Effect of surface composition and atomic roughness on interfacial adhesion between polyester and amorphous carbon

This theoretical study examines the adhesion of amorphous carbon to functionalized polyester surfaces. Several modifications to the polyester surface have been investigated including the addition of hydroxyl, carboxyl, or fluorine substiments at varying surface concentrations. Initially, the polyesters were artificially held rigid, and the surface modification not only imparted chemical changes to the polymer surface but also accentuated its atomic scale roughness. Under this rigid regime, low concentrations of surface modifiers have been shown to lead to the greatest reduction in adhesion with amorphous carbon, and increasing the level of modification does not provide further advantages in the reduction of adhesion, due to saturation. The effects of surface reorganization were also investigated and have been shown to be strongly dependent on the structure of the carbon surface, the chemical type, and surface density of modifiers. The surface modifiers reorganize during relaxation, which leads to significant differences in their effects on adhesion.