纤维素纳米纤维基抗冻双网络凝胶的制备及其应变传感性能研究

Preparation of cellulose nanofibre-based antifreeze double network gels and their strain sensing properties

关键词:  纤维素纳米纤维  双网络凝胶  抗冻性能  人体运动监测

Key Words:cellulose nanofibres  double network gel  frost resistance  human movement monitoring

摘要:本研究以聚乙烯醇（PVA）和丙烯酰胺（AM）为单体，采用乙二醇（EG）和氯化锌（ZnCl2）制备低共熔溶剂（DES），以DES代替传统的水溶剂，并引入纤维素纳米纤维（CNF）以增强力学性能，从而制备出DES-PVA/PAM/CNF双网络抗冻凝胶。研究结果表明，当ZnCl2与EG的摩尔比为1:5时，所制备的DES-PVA/PAM/CNF抗冻双网络凝胶表现出最佳的抗冻性能，冰点低至-73.03℃。进一步探究CNF含量对凝胶性能的影响时发现当CNF含量为EG质量的0.4% 时，凝胶的综合性能最优。在室温条件下，该凝胶的断裂强度可达0.94 MPa，断裂伸长率为844.5%；而在低温环境下，其断裂强度仍能保持在0.92 MPa，从而验证了该抗冻凝胶的优异低温适应性。此外，将该凝胶组装为应变传感器后，成功实现了对人体皮肤贴附式运动的监测。

Abstract:In this study, DES-PVA/PAM/CNF double network antifreeze gels were prepared by using polyvinyl alcohol (PVA) and acrylamide (AM) as monomers, using ethylene glycol (EG) and zinc chloride (ZnCl2) for the preparation of low eutectic solvents (DES), replaced the conventional aqueous solvents with DES, and introducing cellulose nanofibres (CNFs) to enhance the mechanical properties. The results showed that the prepared DES-PVA/PAM/CNF antifreeze double network gels exhibited the best antifreeze performance with freezing point as low as -73.03°C when the molar ratio of ZnCl2 to EG was 1:5. Further investigation of the effect of CNF content on the gel properties revealed that the best overall performance was achieved when the CNF content was 0.4% of the EG mass. At room temperature, the fracture strength of the gel was up to 0.94 MPa, and the elongation at break was 844.5%; at low temperature, the fracture strength was still maintained at 0.92 MPa, which verified the excellent low-temperature adaptability of the antifreeze gel. In addition, after assembling the gel as a strain sensor, the monitoring of human skin-attached motion was successfully realised.