Fabrication of Superhydrophobic Coatings on Glass based on Poly(dimethylsiloxane) and Fumed Silica

Abstract

This study reports the preparation of superhydrophobic covalently attachedpoly(dimethylsiloxane)(PDMS)/fumed silica composite coatings on glass via spin-coating and subsequentheating. The effect of PDMS molecular weight and fumed silica type (hydrophilic and three differenthydrophobic) on the wettability and morphology were studied in detail, and the wettability and morphologyof the coatings were characterized by contact angle measurements and scanning electron microscopy(SEM). Superhydrophobic coatings which have advancing contact angles of 172-174° and contact anglehysteresis (CAH) as low as 7-8° were obtained using 4% (w/v) PDMS modified hydrophobic fumed silicaand all kinds of PDMS. The surfaces which were prepared by 4% (w/v) hydrophilic and dimethylsiloxymodified fumed silica had high advancing contact angles of 163-168°, but the CAH on these surfaces werehigher than the ones prepared using PDMS modified fumed silica. It is due to the incompatibility of thehydrophilic and dimethylsiloxy-modified fumed silica with the PDMS matrix also confirmed with the SEMresults.