Chen Zeyu, Zhong Wenbin
College of Materials Science and Engineering, Hunan University, Changsha 410082, China.
Materials (Basel). 2025 Apr 15;18(8):1800. doi: 10.3390/ma18081800.
Zwitterionic polymer hydrogels have great application prospects in wearable electronic devices due to their antifouling and excellent biocompatibility. However, its strong hydrophilicity often leads to easy swelling and poor mechanical properties. In this study, aramid nanofiber (ANF)-reinforced zwitterionic ion hydrogels were synthesized by the one-step free radical polymerization of -acryloyl glycinamide (NAGA), -[Tris (hydroxymethyl) methyl] acrylamide (THMA) and sulfobetaine methacrylate (SBMA) monomers in the presence of ANFs. A large number of hydrogen bonds were formed between the amide groups of the ANFs and the amide groups of the NAGA units/the hydroxyl groups of the THMA units/the sulfonic groups of the SBMA units, which improved the internal interface force of the hydrogel. The obtained ANF-reinforced hydrogel had an anti-swelling property, and its swelling ratio and tensile strength were 25% and 170% of those of the hydrogel without the addition of ANFs. By introducing lithium chloride as an electrolyte to improve its ion conductivity and subsequently assembling it into strain sensors, it exhibited a high sensitivity (GF = 1.12), short response and recovery times (100 ms and 150 ms), and excellent cycling stability. This work provides a feasible strategy for anti-swelling wearable strain sensors.
两性离子聚合物水凝胶因其抗污性和优异的生物相容性在可穿戴电子设备中具有巨大的应用前景。然而，其强亲水性常常导致易于溶胀且力学性能较差。在本研究中，通过在芳纶纳米纤维（ANF）存在下使N-丙烯酰甘氨酰胺（NAGA）、N-[三（羟甲基）甲基]丙烯酰胺（THMA）和甲基丙烯酸磺酸甜菜碱（SBMA）单体进行一步自由基聚合，合成了ANF增强的两性离子水凝胶。ANF的酰胺基团与NAGA单元的酰胺基团/THMA单元的羟基/SBMA单元的磺酸基团之间形成了大量氢键，这提高了水凝胶的内部界面力。所制备的ANF增强水凝胶具有抗溶胀性能，其溶胀率和拉伸强度分别为未添加ANF的水凝胶的25%和170%。通过引入氯化锂作为电解质以提高其离子电导率，随后将其组装成应变传感器，该传感器表现出高灵敏度（GF = 1.12）、短响应和恢复时间（100 ms和150 ms）以及优异的循环稳定性。这项工作为抗溶胀可穿戴应变传感器提供了一种可行的策略。
