Preparation of stable, transparent superhydrophobic film via one step one pot sol-gel method

Herein, we report a single step and a one pot by using spin coating method for the preparation of optically transparent superhydrophobic TEOS-silica composite films. Silica sols were prepared by keeping the molar ratio of TEOS/CH3OH/H2O (0.1 M NH4F) constant at 1:33.15:6.06, respectively. Increasing the silica content of the coating solution resulted in decreasing the transparency of the composite films from 93 to 84% (in references to 93% transmission defined by a plain glass substrate). The static water and hexadecane contact angle of transparent surfaces were found to vary between 65A degrees and 170A degrees (sliding angle < 3A degrees) and 45A degrees to 5A degrees (sliding angle = 15A degrees) depending on the silica content. The stability of the surface remained nearly constant for several months under stored at ambient conditions. The mechanical stability of the prepared of TEOS-silica composite was tested by scratching and adhesive tape test. For the chemical test applications, NaOH, HCl, and H2SO4 were used for the TEOS-silica composite films.