Model Based on the River Meander Curve for Simulating the Adhesion of Cross-Linked Polymers to Rough Surfaces

The synergistic mechanisms of chemical interactions and mechanical interlocking in polymer-inorganic material adhesions are important; however, separating and evaluating these mechanisms is challenging. Therefore, in this study, a surface model inspired by river meander curves-a type of mathematical curve-was constructed to perform coarse-grained molecular dynamics (CGMD) simulations of cross-linked polymers adhering to channel-patterned surfaces with cooperatively adhesive forces originating from nonbonding pair interaction and surface morphology. A single-parameter river meander curve describes the flat, triangular, rectangular, and overhanging surfaces that have been observed on actual silica surfaces by electron microscopy. To systematically investigate the fracture behavior of polymers confined between two substrates being pulled apart, CGMD simulations were performed under quasi-two-dimensional periodic boundary conditions. The polymer-substrate interactions determined the fracture behavior (cohesive or interfacial). In addition, remarkable mechanical adhesion behavior was observed as anchoring effects in substrates with an overhanging shape while maintaining the temperature below the glass transition temperature of the polymer. This surface model capably distinguishes the adhesion-related factors of soft adhesive materials-nonbonding pair interactions and mechanical interlocking.