Surface Structure and Dynamics of Functional Block Copolymer

采用阴离子活性聚合法制备了亲疏水嵌段共聚物聚（2,3-二羟丙基甲基丙烯酸酯）(PDIMA)-b-聚苯乙烯、PDIMA-b-聚（4-辛基苯乙烯）和PDIMA-b-聚异戊二烯。PDIMA的重量%在50%左右。通过透射电子显微镜（TEM）观察、XPS和接触角（CA）测量对嵌段共聚物的表面结构进行了研究。用3% DMF或THF/甲醇溶液铸造TEM观察样品。干法和湿法样品分别用OsO4蒸汽溶液固定和染色。将包埋在环氧树脂中的样品切割成超薄切片。用于XPS和CA测量的样品是通过在玻璃圆盘上旋转涂层制备的。通过对薄膜进行浇铸、水浸泡、水浸泡后在100^ C空气中退火等不同条件下的处理，测定了水的CA。对pdima -b-聚苯乙烯铸膜的透射电镜观察表明，pdima -b-聚苯乙烯铸膜的最外层完全被聚苯乙烯层覆盖。在水中浸泡30min后，聚苯乙烯表层完全消失，形成亲水表面。在pdima -b-聚异戊二烯的情况下，薄膜内部也观察到水合形态。XPS测量结果与TEM观察结果一致。pdima -b-聚苯乙烯薄膜的接触角测量成功，但pdima -b-聚（4-辛基苯乙烯）和pdima -b-聚异戊二烯薄膜的接触角测量不成功。这是由于水-聚合物界面表面结构的快速重排。

Hydrophilic-hydrophobic block copolymers, poly(2,3-dihydroxypropyl methacrylate) (PDIMA)-b-polystyrene, PDIMA-b-poly(4-octylstyrene), and PDIMA-b-polyisoprene, have been synthesized by anionic living polymerization. The weight % of PDIMA was around 50 %. The surface structures of the block copolymers were investigated by transmission electron miroscopic(TEM) observation, XPS and contact angle(CA) measurements.The specimens for TEM observation were cast from 3% DMF or THF/methanol solution. The dry and wet samples were fixed and stained with OsO4 vapor solution, respectively. The sample embedded in epoxy resin were cut into the ultra thin sections. The specimens for XPS and CA measurements were prepared by spin-coating onto a glass disk. After treatment of the film under various conditions, as-cast, soaking in water, and annealing at 100^ﾟC in air after soaking in water, CA of water was measured.TEM observation of the as-cast film of PDIMA-b-polystyrene showed that the outermost surface was completely covered with polystyrene layer. After soaking in water for 30 min, the top layer of polystyrene was completely disappeared to lead hydrophilic surface. In the case of PDIMA-b-polyisoprene, the hydrated morphology was also observed inside of the film. The XPS measurement gave the consistent results with those of the TEM observation. The contact angle measurement was successful for the PDIMA-b-polystyrene film, but not for the PDIMA-b-poly(4-octylstyrene) and PDIMA-b-polyisoprene films. This is because of rapid rearrangement of the surface structure at the water-polymer interface.