The robust superhydrophobic SiO2/Diatomite/PDMS/KH-570/Me-MQ composite coating for self-cleaning application of building surface

Abstract

A kind of SiO2/Diatomite/PDMS/KH-570/Me-MQ composite superhydrophobic self-cleaning building coating material was successfully synthesised at room temperature. Without any subsequent heat treatment process, the coating can be prepared by spraying or brushing on smooth internal wall and rough external wall of building with a water contact angle (WCA) larger than 160° and a sliding angle (SA) less than 1.5°. The coating can maintain excellent superhydrophobic and self-cleaning properties after various tests including sand impact, sandpaper abrasion, acid/alkali solution immersion, water impact and outdoor weatherability test. Moreover, after 0.5 h impact by pH 4 methyl blue solution, the superhydrophobic performance of the coating still keep excellent and indicates that the coating can withstand a certain degree of acid rain impact. Futhermore, the coating also can be brushed or sprayed on various smooth, rough, hard or soft substrates, and they all can exhibit excellent superhydrophobic performance. It is reasonable to believe that such superhydrophobic coating material has a good practical application potential in building self-cleaning and antifouling.