Transparent hydrophobic and superhydrophobic coatings fabricated using polyamide 12–SiO2 nanocomposite

TLDR: In this paper, the authors used polyamide 12-SiO2 nanocomposite (NC) on glass substrates by the spin-coating method and showed that the transformation from hydrophobic to super-hydrophobic is achieved with increase in roughness, which increases with SiO2 content.

Abstract: Optically transparent hydrophobic and superhydrophobic coatings have been prepared using polyamide 12–SiO2 nanocomposite (NC) on glass substrates by the spin-coating method. The coatings have been optimized for their hydrophobicity and transparency. The transformation from hydrophobic to superhydrophobic is achieved with increase in roughness (Ra) which increases with SiO2 content. These coatings are highly transparent in the entire visible region (400–800 nm). The influence of layer thickness on water contact angle (WCA) and optical transmittance of the coatings has been studied. Field emission scanning electron micrograph (FESEM) shows the presence of SiO2 nanoparticles covered with polyamide homogenously on the surface and the particles are aggregated to form a rough structure. X-ray diffraction (XRD) patterns show that the polyamide losses its crystalline structure in the composite. The preparation procedure reported here is simple and eco-friendly. The dual nature of the coatings, that is, high transparency and superhydrophobicity in the entire visible region suggests for its potential usage in self-cleanings, wind screen and optoelectronic applications. Copyright © 2016 John Wiley & Sons, Ltd.