Physical, optical and mechanical properties of BNNSs/PVB coatings under UV irradiation

Abstract

This study reports the effect of ultraviolet (UV) irradiation on the structural, optical and mechanical properties of glass coated with boron nitride (BN) nanosheets (BNNSs)/polyvinyl butyral (PVB) multilayers. The BNNSs were prepared by using the liquid exfoliation method, and BNNSs/PVB multilayer films were produced using dip-coating. The UV irradiation tests showed that the transmittance of the glass coated with BNNSs/PVB multilayer film reduced with increasing UV irradiation time. After 170 h of UV exposure, the transmittance decreased by 2·30–13·23% because of the structural changes that had occurred in the film. It has been found that as the number of BNNS dipping cycles was increased, the transmittance dropped more evidently. UV irradiation enhanced the UV-absorbent properties of the BNNSs/PVB films. The flexural strength and modulus of the BNNSs/PVB-coated glass samples were found to increase until 25–50 h of UV exposure and then decrease with a longer UV irradiation time, ascribed to the degradation of the PVB layer. This study indicates that BNNSs/PVB multilayer films can be a great candidate for UV protection with high transparency in the visible region.