Synthesis and Characterization of Superhydrophobic Alumina-Silane Sol-gel Coating

Abstract

Superhydrophobic surfaces have attracted significant research interest because of their use for the design of water-repellent and self-cleaning coatings. A superhydrophobic surface can be created by modifying a rough surface with a low surface energy material through a sol-gel coating technique. Adjusting the amount of precursor and the low surface energy material can optimise the hydrophobicity of the coating. In this work, different ratios (4:1, 3:2, 1:1 and 2:3) of silane: alumina coatings were synthesised and applied on glass substrates through the sol-gel method. Characterisation of the coated samples showed that volume ratios of silane sol and alumina sol in sol-gel coating affected the superhydrophobicity of the coated glass substrate. The solution of alumina sol and silane sol with a ratio of 4:1 produced superhydrophobic films with a contact angle for water larger than 150 , and FESEM images showed very intense roughness compared to the other ratios.