【作者】 王曼；

【导师】 刘河洲； 陈玉洁；

【作者基本信息】 上海交通大学 ， 材料学， 2019， 硕士

【摘要】 近年来,由于导电水凝胶具有良好的电学性能、可调的机械性能与独特的生物学特性,被广泛地应用于柔性电子器件领域。但在实际应用过程中,水凝胶易被破坏影响产品使用寿命。因此,设计同时具有导电性与快速自修复性的水凝胶具有重要意义。本论文制备了聚乙烯醇基快速自修复导电水凝胶并对其性能进行研究。首先,我们用多巴胺（DA）还原氧化石墨烯（GO）得到部分还原氧化石墨烯（pRGO）。然后将pRGO加入聚乙烯醇（PVA）与硼砂（borax）交联形成的网络中从而获得聚乙烯醇-聚多巴胺-部分还原氧化石墨烯（PVA-PDA-pRGO）水凝胶。在该体系里,pRGO赋予水凝胶导电性(2.7mS·cm^-1)并增强水凝胶。同时,体系中可逆的二醇硼酸酯键与氢键使水凝胶在力学、电学和流变学修复实验中表现出卓越的快速自修复能力。在无外界刺激下被切断的水凝胶修复4.2 s后,其电阻值可恢复至初始电阻值的96.7%。修复60 s后,其拉伸强度可恢复至初始拉伸强度的92.89%。聚多巴胺（PDA）上的邻苯二酚基团能与Fe³⁺形成金属配位键,且其配位结构受环境pH影响。故我们在PVA-PDA-pRGO水凝胶体系中加入Fe³⁺,并调节体系pH使聚多巴胺上的邻苯二酚基团与Fe³⁺形成三重配位结构,从而作为物理交联点进一步增强水凝胶。被增强的水凝胶仍具有快速自修复能力。断裂的水凝胶修复60 s后,其拉伸强度可恢复至初始拉伸强度的88.67%。此外,由于导电水凝胶具有应变敏感性,我们以其为感应单元构建了监测人体行为变化的柔性传感器。更多还原

【Abstract】 In recent years,conductive hydrogels have been widely applied in the field of flexible electronic devices due to their good electronic properties,tunable mechanical performance and unique biological characteristics.However,hydrogels are easily destroyed during the course of use,which damages the life span of products.Therefore,it is vital to design the hydrogel with synergistic characteristics of rapid self-healing property and conductivity.Here,polyvinyl alcohol-based hydrogels with rapid self-healing performance and conductive capability were prepared.Firstly,GO was partially reduced by DA.Then PVA-PDA-pRGO hydrogel was prepared by adding pRGO into the network formed by PVA and borax.In this system,pRGO provided conductivity(2.7 mS·cm^-1)for hydrogel and the hydrogel was also strengthened by pRGO.Meanwhile,reversible diol borate bonds and hydrogen bonds allowed the hydrogel to display decent self-healing behaviors in mechanical（restore 92.89%of original tensile strength within 60 s）,electrical（restore 96.7%of original resistance within 4.2 s）and rheological recovery experiments without any external stimuli.The catechol groups on PDA can form metal coordinate bonds with Fe³⁺,and the coordination structure is affected by pH.Therefore,we added Fe³⁺to the PVA-PDA-pRGO hydrogel and adjusted the pH of system to form triple coordination structures.The triple coordination structure could be regarded as physical cross-linking points to strengthen hydrogel.In addition,this strengthened hydrogel still had fast self-healing ability.The damaged hydrogel could recover 88.67%of original tensile strength in 60 s without any external assistance.Furthermore,the conductive hydrogels showed strain-sensitivity so the soft strain sensors assembled by designed hydrogels were prepared to observe human movements.更多还原