CONSTRUCTION OF INFRARED-ACTIVATED SCANNING AFM SURFACE ANALYZER AND ITS APPLICATION TO THE CHARACTERIZATION OF POLYMER THIN FILM-WATERINTERFACES.

点击翻译按钮获取中文摘要

A novel infrared-activated scanning AFM surface analyzer was constructed and characterization of polymer thin film-water interfaces using the apparatus was examined. Furthermore, the structure and hydrogen bonding of water in aqueous solution of sulfobetaine polymers were analyzed with contours of O-H stretching of polarized Raman spectra. The number of hydrogen bonding collapsed by the presence of one monomer residue (N value) for the polymers was a small positive value, and comparable to those for neutral polymers. This is in good contrast to the largely positive N values for the precursor polymer, and ordinary polyelectrolytes. The present results clearly indicate that the zwitter ionic polymers do not disturb the hydrogen-bonded network structure of water significantly, probably due to the counteraction of electrostriction effect by the proximity between the anionic and cationic groups. Moreover, the structure of water sorbed into copolymer of (2-methoxyethylacrylate) (MEA) and 2-hydroxyethylmethacrylate (HEMA) was investigated by an attenuated total reflection infrared (ATR-IR) spectroscopy. The effective hydration region around the polymer chain was estimated by the comparison of the extinction coefficient, eOH, for the water sorbed into the polymers contacting with liquid water and water vapor. The result seemed to indicate that the interaction between the primary hydration water and water molecules surrounding them around the MEA-containing polymer chain is very weak. Namely, the effective hydration region around the polymer chain is very small. Such water with the large eOH value seemed to correspond to a "cold-crystallizable" water, which has been observed by DSC as anomalous water other than intermediate and non-freezable waters.