Zhu Yuan, Li Xuemei, Zhao Zhenjie, Liang Yongri, Wang Limin, Liu Yingdan
State Key Lab of Metastable Materials Science and Technology, College of Materials Science and Engineering, Yanshan University, Qinhuangdao 066004, China.
Gels. 2022 Dec 5;8(12):797. doi: 10.3390/gels8120797.
A stretchable double-network (DN) ionogel composed of a physically crosslinked network of chitosan (CS) and a chemically crosslinked network of polyacrylic acid (PAA) was prepared in an ionic liquid ([EMIM][OAc]) using a one-step polymerization method. In this ionogel (CS/PAA), the CS and the PAA polymer chains served as backbones, which constructed an interpenetrating DN structure via numerous hydrogen bonds formed through the hydroxyl, amino and carboxyl groups on the polymer chains. The DN structure improves the mechanical properties of the ionogel. Therefore, the CS/PAA DN ionogel exhibited outstanding mechanical performance in many ways: tensile strength up to 2.04 MPa, strain range up to 1046% and the value of toughness up to 8.52 MJ/m. The ionogel also showed good self-recovery performance, fatigue resistance, ability to work in a broad temperature range (-20~80 °C) and adhesion properties. As a flexible sensor, the CS/PAA DN ionogel showed high strain sensitivity (gauge factor = 6.235). It can sensitively detect human motion (such as joint-bending, vocal fold vibration, walking gait and other human body motions), revealing the practical application potential of flexible electronic devices.
采用一步聚合法在离子液体（[EMIM][OAc]）中制备了一种由壳聚糖（CS）物理交联网络和聚丙烯酸（PAA）化学交联网络组成的可拉伸双网络（DN）离子凝胶。在这种离子凝胶（CS/PAA）中，CS和PAA聚合物链作为主链，通过聚合物链上的羟基、氨基和羧基形成的大量氢键构建了互穿的双网络结构。双网络结构改善了离子凝胶的机械性能。因此，CS/PAA DN离子凝胶在许多方面表现出优异的机械性能：拉伸强度高达2.04 MPa，应变范围高达1046%，韧性值高达8.52 MJ/m³。该离子凝胶还表现出良好的自恢复性能、抗疲劳性能、在较宽温度范围（-20~80°C）工作的能力以及粘附性能。作为一种柔性传感器，CS/PAA DN离子凝胶表现出高应变灵敏度（应变片系数=6.235）。它能够灵敏地检测人体运动（如关节弯曲、声带振动、行走步态等人体运动），揭示了柔性电子器件的实际应用潜力。
