College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China; Xi'an Key Laboratory of Green Chemicals and Functional Materials, Xi'an 710021, China; National Demonstration Center for Experimental Light Chemistry Engineering Education, Xi'an 710021, China.
College of Bioresources Chemical and Materials Engineering, Shaanxi University of Science & Technology, Xi'an 710021, China; National Demonstration Center for Experimental Light Chemistry Engineering Education, Xi'an 710021, China.
Int J Biol Macromol. 2023 May 31;238:124055. doi: 10.1016/j.ijbiomac.2023.124055. Epub 2023 Mar 21.
Flexible hydrogels have emerged as highly-desirable materials for wearable strain sensors. However, pristine biomass hydrogel systems are limited by their lack of stretchability, self-adhesion, and sensitivity. Here, a novel CA/MWCNT/PAAm double-network conductive hydrogel was developed through integrating casein (CA) micelles and multi-walled carbon nanotubes (MWCNT) into the polyacrylamide (PAAm) network. The resulting hydrogel displayed desired properties such as adhesiveness, toughness, self-healing, and near-infrared photothermal response. In this hybrid system, MWCNT were uniformly dispersed in the presence of casein micelles through hydrogen bonding and electrostatic interactions, favoring its role of nano reinforcement. Moreover, based on the "casein micelle-nanoparticle double cross-linking" mechanism and its double network structure, the prepared hydrogel showed high extensibility (2288 % ± 63 %), fast responsiveness (273 ± 5.13 ms), high sensitivity (GF = 12.46 ± 0.35), and a wide strain range (1-1000 %). Through consistent and repeated electrical inputs, this hydrogel was able to detect including large and small human movements, such as hand, leg, and swallowing motions. The results from this study provide a new way to fabricate bio-based hydrogel sensors with excellent mechanical and electrical properties.
弹性水凝胶作为可穿戴应变传感器的理想材料已经出现。然而，原始生物质水凝胶系统受到其拉伸性、自粘性和灵敏度的限制。在这里，通过将酪蛋白（CA）胶束和多壁碳纳米管（MWCNT）整合到聚丙烯酰胺（PAAm）网络中，开发了一种新型 CA/MWCNT/PAAm 双网络导电水凝胶。所得水凝胶具有粘附性、韧性、自修复和近红外光热响应等所需性能。在这个混合系统中，MWCNT 通过氢键和静电相互作用均匀分散在酪蛋白胶束中，有利于其纳米增强作用。此外，基于“酪蛋白胶束-纳米颗粒双重交联”机制及其双网络结构，所制备的水凝胶表现出高拉伸性（2288%±63%）、快速响应性（273±5.13ms）、高灵敏度（GF=12.46±0.35）和宽应变范围（1-1000%）。通过一致和重复的电输入，这种水凝胶能够检测包括手、腿和吞咽运动在内的大、小人体运动。这项研究的结果为制造具有优异机械和电气性能的基于生物的水凝胶传感器提供了一种新方法。
