Class-II-type nanosilica-epoxy hybrid coating with high moisture barrier performance and mechanical robustness

We report the development of a class-II-type hybrid coating (NS-EP hybrid) composed of surface-modified nanosilica (NS) as the filler and a thermo-curable epoxy polymer (EP) as the matrix. NS is synthesized using a hydrolytic sol-gel process; its hydroxyl surface is rendered cross-linkable using glycidyl ligands to ensure homogeneous dispersion and optimal hybridization with the EP matrix. The NS-EP hybrid shows high optical transparency, enhanced mechanical properties, and improved moisture barrier performance. Further, we discuss the physical properties of the hybrid with respect to the NS content. To study the applicability of the hybrid as a high-performance barrier material in practical applications, an actual OLED device is encapsulated using the hybrid.