School of Chemistry and Chemical Engineering, Shandong University, Jinan 250100, China.
Soft Matter. 2019 Dec 4;15(47):9797-9804. doi: 10.1039/c9sm01597c.
The strategy of dual cross-linking was investigated by enhancing the performance of dynamic hydrogels. To this end, phenylalanine modified ε-polylysine was synthesized and employed as the polymer backbone of hydrogels. The phenylalanine moieties and amine groups of the polymer could be cross-linked with cucurbit[8]uril (CB[8]) and the dialdehyde cross-linker, respectively. Single CB[8] linkage with fast dynamics led to an increase in the viscosity of the polymer solution, and single imine linkage with slow dynamics led to the formation of weak and brittle hydrogels. However, the two linkages were combined together to form a dual-cross-linked hydrogel and the performance of the hydrogel could be well enhanced. Compared with the single imine cross-linked hydrogel, the dual-cross-linked hydrogel demonstrated a higher mechanical strength, better extensibility and faster self-healing rate. It is anticipated that this line of research could provide a useful method to enhance the performance of dynamic hydrogels.
双交联策略通过增强动态水凝胶的性能进行了研究。为此，合成了苯丙氨酸改性的ε-聚赖氨酸，并将其用作水凝胶的聚合物主链。聚合物中的苯丙氨酸部分和氨基可以分别与葫芦[8]脲（CB[8]）和二醛交联剂交联。具有快速动力学的单个 CB[8]键合导致聚合物溶液的粘度增加，而具有缓慢动力学的单个亚胺键合导致形成弱而脆的水凝胶。然而，这两个键合在一起形成了双交联水凝胶，并且水凝胶的性能可以得到很好的增强。与单亚胺交联水凝胶相比，双交联水凝胶表现出更高的机械强度、更好的拉伸性和更快的自修复速率。预计这条研究路线可以为增强动态水凝胶的性能提供一种有用的方法。
