光响应“线性-超支化”超分子嵌段共聚物的制备及其对金表面的可逆亲疏水修饰  

An Amphiphilic Linear-hyperbranched Supramolecular Block Copolymer and Its Application in Rendering Phototuning Wettability to Gold Surface

作　　者：江文峰[1] 陈建新[1] 吁松瑞[1] 周永丰[1] 颜德岳[1] 

机构地区：[1]上海交通大学化学化工学院,上海200240

出　　处：《高分子学报》2014年第10期1398-1407,共10页Acta Polymerica Sinica

基　　金：国家重点基础研究发展计划(973计划;项目号2013CB834506);国家自然科学基金重点项目(项目号91127047);国家自然科学基金杰出青年基金(基金号21225420)资助项目

摘　　要：报道了一类新型的α-ωn型"线性-超支化"超分子嵌段共聚物.分别通过可控阴离子开环多支化聚合方法(ROMBP)和可逆加成-断裂链转移聚合方法(RAFT)合成了含有一个β-环糊精基团的亲水超支化缩水甘油醚(CD-g-HPG)和含有一个偶氮苯基团的疏水线性聚甲基丙烯酸甲酯(PMMA-AZO).两者可以通过β-环糊精和偶氮苯基团之间的主客体识别作用形成两亲性线性-超支化超分子嵌段共聚物PMMA-b-HPG.由于线性PMMA-AZO残留有RAFT聚合时链转移剂中的三硫代酯结构,超分子聚合物PMMA-b-HPG可以通过三硫代酯与金形成的硫-金键(S-Au)对金表面进行修饰形成自组装单分子层(SAM).修饰后的金表面呈现出光控的可逆亲疏水性能.在紫外光下,由于β-环糊精/偶氮苯之间的主客体识别作用被破坏,亲水的CD-g-HPG从表面脱离,表面变为疏水;在可见光下,如果重新将金片浸泡在CD-g-HPG溶液中,金表面的亲水性可以恢复.Herein,the synthesis of an α-ωn＂linear-hyperbranched＂supramolecular block copolymer was reported. First,a linear polymer PMMA-AZO composed of poly（ methyl methacrylate） with an azobenzene group at the end was synthesized via reversible addition-fragmentation chain transfer（RAFT） polymerization.Secondly,a hyperbranched polymer CD-g-HPG composed of hyperbranched polyglycerol with a β-cyclodextrin group at the focal point was synthesized by ring-opening multibranching polymerization（ ROMBP）. Then,the linear PMMA-AZO and hyperbranched CD-g-HPG were conjugated together through the specific CD /AZO host-guest interactions,leading to the formation of amphiphilic linear-hyperbranched supramolecular block copolymer PMMA-b-HPG. The supramolecular polymer of PMMA-b-HPG can be grafted onto gold surface to form self-assembled monolayer through S—Au bond generated from the α end of trithiocarbonate group,which is introduced into PMMA-AZO by chain transfer agent used in RAFT polymerization. As a result,the modified surface exhibits a hydrophilic feature. When exposed to UV light,however,the hydrophilic CD-g-HPG polymers are dropped off from the surface because of the dissociation of AZO /CD complex,and then the surface turns into hydrophobic. Further immersing the gold surface into CD-g-HPG solution,a hydrophilic surface can be restored. In this way,a modified gold surface which can be tuned reversibly between hydrophilic and hydrophobic under light stimuli was prepared.

关 键 词：超分子嵌段共聚物 线性-树形 主客体相互作用 表面修饰 亲疏水转变 

分 类 号：O631.1[理学—高分子化学]