高分子物理凝膠化機理、結構形成與功能調控研究中期報告

童真+王朝陽+梁好均+梁德海+朱錦濤

摘 要：該研究針對不同相互作用類型、強度和距離的高分子物理凝膠體系（如：網絡尺寸均一與非均一的物理凝膠、聚電解質凝膠和高分子/無機納米雜化水凝膠、雙網絡增強水凝膠等），重點發展靜態與動態光散射、小角中子散射、固體核磁共振譜、激光共聚焦顯微鏡和微流變等方法，在不同尺度上研究物理凝膠化過程中分子鏈與鏈段由平衡態的各態歷經向平衡的非各態歷經轉變，理解物理凝膠的多層次結構及其動態結構多樣性的物理本質，明晰分子鏈“捕獲”和束縛溶劑在物理凝膠形成過程中的作用，分析物理凝膠形成過程中力學響應規律，不同尺度上認識高分子物理凝膠化機理及其結構與性能的調控機制。利用微流控技術制備尺寸精確可調的微凝膠，研究分子鏈在受限空間下的物理凝膠化機理和動態結構多樣性本質，結合在片（On-chip）包埋技術，為制備具有潛在應用前景、具有特殊環境響應能力（如：對光、電、磁等的響應）的多功能微凝膠材料提供科學依據。發展動態Monte Carlo、分子動力學、耗散粒子動力學和動態密度泛函等模擬方法，研究高分子物理凝膠及物理微凝膠模型體系的溶膠-凝膠轉變過程，認識物理交聯網絡幾何拓撲結構演化與凝膠化的關聯和體積相變的物理本質，明晰微凝膠顆粒在體積相變過程中力學性能的變化規律以及體積相變的尺寸依賴性，理解高分子物理凝膠特殊環境響應性的物理本質，拓展高分子物理凝膠化的理論模型。在實驗與模擬結果相互佐證的前提下，借助物理凝膠的刺激響應性和可逆性，通過調控高分子物理凝膠多層次結構和相互作用，實現特征松弛時間和特定結構尺寸的控制，為智能高分子凝膠材料的設計和制備提供指導。

關鍵詞：高分子物理凝膠 凝膠化 機理 結構 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

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