水蒸气诱导两性离子聚合物刷的构象转变  

Switching of polyzwitterion brushes by water vapor

作　　者：赵新军[1,2] 李祯[1] ZHAO Xin-Jun;LI Zhen(Xinjiang Laboratory of Phase Transitions and Microstructures of Condensed Matter Physics,Yi Li Normal University,Yining 835000,China;Laboratory of Micro-Nano Electro Biosensors and Bionic Devices,Yi Li Normal University,Yining 835000,China)

机构地区：[1]伊犁师范学院新疆凝聚态相变与微结构实验室,伊宁835000 [2]伊犁师范学院微纳电传感器技术与仿生器械实验室,伊宁835000

出　　处：《原子与分子物理学报》2018年第2期307-313,共7页Journal of Atomic and Molecular Physics

基　　金：新疆自然科学基金联合基金(2015211C298)

摘　　要：我们把Flory Huggins模型(association models)推广应用到暴露于水蒸气中的两性离子聚合物刷体系,考虑两性离子聚合物-水氢键(P-W氢键)与两性离子聚合物链间两亲离子单体-单体键合(zwitterions complex)、形成氢键与两性离子聚合物链构象的耦合特性,研究水蒸气诱导的两性离子聚合物刷构象转变的机理和相行为.研究发现,随着水蒸气浓度的增加,P-W氢键效应会使得两性离子聚合物刷溶胀;两亲离子单体-单体键合效应会导致水分子将会被排出刷外,并会导致两性离子聚合物刷塌缩.通过分析两性离子聚合物刷的相图发现,P-W氢键效应在决定两性离子聚合物刷的相行为中起到主导作用,在水蒸气增加过程中两性离子聚合物刷将会单调溶胀.基于本文的分析,可以预言,由于P-W氢键效应,两性离子聚合物刷可以吸附水蒸气,当两性离子聚合物链接枝密度足够高时,两性离子聚合物刷内的水分子将会被排出,并会形成两亲离子单体-单体键合连接的凝胶状结构.We presented a theory to study switching of polyzwitterion brushes by water vapor.Our theory model takes account of polyzwitterion-water(P-W)hydrogen bonds and zwitterions complex.We found that P-W hydrogen bonds become a key element in inducing swelling of polyzwitterion brushes.Our results indicate,because of zwitterionic complexes,the polyzwitterionic brushes take up less water molecules,which lead to a decline in water volume fraction in polyzwitterion brushes.We also investigated the phase diagram of polyzwitterion brushes.It is clearly indicated that the P-W hydrogen bonds are key elements in inducing swelling of polyzwitterion brushes,and water vapor inducing polyzwitterion brushes swell monotonically.On basis of our theory approach,we can predict that,because of P-W of hydrogen bonds,polyzwitterion brushes can adsorb water vapor;When the grafting density is too large,zwitterionic hybridization will lead to a zwitterionic complexe network formation of 3D polyzwitterion brushes.

关 键 词：水蒸气 两性离子聚合物刷 氢键 构象转变 

分 类 号：O484[理学—固体物理]