Formation of superhydrophobic boehmite film on glass substrate by sol-gel method

Superhydrophobic boehmite film has been successfully prepared on a glass substrate by a sol-gel method. A chelated Aluminum-sec-butoxide (Al(OBus)3) solution, instead of aluminum hydroxide collosol, was used for the film coating. By immersing the film in boiling water, boehmite crystal was formed on a glass substrate. Subsequently, the rough surface was modified with fluoroalkylsilane (FAS). The result shows that the water droplet contact angle on the surface is 168.3°. The superwater-repellency is caused by the micro-nano structure and the low surface energy of the fluorinated surface. The reaction mechanism is proposed with the help of SEM, XRD and FT-IR analysis.