Fabrication of transparent superhydrophobic porous silica coating for self-cleaning and anti-fogging

Transparent coatings with self-cleaning and anti-fogging properties have received significant attention for their potential applications. In this paper, highly transparent porous silica coatings were fabricated on glass substrate through layer-by-layer (LBL) assembly of raspberry-like [email protected] ([email protected]2) microparticles followed by calcination at high temperature. The as prepared coatings showed superhydrophilic property while displayed superhydrophobicity after chemical vapor deposition with low surface energy material. After two assembly cycles, the superhydrophobic porous silica coating had a water contact angle as high as 159°±2° with a sliding angle of 7°±1.5° and a transmittance of 85%. It is demonstrated that the number of assembly cycles affected the transmittance and wettability of porous silica coatings. In addition, the anti-fogging properties of the transparent superhydrophilic and superhydrophobic surfaces were investigated, presenting totally different fogging behavior.