and Rewritable Wettability-Gradient in Self-Cleaning Composites Containing Nanoscale Photocatalysts

Abstract

The photo induced properties of self-cleaning materials can be attributed to the synergy of two fundamental photochemical phenomena, oxidation-reduction reaction of adsorbed substances and photo induced superhydrophilicity, which occur on the surface of photo catalysts. The photo-induced properties make these materials able to mimic the tunable wettability of the Nepenthes-Rafflesiana leaf and tune their wettability while decomposing the air pollution. In this study the effects of UV radiation and dark storage on reversibility of the surface wettability in cement-based composites containing tin oxide nanoparticles, were investigated. In addition the self-cleaning properties of these composites were determined by measuring the decomposition of Methylene blue (MB).

Soft Functionally Gradient Materials and Structures – Natural and Manmade: A Review

“…[238][239][240][241][242] Zhang et al prepared an in-plane wettability gradient through the gradual immersion of a gold substrate into a hydrophobic thiol solution for different chemisorption times to produce a gradual transition from hydrophobicity to hydrophilicity. [233] Other methods of reported surface modification included UV irradiation, [238,243] electrical discharge, [239,242,244] and plasma irradiation [240,244,245] to produce WGMs by selectively modifying the surface chemistry of the substrate. Surface modification methods based on gradient surface patterning or shape gradient [236,246,247] have also been reported.…”