基于预拉伸工艺的高强韧和耐磨离子导电水凝胶制备及其性能分析

Preparation and properties of ionic conductive hydrogels with high strength,toughness and wear resistance based on pre-tensile process

为提高导电水凝胶的机械强度、抗疲劳稳定性等性能,采用预拉伸工艺制备高强韧和耐磨离子导电水凝胶。以兼具生物相容性和力学柔韧性的黄原胶(XG)和聚乙烯醇(PVA)为主要原料,通过冷冻、预拉伸和柠檬酸钠(Na_(3)Cit)浸泡盐析的方法制备导电水凝胶,使其具有双网络结构;优化预拉伸工艺参数,并将导电水凝胶精心制成柔性传感器,探究其传感响应能力。结果表明:当预拉伸比由0增加到5%时,所制备的导电水凝胶拉伸断裂强度由3.0 MPa提升到7.5 MPa,耐磨性能从5.0 MPa提升至6.0 MPa,导电性能也从0.05S/m提升至0.75S/m,所得导电水凝胶能很好地应用于人体交互系统,对人体喉咙吞咽、腕关节弯曲、指关节弯曲都能有效监测。预拉伸作用有效提高了导电水凝胶分子链的各向同性,同时提高了导电水凝胶的力学性能、耐磨性能和导电性能。该研究可为导电水凝胶在智能可穿戴柔性传感器领域中的应用提供基础。

In order to improve the mechanical strength and anti-fatigue stability of conductive hydrogels,ionic conductive hydrogels with high strength,toughness and wear resistance were prepared by pre-tensile process.With Xanthan gum(XG)and polyvinyl alcohol(PVA)with both biocompatibility and mechanical flexibility as the main raw materials,the conductive hydrogel was prepared by freezing,pre-stretching and sodium citrate(Na_(3)Cit)soaking salting out to make it have dual network structure.The pre-drawing process parameters were optimized,and the conductive hydrogel was carefully fabricated into a flexible sensor to explore its sensing response ability.The results showed that when the pre-tensile ratio increased from 0 to 5%,the tensile fracture strength of the prepared conductive hydrogel increased from 3.0 MPa to 7.5 MPa,the wear resistance increased from 5.0 MPa to 6.0 MPa,and the conductive property also increased from 0.05 S/m to 0.75 S/m.The obtained conductive hydrogel can be well applied to the human interactive system.The swallowing of human throat,wrist bending and knuckle bending can be effectively monitored.The isotropy of the molecular chains and the mechanical properties,wear resistance and electrical conductivity of the conductive hydrogel were improved by pre-stretching.The research can provide the basis for the application of conductive hydrogels in the field of intelligent wearable flexible sensors.