羧基化填料对聚乙烯醇/纳米纤维素水凝胶力学、导电和传感性能的影响

Effect of carboxylate fillers on mechanical,conductive,and sensing performance of PVA/CNF hydrogel

利用羧基化碳纳米管(CNT)和纳米纤维素微晶(CNC)与聚乙烯醇/纳米纤维素(PVA/CNF)中形成氢键构建致密的交联网络,并对水凝胶进行增强改性。结果表明,加入3%(质量分数,下同)的CNT可以使水凝胶的拉伸强度由50 kPa提高至120 kPa,而加入3%的CNC能够同时提高水凝胶的拉伸强度和断裂伸长率;加入CNT后能够在水凝胶中构建导电逾渗网络,结合溶剂中的离子导电使得水凝胶的电阻率显著下降;使用PVA/CNF-CNT3水凝胶制作应变传感器,能够实现拉伸、压缩和弯曲等多种应变的快速、准确传感响应。

In this work,carboxylate carbon nanotubes(CNTs)and cellulose nanocrystals(CNC)were used to induce a dense crosslinking structure and act as reinforcement agents in poly(vinyl alcohol)(PVA)/cellulose nanofibers composite hydrogels. The results indicated that the tensile strength of the composite hydrogels increased from 50 kPa to 120 kPa with the addition of 3 wt % CNTs,whereas,their tensile strength and elongation at break both increased with the addition of 3 wt % CNC. Meanwhile,the electrical resistance of the composite hydrogels decreased significantly in the presence of CNT due to the formation of a conductive percolation threshold and ionic conductive paths. Therefore,the composite hydrogel with 3 wt % CNT can be selected as a sensing material. The hydrogels designed in this study exhibit a rapid and accurate sensing response to various stresses in tension,compression and bending.