Tough, rapid-recovery composite hydrogels fabricated via synergistic core-shell microgel covalent bonding and Fe3+
Xuechen Liang1, Yukun Deng1, Xiaopeng Pei2
1Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, Jilin, P. R. China. xukun@ciac.ac.cn tanying@ciac.ac.cn and University of Chinese Academy of Sciences, Beijing 100049, P. R. China.
Abstract:
We developed tough, rapid-recovery composite hydrogels that are fabricated via core-shell microgel covalent bonding and Fe3+ dynamic metal coordination cross-linking. First, core-shell microgels are used as cross-linking agents and initiators to prepare homogeneous hydrogel networks with rapid recovery in the absence of an organic cross-linking agent. The toughness and recoverability of the composite hydrogels can be improved by adding the dynamic reversibility of ionic cross-linking. Owing to the synergistic effect of microgel covalent bonding, Fe3+ coordination cross-linking, and H-bond cross-linking, the multi-cross-linked composite hydrogels exhibit excellent toughness and a fast recovery rate. These characteristics demonstrate that the dynamic reversibility of the ionic cross-linking can significantly improve the toughness and recoverability of the hydrogels. In addition, the core-shell microgels play a key role in toughening the hydrogels and accelerating their recovery by transferring stress to grafted polymer chains and homogenizing the hydrogel network.
