Yang Xule, Xu Liju, Wang Chen, Wu Jilin, Zhu Bin, Meng Xiaohui, Qiu Dong
Beijing National Laboratory for Molecular Sciences, Laboratory of Polymer Physics and Chemistry, CAS Research/Education Center for Excellence in Molecular Sciences, Institute of Chemistry, Chinese Academy of Sciences, Beijing, 100190, China.
University of Chinese Academy of Sciences, Beijing, 100049, China.
Adv Mater. 2023 Oct;35(42):e2303728. doi: 10.1002/adma.202303728. Epub 2023 Sep 17.
Nanofibrous hydrogels are pervasive in load-bearing soft tissues, which are believed to be key to their extraordinary mechanical properties. Enlighted by this phenomenon, a novel reinforcing strategy for polymeric hydrogels is proposed, where polymer segments in the hydrogels are induced to form nanofibers in situ by bolstering their controllable aggregation at the nanoscale level. Poly(vinyl alcohol) hydrogels are chosen to demonstrate the virtue of this strategy. A nonsolvent-quenching step is introduced into the conventional solvent-exchange hydrogel preparation approach, which readily promotes the formation of nanofibrous hydrogels in the following solvent-tempering process. The resultant nanofibrous hydrogels demonstrate significantly improved mechanical properties and swelling resistance, compared to the conventional solvent-exchange hydrogels with identical compositions. This work validates the hypothesis that bundling polymer chains to form nanofibers can lead to nanofibrous hydrogels with remarkably enhanced mechanical performances, which may open a new horizon for single-component hydrogel reinforcement.
纳米纤维水凝胶普遍存在于承重软组织中，据信这是它们具有非凡力学性能的关键。受这一现象启发，提出了一种用于聚合物水凝胶的新型增强策略，即通过在纳米尺度上增强水凝胶中聚合物链段的可控聚集，诱导其原位形成纳米纤维。选择聚乙烯醇水凝胶来证明该策略的优点。在传统的溶剂交换水凝胶制备方法中引入非溶剂猝灭步骤，这在随后的溶剂回火过程中很容易促进纳米纤维水凝胶的形成。与具有相同组成的传统溶剂交换水凝胶相比，所得纳米纤维水凝胶表现出显著改善的力学性能和抗溶胀性。这项工作验证了这样一个假设，即捆绑聚合物链以形成纳米纤维可以导致具有显著增强力学性能的纳米纤维水凝胶，这可能为单组分水凝胶增强开辟新的前景。
