Selectively controlling the surface adhesion of highly transparent polymer thin films through thermoactivated cavitation of interface-assembled gas-blasting nanocapsules

Abstract

Transparent polymer thin films have received increasing attention as functional optical materials for sunlight control and are widely used in applications ranging from photovoltaic solar cells to flexible display devices. Because various types of film defects may occur during the thin film process, a clean separation technology for the recovery of valuable core components is crucial for sustainable engineering but remains challenging. Herein, we report an effective and scalable method for selectively controlling the surface adhesion of highly transparent polymer thin films using the thermoactivated cavitation of interface-assembled gas-blasting nanocapsules. The synthesized nanocapsules, comprising poly(acrylonitrile-co-methyl methacrylate) as a polymer shell layer and benzenesulfonyl hydrazide as a gas-generating core material, were uniformly mixed with ultraviolet-curable resins and applied as a surface adhesion-controllable layer between the substrate and transparent polymer thin film. This interface-assembled gas-blasting nanocapsule layer can form N2-gas microbubbles at the interface between the substrate and thin film upon heating, enabling the large-area and flawless separation of transparent thin films with a tremendous reduction in the surface adhesion strength. Furthermore, the interfacial adhesion of highly transparent thin films was effectively controlled by optimizing the heat treatment process without affecting their optical transparency or intrinsic adhesive properties.