The adhesion energy between polymer thin films and self-assembled monolayers

A superlayer test has been adapted for the measurement of the fracture energy between epoxy thin films and self-assembled monolayers (SAM's) on Au/Ti/Si substrates. The “arrest” mode of analysis has been shown to provide consistent results, particularly when relatively wide lines are used to encourage lateral decohesions. The fracture energy, Γ_i, of the interface between the monolayer and the epoxy is varied by adjusting the ratio of COOH/CH₃ terminal groups. Connections among Γ_i, the surface energies, and the inelastic deformations occurring in the epoxy are explored upon comparison with interface crack growth simulations.