Preparation of durable hydrophobic surface using sol-gel method on cellulosic fabric

A low temperature process of superhydrophobic finishing of cotton fabric has been developed by sol gel method. Cellulose fabric was first coated with silica sol and butane tetracarboxylic acid (BTCA) as the acidic catalyst. The silica coated fabric was then padded with hydrolyzed alkyl silane afterwards obtaining low surface energy. Water contact angle was used to characterize superhydrophobicity. Scanning electron microscopy was used to see the surface of coated fabrics. Contact angle (CA) reached to ۱۵۸ degree and with washing CA decreased slightly. BTCA formed the ester bonds between cotton fabric and silica sol and improved the durability of superhydrophobicity.