Interaction of the Polyimide Precursors PMDA and m-PDA with Ni(110). Revision.

摘要

X-ray Photoelectron Spectroscopy (XPS) and High Resolution Electron Energy Loss Spectroscopy (HREELS) have been used to study the adsorption of polyimide precursor molecules on Ni(110). PMDA (1,2,4,5-benzenetetracarboxylic anhydride) and m-PDA (1,3-phenylenediamine) were vapor deposited in vacuo at substrate temperatures of between 150 and 300K. Both m-PDA and PMDA adsorb at 300 K without major fragmentation. For m-PDA, absorption to the surface occurs via its nitrogen atoms. HREELS results suggest that significant deprotonation of the amine groups occurs and that the plane of the aromatic ring is inclined away from the surface normal. For PMDA, the primary chemical interaction with the Ni is through at least one of the anhydride oxygens, and the plane of the aromatic ring is aligned close to the surface normal. Therefore, adhesion to the surface is through one anhydride unit only. Keywords: Pyromellitic dianhydride; Phenylenediamine; Ni (110); Adsorption; Polyimides; X-ray photoelectron spectroscopy; Adhesion; High resolution electron energy loss spectroscopy; Nickel. (kt)