Rational construction of multifunctional hydrophilic coatings with sustainable anti-fogging, UV-shielding and anti-freezing abilities

Abstract

Special wettability endows surface anti-fogging performance on transparent substrates by promoting filmwise condensation via hydrophilic materials or preventing water adhesion via hydrophobic materials. However, the harsh environments associated with low temperature and mechanical loads restrict their anti-fogging persistence. In this work, a hydrophilic coating with long-lasting anti-fogging, anti-freezing, and anti-aging properties was rationally prepared by constructing a double-layer structure. The bottom layer (T coating) adopts a titanium dioxide coating obtained by hydrolysis of tetrabutyl titanate, which can act as a UV absorber and improve the UV-shielding property of the coating. The top layer (ZGS coating) is constructed of a cross-linked network structure with zein, gelatin, glucose and silica for anti-freezing and anti-fogging properties. The resulting coating (ZGST) can maintain excellent anti-fogging performance after placing in a hot fog environment (100℃) for 1 h, 300 cycles abrasion, 70 tape-peeling, 120 min ultrasonication and extended service time (261 days so for). One application of greenhouse films with anti-fogging performance was demonstrated, which can improve the status quo of agricultural film and has important significance for the field of agricultural development. It is anticipated that this work may offer valuable guidance for the preparation of anti-fogging, anti-freezing and UV resistant optical materials, which allows potential applications in vehicles, medical, agricultural or vision systems under extreme environments.