柔性抗冻导电凝胶的构筑

Construction of Flexible Antifreeze Conductive Gel

为解决传统水凝胶材料在低温时发生冻结,导致其部分力学功能丧失的问题,文中利用甘油体系纳米纤维素(CNC)与α-硫辛酸之间的氢键,再以FeCl3为交联剂,进一步诱导硫辛酸聚合形成凝胶网络,构筑了柔性抗冻导电凝胶CNC/α-硫辛酸凝胶。该凝胶具有优异的力学性能、导电性能及灵敏的应变传感性能。CNC/α-硫辛酸凝胶的拉伸性能和抗冻测试表明,甘油体系纳米纤维素含量为1.5 g时,凝胶的拉伸断裂应力达到16 kPa,断裂伸长率为805.5%,且在-40℃的低温条件下电导率仍能维持在0.029S/m,抗冻导电性能良好。应变传感性能测试表明,凝胶具有灵敏的应变传感能力,在应变150%~200%时,凝胶的灵敏度系数(GF)值达到2.36,能够进行人体运动监测,表明CNC/α-硫辛酸凝胶可作为柔性应变传感器用于智能可穿戴设备。

In order to solve the problem that traditional hydrogel materials freeze at low temperature,which leads to the loss of mechanical functions,this study made glycerol system nanocellulose andα-lipoic acid hydrogen bond,and then used FeCl3 as crosslinking agent to further induce the polymerization of lipoic acid to form a gel network,and constructed a flexible antifreeze conductive gel(CNC/α-lipoic acid gel).The gel has excellent mechanical properties,electrical conductivity and sensitive strain sensing properties.The tensile and antifreeze results of CNC/α-alpha-sulfuric acid gel show that when the content of nanocellulose in glycerol system is 1.5 g,the tensile fracture stress of the gel reaches 16 kPa,the elongation at break is 805.5%,and the conductivity remains at 0.029 S/m at the low temperature of-40℃,indicating good antifreeze conductivity.The strain sensing performance shows that the gel has a sensitive strain sensing ability.When the strain is 150%~200%,the sensitivity coefficient(GF)of the gel reaches 2.36,which can be used for human movement monitoring,indicating that CNC/α-lipoic acid gel can be used as flexible strain sensor for smart wearable devices.