HIGH-RESOLUTION ELECTRON-ENERGY-LOSS SPECTROSCOPY INVESTIGATION OF MOLECULAR-CONFORMATION AT THE SURFACE OF POLY(AMINO ACID)S FILMS

Electron-induced vibrational spectra of four poly(amino acid)s-poly-al anine, poly-leucine, poly-methionine, and poly(benzyl-aspartate)-have been recorded. After discussing the surface sensitivity of the techniq ue and the excitation mechanisms of the molecular vibrations, it is co ncluded that high resolution electron energy loss spectroscopy (HREELS ) spectra are dominated by vibrational bands fingerprinting the polyme r sidechains. From these observations, suggestions are made on the mol ecular conformation at the surface of these poly(amino acid)s films.