High and long-lasting antifogging performance of silane based hydrophilic polymer coating

Abstract

The inevitable presence of fog causes a loss of light transmission in optical materials and leads to many unacceptable and serious consequences. A promising strategy for avoiding fog is to modulate the wettability of the material surface and further change the formed way of droplets. Although many works achieved high antifogging coatings, they are lack of the long-lasting antifogging at varied conditions. In this work, a high adhesion strength and persistent antifogging capability hydrophilic coating is obtained by utilizing silane coupling agents containing double bonds such as triethoxyvinylsilane (A151) and 3-(trimethoxysilyl)propyl methacrylate (KH570) with 2-acrylamido-2-methylpropanesulfonic acid (AMPS) and then compositing with poly(vinyl alcohol) (PVA). The coating composed of A151 has a relatively uniform and flat surface structure, due to weaker hydrolysis ability of A151 promoted the smooth condensation speed, compared to KH570. Thanks to the hydrophilic and hydrophobic balance properties of the A151-modulated coating network, the resultant coating exhibits good antifogging performance in the range of 0 °C to 90 °C, which keeps a light transmission of about 85 %. Surprisingly, the coating shows excellent adhesion (350–700 kPa) to the substrate, which is significantly better than other conventional hydrophilic antifogging coatings, and the hydrophilic and hydrophobic modulation capability and the enhanced interfacial adhesion of A151 segments provide the basis of the coating for long-lasting antifogging, which would open up a new way of durable hydrophilic antifogging coatings.