A Translucent and Superhydrophobic Surface Prepared With a Sol–Gel Method Based on Alumina Nanoparticles

A translucent and superhydrophobic surface was prepared with a sol–gel method on a glass substrate. The coating solution was obtained by hydrolysis of a chelate compound of aluminum isopropoxide and ethyl acetoacetate. Then, the films were prepared by dip-coating the glass substrates and subsequent surface modification with stearic acid. Field-emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), Fourier transform infrared (FT-IR) spectroscopy, UV-Vis spectroscopy, and contact angle (CA) measurements were used for the surface characterization. It was demonstrated that the coatings comprised a roughness structure on two levels with the root mean square roughnesses (R rms) of ca. 30 and 200 nm, resulting in water static contact angle up to 168° and a small sliding angle of only 3°. The average visible light transmittance of the coatings was 62%.