Theoretical study of metal-polyimide interfacial properties

Abstract

The aim of this work is to achieve a better understanding of metal-polyimide interfacial properties, such as bonding strength between two materials and charge transfer, and to assess the consequences for the adhesion. The effect of surface modification on adhesion is also discussed. These interfacial studies of PMDA-ODA polyimide with evaporated chromium (Cr), copper (Cu) and nickel (Ni) atoms have been performed using a self-consistent molecular dynamics method with semi-empirical quantum chemistry at the complete neglect of differential overlap level. All metals were predicted to bond strongly at six-fold rings of polyimide. Despite actual charge transfer between metal atoms and polyimide is small, the bond formation induces charge rearrangement among the polyimide atoms far from the reaction site. The adhesion of polyimide to a Ni(100) surface is predicted to be somewhat weaker than that of nickel atoms to polyimide at six-fold sites.