瓜尔胶酯基高强韧自修复水凝胶的构筑及其传感性能研究

Due to its biodegradability, renewability and non-toxicity, biomass-based hydrogel is thereby considered as a promising material with low impact on the environment. A novel guar gum ester-based hydrogel, using alkenyl succinic anhydride guar gum ester as raw material, will prepare via a free radical polymerization method. This program will investigate the affection of the length of side group, hydrophobic association, metal ion coordination, boric acid ester bond and dual network structure on the energy dissipation of hydrogels during deformation and recovery processes; besides, the microstructure of the hydrogel will be analyzed by means of solid NMR, IR, SEM and XRD. We will further discuss the relationship between mechanical properties and microstructures of the hydrogel and propose the mechanism of toughening and reinforcing. Moreover, we will also investigate the reversible network on self-healing, shape memory properties of guar gum ester-based hydrogel and elucidating the mechanism of self-healing, shape memory of guar gum eater-based hydrogel. Then, a wearable soft strain sensor will be assembled based on these characteristics of the hydrogel, and its strain-sensitive performance will be further investigated. Our findings will provide a new possibility for fabricating wearable strain-sensitive device. In conclusion, this study will enrich the type of biomass-based hydrogel and has great theoretical and practical significance.

生物质基水凝胶以其良好的生物相容性和可降解性，具有广阔的应用前景。本项目以烯基琥珀酸酐改性的瓜尔胶为原料，采用自由基聚合法制备聚烯基琥珀酸瓜尔胶酯水凝胶，考察侧基碳链长度、疏水缔合作用、金属配位作用、硼酸酯键及双网络结构对水凝胶形变过程能量损耗的影响，利用固体NMR、IR、SEM、X射线衍射等结构分析手段解析材料的微观结构，深入研究水凝胶的结构与力学性能的关系，揭示瓜尔胶酯基水凝胶的增强增韧机理；进一步考察水凝胶内部可逆交联网络对其自修复和形状记忆性能的影响，阐明瓜尔胶酯基水凝胶的自修复与形状记忆机理；在此基础上，构建新型多功能瓜尔胶酯基水凝胶传感器件，研究其传感性能，为水凝胶应变传感器应用于可穿戴设备领域提供新思路和新方法。本项目拓展了生物质基水凝胶的类型，具有重要的理论意义和应用前景。

随着科技的发展，越来越多的功能高分子材料特别是软物质材料，被应用到人们的日常生产生活中。软物质材料因其独特的柔韧性、多功能性和卓越的机械性能吸引了越来越多研究人员的关注。本项目系统研究了以瓜尔胶及其衍生物为原料制备水凝胶，并考察了水凝胶的理化性能，初步探讨了其在柔性夹爪机器人中的应用。主要研究内容包括：（1）以瓜尔胶为原料制备了水凝胶，该水凝胶通过加入四硼酸钠引入硼酸酯键构筑瓜尔胶-硼砂超分子水凝胶，这种水凝胶具有显著的自修复性能和凝胶-溶胶转换特性。（2）以阳离子瓜尔胶为原料制备了水凝胶，该水凝胶通过阳离子瓜尔胶与丙烯酰胺复合形成了阳离子瓜尔胶-丙烯酰胺复合水凝胶，其具有较好的机械性能和形状记忆性能，CGG浓度为2%时的复合水凝胶拉伸应力为0.13MPa、拉伸应变为2130%，将CGG浓度为2%的水凝胶浸泡饱和柠檬酸钠溶液12h后，拉伸应力增大至0.54MPa，是原始复合水凝胶的4.15倍，拉伸应变为900%，浸泡饱和柠檬酸钠溶液35min的形状记忆率为80%。（3）以2-辛烯基琥珀酸酐为改性剂，对GG进行均相改性，成功制备了辛烯基琥珀酸瓜尔胶酯（OG），然后以OG为原料采用自由基聚合法制备了辛烯基琥珀酸瓜尔胶酯水凝胶，研究了该水凝胶的机械性能和形状记忆性能，OG浓度为10%时的水凝胶拉伸应力为20KPa、拉伸应变为380%；将其浸泡于0.1 mol/L的FeCl3溶液12h后的拉伸应力增大至1.09MPa，拉伸应力提高了54.5倍，拉伸应变为218%，浸泡0.1mol/L的FeCl3溶液1min时的形状记忆率为90%。（4）初步探索了瓜尔胶基水凝胶在柔性夹爪机器人中的应用，因本项目制备的水凝胶具有良好的导电性能，水凝胶因发生形变从而产生电阻值的变化，该变量可作为柔性夹爪控制系统输入量，气动控制器根据反馈信号调整气压大小来控制柔性夹爪实现灵活抓取的功能。