Wang Yanqing, Li Pengcheng, Cao Shuting, Liu Yuetao, Gao Chuanhui
College of Chemical Engineering, Qingdao University of Science and Technology, Qingdao 266042, China.
Nanoscale. 2023 Nov 30;15(46):18667-18677. doi: 10.1039/d3nr03578f.
Hydrogel materials show promise in various fields, including flexible electronic devices, biological tissue engineering and wound dressing. Nevertheless, the inadequate mechanical properties, recovery performance, and self-healing speed still constrain the development of intelligent hydrogel materials. To tackle these challenges, we designed a composite hydrogel with high mechanical strength, rapid self-recovery and efficient self-healing ability based on multiple synergistic effects. With the synergistic effect of hydrogen bonds, metal coordination bonds and electrostatic interaction, the synthesized hydrogel could reach a maximum tensile strength of 6.2 MPa and a toughness of 50 MJ m. The interaction between the weak polyelectrolyte polyethyleneimine and polyacrylic acid aided in improving the elasticity of the hydrogel, thereby endowing it with prompt self-recovery attributes. The multiple reversible effects also endowed the hydrogel with excellent self-healing ability, and the fractured hydrogel could achieve 95% self-healing within 4 h at room temperature. By the addition of glycerol, the hydrogel could also cope with a variety of extreme environments in terms of moisture retention (12 h, maintaining 80% of its water content) and freeze protection (-36.8 °C) properties. In addition, the composite hydrogels applied in the field of shape memory possessed programmable and reversible shape transformation properties. The polymer chains were entangled at high temperatures to achieve shape fixation, and shape memory was eliminated at low temperatures, which allowed the hydrogels to be reprogrammed and achieve multiple shape transitions. In addition, we also assemble composite hydrogels as actuators and robotic arms for intelligent applications.
水凝胶材料在包括柔性电子器件、生物组织工程和伤口敷料等各个领域都展现出了潜力。然而,机械性能、恢复性能和自愈速度不足仍然制约着智能水凝胶材料的发展。为应对这些挑战,我们基于多种协同效应设计了一种具有高机械强度、快速自我恢复和高效自愈能力的复合水凝胶。通过氢键、金属配位键和静电相互作用的协同效应,合成的水凝胶可达到6.2兆帕的最大拉伸强度和50兆焦耳每立方米的韧性。弱聚电解质聚乙烯亚胺和聚丙烯酸之间的相互作用有助于提高水凝胶的弹性,从而赋予其迅速的自我恢复特性。多种可逆效应还赋予了水凝胶优异的自愈能力,在室温下,破裂的水凝胶在4小时内可实现95%的自愈。通过添加甘油,水凝胶在保湿(12小时,保持其80%的含水量)和防冻(-36.8℃)性能方面还能应对各种极端环境。此外,应用于形状记忆领域的复合水凝胶具有可编程和可逆的形状转变特性。聚合物链在高温下缠结以实现形状固定,在低温下形状记忆消除,这使得水凝胶能够重新编程并实现多次形状转变。此外,我们还将复合水凝胶组装成用于智能应用的致动器和机械臂。