两亲性PS-b-PEG嵌段共聚物刷的合成及响应行为

利用原子转移自由基聚合(ATRP)和点击化学(Click)反应, 在硅基底上制备了聚苯乙烯-b-聚乙二醇(PS-b-PEG)两亲性嵌段共聚物刷. 首先, 利用ATRP方法在表面改性的硅片引发苯乙烯单体(St)的聚合, 得到PS-Br均聚刷, 然后通过叠氮化钠(NaN₃)将均聚刷末端功能化为PS-N₃, 再与炔基聚乙二醇甲醚(Alkynyl-PEG)发生Click反应, 得到PS-b-PEG嵌段共聚物刷. 通过X射线光电子能谱(XPS)和接触角测量仪表征了聚合物刷的表面化学组成和表面亲疏水性质, 证明在硅基底上接枝了嵌段共聚物刷. 用原子力显微镜(AFM)观察了PS-b-PEG嵌段共聚物刷在不同溶剂处理后的形态结构变化, 研究了其响应行为.

Synthesis and Responsive Behavior of Amphiphilic PS-b-PEG Diblock Copolymer Brushes

Polystyrene-b-polyethylene glycol(PS-b-PEG) diblock copolymer brushes on a silicon wafer were synthesized via the combination of atom transfer radical polymerization(ATRP) and Click chemistry reaction. The ATRP initiator was grafted to silicon wafer. Then, polystyrene was grafted to the substrates through ATRP technique. After azidation with NaN3, the Si/SiO2/PS-Br brushes were transformed to Si/SiO2/PS-N3 with azide groups at the ends. The synthesis of PS-b-PEG brushes was then achieved via the click reaction of the obtained Si/SiO2/PS-N3 and an excess of alkynyl-PEG. The chemical compositions and the surface properties of the as-prepared PS-b-PEG brushes were detected via X-ray photoelectron spectroscopy(XPS), atomic force microscopy(AFM), ellipsometry, and water contact angle techniques. The responsive behavior of diblock copolymer brushes treated under different solvents was also discussed.