Surface Structure and Dynamics of Functional Block Copolymer

采用阴离子活性聚合的方法合成了聚2，3-甲基丙烯酸二羟丙酯(PDIMA)-b-聚苯乙烯、PDIMA-b-聚(4-辛基苯乙烯)和PDIMA-b-聚异戊二烯等亲水-疏水嵌段共聚物。PDIMA的重量百分比在50%左右。用3%DMF或THF/甲醇溶液浇铸的嵌段共聚物样品，用透射电子显微镜、XPS和接触角测量对其表面结构进行了表征。干样和湿样分别固定并用OsO4蒸气溶液染色。将包埋在环氧树脂中的样品切割成超薄切片。XPS和CA测量的样品是通过旋涂在玻璃盘上制备的。薄膜在不同条件下处理后，经过铸态、水中浸泡、水浸泡后在空气中100℃的ﾟ℃热处理，测量了水的CA，对铸态薄膜的透射电子显微镜观察表明，薄膜的最外表面完全覆盖了聚苯乙烯层。在水中浸泡30min后，聚苯乙烯的表层完全消失，形成亲水性表面。在PDIMA-b-聚异戊二烯的情况下，也观察到薄膜内部的水化形态。X射线光电子能谱测量结果与透射电子显微镜观察结果一致。PDIMA-b-聚苯乙烯薄膜的接触角测量成功，而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-聚合物界面的表面结构快速重排造成的。

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.