水合作用与pH调控聚电解质刷的构象转变  

Hydration and pH-regulated switching of polyelectrolyte brush

作　　者：李康睿 马奭文 王利云 赵新军 LI Kang-Rui;MA Shi-Wen;WANG Li-Yun;ZHAO Xin-Jun(Xinjiang Laboratory of Phase Transitions and Microstructures in Condensed Matters,College of Physical Science and Technology,Yili Normal University,Yining 835000,China;Laboratory of Micro-Nano Electro Biosensors and Bionic Devices,Yili Normal University,Yining 835000,China)

机构地区：[1]伊犁师范大学物理科学与技术学院新疆凝聚态相变与微结构实验室,伊宁835000 [2]伊犁师范大学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》2024年第3期33-40,共8页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(22163011);伊犁师范大学科研创新团队培育计划(CXZK2021022)。

摘　　要：我们基于Flory-Huggins理论,建立理论模型研究水合作用与pH调控聚电解质刷的构象转变.理论模型考虑聚电解质链与水分子间的作用(聚电解质链的水合作用)、体系中的静电作用.研究发现,随着水合作用的改变,聚电解质刷出现由溶胀到塌缩的构象转变.由此表明了水合作用可在很大程度调节聚电解质刷的相变.通过分析pH的调控效应我们还发现,在碱性环境中(pH=8),聚电解质链单体的解离度增大,静电排斥会使得聚电解质刷溶胀.由此表明,聚电解质刷内水合作用与静电效应的耦合,将会共同决定聚电解质刷的构象转变特性.理论结果深刻揭示了水合作用的改变,会使得聚电解质刷体系发生相变,pH可在很大程度上改变其相变特性.Based on the Flory-Huggins theory, we established a theoretical model to study the conformational transition of polyelectrolyte brushes regulated by hydration and pH. The theoretical model considers the interaction between polyelectrolyte chains and water molecules (hydration of polyelectrolyte chains ) and electrostatic interactions in the system. We found that the polyelectrolyte brushes change from swelling to collapse with the change of hydration. This suggests that hydration can largely modulate the polyelectrolyte brush phase transition. By analyzing the regulation effect of pH, we also found that in an alkaline environment (pH=8 ), the dissociation degree of the polyelectrolyte chain monomer increases, and the electrostatic repulsion will make the polyelectrolyte brush swell. This suggests that the coupling of hydration and electrostatic effects in polyelectrolyte brushes will jointly determine the conformational transition properties of polyelectrolyte brushes. The theoretical results profoundly reveal that the change of hydration will cause the phase transition of the polyelectrolyte brush system, and the pH can change the phase transition characteristics to a large extent.

关 键 词：水合作用 PH 聚电解质刷 构象转变 

分 类 号：O484[理学—固体物理]