Construction of Infared-Excitation Nano-meter Scale Spectroscopic Surface Analyzer and Its Application to Polymer-Water Interfaces

用振动光谱技术研究了两性离子聚合物聚CMB(CMB，羧基甜菜碱单体)和CMB与甲基丙烯酸正丁酯无规共聚物(Poly，CMB-r-BMA)在水溶液和薄膜中的结构和氢键。水溶性两性离子聚合物的氢键因单体残基(N&lt；corr&gt；值)的存在而崩溃的数目远小于普通聚电解质，而接近于非离子水溶性聚合物的氢键数目。此外，与聚甲基丙烯酸甲酯(PMMA)和聚甲基丙烯酸丁酯(PBMA)等聚合物膜中水的O-H伸展带的剧烈变化相反，大BMA含量的两性共聚物膜中的水的O-H伸缩带与自由水的O-H伸展带相似。原子力显微镜(AFM)的观察证实了两性离子共聚物薄膜对聚合物薄膜中水分的吸附和解吸的响应性。血小板与两性离子共聚物膜(如聚(CMB-r-BMA))的粘附性远低于与PMMA和PBMA的粘附性。随着CMB残留量的增加，人血小板附着在聚(CMB-r-BMA)膜上的数量急剧减少，然后逐渐增加，这可能是由于膜表面粗糙度的增加所致。这些结果表明，具有两性离子结构的单体残基不会显著干扰水分子在水溶液和薄膜体系中的氢键，从而使两性离子聚合物具有良好的血液相容性。

The structure and hydrogen bonding of water in the vicinity of zwitterionic polymers such as PolyCMB (CMB, carboxybetaine monomer) and a random copolymer of CMB and n-butyl methacrylate, Poly(CMB-r-BMA), were analyzed in their aqueous solutions and thin film using vibrational spectroscopy. The number of hydrogen bonding collapsed by the presence of one monomer residue (N_<corr> value) of water-soluble zwitterionic polymers were much smaller than those for ordinary polyelectrolytes and close to those for nonionic water-soluble polymers. Furthermore, the O-H stretching band of vibrational spectra for the water incorporated in the film of zwitterionic copolymer with a large BMA content was similar to that for free water, which is in contrast with the drastic change in the O-H stretching band of water incorporated in polymer films such as poly(methyl methacrylate) (PMMA) and poly(n-butyl methacrylate) (PBMA). The observation with an atomic force microscope (AFM) confirmed the responsiveness of zwitterionic copolymer films to the sorption and desorption of water from the polymer films. The adhesion of platelets to zwitterionic copolymer films (Poly(CMB-r-BMA), for example) was much less than that to PMMA and PBMA. With an increase in the content of CMB residue, the number of human platelets adhered to the Poly(CMB-r-BMA) film drastically decreased and then gradually increased, probably due to the increase in the roughness of the film surface. These results suggest that the monomer residues with a zwitterionic structure do not significantly disturb the hydrogen bonding between water molecules in both aqueous solution and thin film systems, resulting in the excellent blood-compatibility of the zwitterionic polymers.