Wetting behavior of high energy electron irradiated porous superhydrophobic silica films

The nature of adhesive forces between water and hydrophobic materials has been a subject of great interest. The influence of high energy electron irradiation (7 MeV) on wetting behavior of superhydrophobic silica films has been investigated. The results of surface morphological study suggest that the porous morphology of pristine (non-irradiated) silica film was changed to compact morphology after electron irradiation (of energy 7 MeV). The experiments showed that a gradual decrease in static water contact angle (SWCA); whereas an abrupt increase in water sliding angle (WSA) of irradiated silica film. The water droplets easily roll off on the pristine silica films, whereas the water droplet does not slide on the irradiated silica film surface even when the surface is tilted vertically or turned upside down. We characterized the pristine and irradiated silica films by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), atomic force microscopy (AFM), and static and dynamic water contact angle measurements.