SiO2-Based Nanostructured Superhydrophobic Film with High Optical Transmittance

Superhydrophobic and transparent films would be very useful in optoelectronic applications where non-wetting is desired. Herein, hexamethyldisilazane was used for functionalization of fumed SiO2 nanoparticles via silylation derivatization reaction. Modified fumed SiO2 nanoparticle dispersion was used for fabrication of SiO2-based nanostructured film via drop-casting method. This film exhibited a combination of high optical transmittance in the visible spectrum portion and superhydrophobicity (163 degrees +/- 1 degrees and hysteresis as low as similar to 2 degrees). This was possible to achieve due to the submicrometer-scale roughness (R-q = 252.7 nm) and branched network structure of the film surface with convenient surface chemistry of hydrophobic methyl groups. The method reported herein is not complicated, allows for obtaining large quantities of modified SiO2 nanoparticle dispersions and can be used in combination with other deposition methods.