张雁云做报告-国家重大科学研究计划 组织干细胞在器官衰老与再生中...
童真+王朝阳+梁好均+梁德海+朱锦涛
摘 要：该研究针对不同相互作用类型、强度和距离的高分子物理凝胶体系（如：网络尺寸均一与非均一的物理凝胶、聚电解质凝胶和高分子/无机纳米杂化水凝胶、双网络增强水凝胶等），重点发展静态与动态光散射、小角中子散射、固体核磁共振谱、激光共聚焦显微镜和微流变等方法，在不同尺度上研究物理凝胶化过程中分子链与链段由平衡态的各态历经向平衡的非各态历经转变，理解物理凝胶的多层次结构及其动态结构多样性的物理本质，明晰分子链“捕获”和束缚溶剂在物理凝胶形成过程中的作用，分析物理凝胶形成过程中力学响应规律，不同尺度上认识高分子物理凝胶化机理及其结构与性能的调控机制。利用微流控技术制备尺寸精确可调的微凝胶，研究分子链在受限空间下的物理凝胶化机理和动态结构多样性本质，结合在片（On-chip）包埋技术，为制备具有潜在应用前景、具有特殊环境響应能力（如：对光、电、磁等的响应）的多功能微凝胶材料提供科学依据。发展动态Monte Carlo、分子动力学、耗散粒子动力学和动态密度泛函等模拟方法，研究高分子物理凝胶及物理微凝胶模型体系的溶胶-凝胶转变过程，认识物理交联网络几何拓扑结构演化与凝胶化的关联和体积相变的物理本质，明晰微凝胶颗粒在体积相变过程中力学性能的变化规律以及体积相变的尺寸依赖性，理解高分子物理凝胶特殊环境响应性的物理本质，拓展高分子物理凝胶化的理论模型。在实验与模拟结果相互佐证的前提下，借助物理凝胶的刺激响应性和可逆性，通过调控高分子物理凝胶多层次结构和相互作用，实现特征松弛时间和特定结构尺寸的控制，为智能高分子凝胶材料的设计和制备提供指导。
关键词：高分子物理凝胶 凝胶化 机理 结构 功能
Abstract：Physical gelation of polymers is considered to be the “capture” of molecular chains in a certain time and space scales， the formation of physical crosslinking between molecular chains， and the transition of molecular chain movements from ergodic to non-ergodic. There exists large difference on the structure size obtained from dynamic rheological and the neutron scattering， which indicates that the physical gel of polymers has the structural multilevel property， this property leads to the completely different behaviors of the gels on different relaxation time or mechanical response. Thus， to understand the physical gelation mechanism and the essence of its dynamic structure diversity are significant to the design of polymer gels. The present project aims at physical gel systems with interactions of different types， strength and distance， the project focuses on the development of different methods to study the transition of molecular chains and segment from ergodic at equilibrium state to non-ergodic at equilibrium state during the physical gelation process at different scales， to understand the multilevel structure of physical gels and the physical essence of its dynamic structure diversity， to clarify the function of the “capture” of molecular chains and bound solvent during the formation of physical gels， and to analyze the mechanical response laws during the formation of physical gels to know the gelation mechanism and ways of adjusting the structure and property of gels at different scales. On the basis of the certifiable results between experiments and simulation， the controlling of characteristic relaxation time and structural size could be realized with the stimuli-responsibility and reversibility of physical gels and by adjusting the multilevel structure of physical gels and interactions， which can provide the guidance to the design and preparation of intelligent polymer gel materials.
Key Words：Polymer physical gel； Gelation； Mechanism； Structure； Function
阅读全文链接（需实名注册）：http：//www.nstrs.cn/xiangxiBG.aspx？id=49013&flag=1
