Chen Chen-Kang, Chen Po-Wen, Wang Huan-Jung, Yeh Mei-Yu
Department of Chemistry, Chung Yuan Christian University, No. 200, Zhongbei Rd., Zhongli Dist., Taoyuan City 320314, Taiwan.
Center for Nano Technology, Chung Yuan Christian University, No. 200, Zhongbei Rd., Zhongli Dist., Taoyuan City 320314, Taiwan.
Gels. 2021 Oct 5;7(4):164. doi: 10.3390/gels7040164.
Conductive hydrogels with stretchable, flexible and wearable properties have made significant contributions in the area of modern electronics. The polyacrylamide/alginate hydrogels are one of the potential emerging materials for application in a diverse range of fields because of their high stretch and toughness. However, most researchers focus on the investigation of their mechanical and swelling behaviors, and the adhesion and effects of the ionic liquids on the conductivities of polyacrylamide/alginate hydrogels are much less explored. Herein, methacrylated lysine and different alkyl chain substituted imidazole-based monomers (IMCx, x = 2, 4, 6 and 8) were introduced to prepare a series of novel pAMAL-IMCx-Ca hydrogels. We systematically investigated their macroscopic and microscopic properties through tensile tests, electrochemical impedance spectra and scanning electron microscopy, as well as Fourier transform infrared spectroscopy, and demonstrated that an alkyl chain length of the IMCx plays an important role in the designing of hydrogel strain sensors. The experiment result shows that the hexyl chains of IMC6 can effectively entangle with LysMA through hydrophobic and electrostatic interactions, which significantly enhance the mechanical strength of the hydrogels. Furthermore, the different strain rates and the durability of the pAMAL-IMC6-Ca hydrogel were investigated and the relative resistance responses remain almost the same in both conditions, making it a potential candidate for wearable strain sensors.
具有可拉伸、柔性和可穿戴特性的导电水凝胶在现代电子领域做出了重大贡献。聚丙烯酰胺/藻酸盐水凝胶因其高拉伸性和韧性，是有望应用于众多领域的新兴材料之一。然而，大多数研究人员专注于研究它们的力学和溶胀行为，而离子液体对聚丙烯酰胺/藻酸盐水凝胶电导率的粘附作用和影响则较少被探索。在此，引入甲基丙烯酸化赖氨酸和不同烷基链取代的咪唑基单体（IMCx，x = 2、4、6和8）来制备一系列新型的pAMAL-IMCx-Ca水凝胶。我们通过拉伸试验、电化学阻抗谱、扫描电子显微镜以及傅里叶变换红外光谱系统地研究了它们的宏观和微观性质，并证明IMCx的烷基链长度在水凝胶应变传感器的设计中起着重要作用。实验结果表明，IMC6的己基链可以通过疏水和静电相互作用与LysMA有效缠结，这显著提高了水凝胶的机械强度。此外，研究了pAMAL-IMC6-Ca水凝胶在不同应变率和耐久性条件下的情况，在这两种条件下相对电阻响应几乎保持不变，使其成为可穿戴应变传感器的潜在候选材料。
