高强韧自修复导电水凝胶制备、结构调控及其高灵敏传感器研究

Conductive polymer hydrogels have great potentials in applications including force sensors. It is highly desired to develop conductive hydrogels with very high strength, toughness, and self-healing properties. It remains a challenge to simultaneously improve the strength and conductivity of the hydrogels by manipulating the network structures and the interactions between the conductive polymers and the hydrogel networks. Herein, we propose to prepare tough and self-healing polymer networks through a combination of hydrophobic association crosslinking and hydrogen bonding, which serve as a skeleton for in situ polymerization of functional conjugate monomers (e.g., aniline) into conductive polymer network. Wherein, the conductive polymer networks are attached to the tough hydrogel network through non-covalent interactions including electrostatic attraction and/or hydrogen bonding. Some important issues will be addressed in details: (1) The effect of the network structures of the conductive hydrogels on the strength, toughness, and self-healing behavior; (2) The effect of non-covalent interactions between the conductive polymers and the hydrophilic network on the conductivity of the hydrogels, and (3) the relationship between the stress/strain and the conductivity of the hydrogels, and the key factors that determine such a relationship. The formulations and network structures will be optimized based on the results obtained from above studies to prepare tough and self-healing hydrogels with very high sensitivity to stress and strain. The hydrogels will be used to fabricate flexible arrayed sensors to be used to detect or monitor subtle changes in force, deformations or vibrations.

导电高分子水凝胶在力传感器等方面有重要的应用前景，发展高强韧、自修复型导电水凝胶，是相关基础科学和应用研究的迫切需求。如何构建高强韧且自修复的水凝胶网络，将导电网络与水凝胶网络密切结合，同时提升其物理机械性能和导电性能，是仍需解决的关键问题。本项目拟将疏水缔合与氢键协同作用，制备高强韧、抗疲劳且自修复的高分子水凝胶，以此为基质，通过氢键或静电作用将功能型苯胺等共轭分子吸附在水凝胶网络中，原位聚合，制备互穿网络结构导电水凝胶。着重研究：导电水凝胶网络结构对材料强度、韧性和自修复性能的影响；导电网络与水凝胶网络之间的非共价作用对导电性能的影响；凝胶的导电性能随应力应变的变化规律，阐明影响水凝胶电导率随应力应变响应灵敏度的关键因素，通过网络结构调控，制备高灵敏导电水凝胶。在此基础上，利用导电水凝胶的高灵敏度，制备若干柔性阵列式传感器，探索其在微弱力、形变或振动的检测或监测等方面的应用。

导电高分子水凝胶在柔性电子器件和电子皮肤等领域具有非常广阔的应用前景。本项目提出了“水凝胶仿生电子学”理念，制备了多网络水凝胶，研究了非共价作用影响机械性能和传感性能的规律；制备了组织粘附型水凝胶，监测组织器官运动；制备了仿生水凝胶，实现了水凝胶仿生驱动与传感一体化。.1、主要研究内容包括：.（1）研究了多重物理交联对多网络水凝胶的增强增韧原理。.（2）研究了导电水凝胶的网络结构影响导电性能、传感性能的规律。.（3）研究了聚两性离子水凝胶与组织器官之间的粘附机理。.（4）制备了仿生水凝胶传感器与驱动器，实现了驱动、传感、生物功能一体化。.2、取得的主要研究进展.（1）运用疏水缔合、氢键、离子络合、结晶等，制备了高强韧形状记忆多网络水凝胶，揭示了非共价作用对水凝胶脆-韧转变的影响规律。.（2）合成了互穿网络导电水凝胶，发现了“低阈渗导电”和线性传感行为；提出“纳米电容器”概念，制备了高灵敏应力传感器。.(3) 发展了“组织粘附水凝胶生物电子学”概念，合成了聚两性离子水凝胶，主要基于偶极作用，实现水凝胶-组织界面粘附，监测器官运动。.（4）运用增强增韧机制，研制了力响应型水凝胶和高强韧透明质酸水凝胶，应力诱导药物释放，促进皮肤创面抑菌、损伤愈合和软骨再生修复。.（5）制备了微颗粒水凝胶和纳米复合水凝胶，利用氢键、拥堵效应、温度响应等特性，实现剪切诱导的可逆溶胶-凝胶转变，解决了高分子水凝胶难以3D打印的难题，构建了仿生血管、骨骼和耳廓等结构。.（6）受生物组织启发，制备了交联密度可调控的各向异性水凝胶，构建了3D/4D水凝胶折纸驱动器。制备了碳纤维/PNIPAM复合水凝胶，构建了逻辑门、柔性触摸板和4D驱动器，实现了驱动-传感一体化。.3、主要成果.以第一或通讯作者在Advanced Functional Materials等期刊发表论文25篇，申请中国发明专利5项，获得2020年宁波市科技进步二等奖，2020年度Materials Horizons杰出论文奖。主导制定团体标准1项。.项目执行期内，培养博士研究生2名，硕士研究生11名，本科生4名。