Advanced Rheology Institute, Department of Polymer Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Advanced Rheology Institute, Department of Polymer Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240, PR China.
Carbohydr Polym. 2020 Feb 15;230:115596. doi: 10.1016/j.carbpol.2019.115596. Epub 2019 Nov 11.
Hybrid double network (DN) hydrogels have been fabricated by combining a physically cross-linked κ-carrageenan network, where various cations were used as cross-linker, with a covalently cross-linked polyacrylamide (PAAm) network. Compared to monovalent K and divalent Ca cations, the presence of K/Ca mixture cations produced a well interconnected porous structure due to the synergistic effect, which simultaneously improved the strength and toughness of the resulting DN hydrogel. A model has been proposed considering the dissociation asynchronism of double-helical aggregates, which well interpret the fracture process and toughening mechanism of the K/Ca-cross-linked κ-carrageenan/PAAm DN hydrogel. Moreover, the synergistic effect of K/Ca mixture cations also improved the recovery efficiency at room temperature and self-healing ability of DN hydrogel. The strategy of synergistic interaction presented here provides an alternative view for the fabrication of hybrid DN hydrogels with desirable mechanical performance and functional property.
混合双网络（DN）水凝胶是通过将物理交联的κ-卡拉胶网络（其中使用各种阳离子作为交联剂）与共价交联的聚丙烯酰胺（PAAm）网络结合而制备的。与单价 K 和二价 Ca 阳离子相比，由于协同效应，K/Ca 混合阳离子的存在产生了良好的互连多孔结构，同时提高了所得 DN 水凝胶的强度和韧性。提出了一个考虑双螺旋聚集体解离异步性的模型，该模型很好地解释了 K/Ca 交联κ-卡拉胶/PAAm DN 水凝胶的断裂过程和增韧机理。此外，K/Ca 混合阳离子的协同效应还提高了 DN 水凝胶在室温下的恢复效率和自修复能力。这里提出的协同相互作用策略为具有理想力学性能和功能特性的混合 DN 水凝胶的制备提供了一种替代方法。
