Ma Yvqing, Gong Jixian, Li Qiujin, Liu Xiuming, Qiao Changsheng, Zhang Jianfei, Zhang Songnan, Li Zheng
State Key Laboratory of Separation Membranes and Membrane Processes/ National Center for International Joint Research on Separation Membranes/Key Laboratory of Advanced Textile Composites of Ministry of Education, School of Textile Science and Engineering, Tiangong University, Tianjin, 300387, P. R. China.
School of Biological Engineering, Tianjin University of Science and Technology, Tianjin, 300457, P. R. China.
Small. 2024 Jun;20(25):e2310046. doi: 10.1002/smll.202310046. Epub 2024 Jan 6.
Hydrogels are widely used in tissue engineering, soft robotics and wearable electronics. However, it is difficult to achieve both the required toughness and stiffness, which severely hampers their application as load-bearing materials. This study presents a strategy to develop a hard and tough composite hydrogel. Herein, flexible SiO nanofibers (SNF) are dispersed homogeneously in a polyvinyl alcohol (PVA) matrix using the synergistic effect of freeze-drying and annealing through the phase separation, the modulation of macromolecular chain movement and the promotion of macromolecular crystallization. When the stress is applied, the strong molecular interaction between PVA and SNF effectively disperses the load damage to the substrate. Freeze-dried and annealed-flexible SiO nanofibers/polyvinyl alcohol (FDA-SNF/PVA) reaches a preferred balance between enhanced stiffness (13.71 ± 0.28 MPa) and toughness (9.9 ± 0.4 MJ m). Besides, FDA-SNF/PVA hydrogel has a high tensile strength of 7.84 ± 0.10 MPa, super elasticity (no plastic deformation under 100 cycles of stretching), fast deformation recovery ability and excellent mechanical properties that are superior to the other tough PVA hydrogels, providing an effective way to optimize the mechanical properties of hydrogels for potential applications in artificial tendons and ligaments.
水凝胶广泛应用于组织工程、软体机器人和可穿戴电子设备中。然而，要同时实现所需的韧性和刚度却很困难，这严重阻碍了它们作为承重材料的应用。本研究提出了一种制备坚硬且坚韧的复合水凝胶的策略。在此，利用冷冻干燥和退火的协同效应，通过相分离、调节大分子链运动和促进大分子结晶，将柔性SiO纳米纤维（SNF）均匀分散在聚乙烯醇（PVA）基质中。当施加应力时，PVA和SNF之间强烈的分子相互作用有效地将负载损伤分散到基材上。冷冻干燥和退火处理的柔性SiO纳米纤维/聚乙烯醇（FDA-SNF/PVA）在增强的刚度（13.71±0.28兆帕）和韧性（9.9±0.4兆焦/平方米）之间达到了理想的平衡。此外，FDA-SNF/PVA水凝胶具有7.84±0.10兆帕的高拉伸强度、超弹性（在100次拉伸循环下无塑性变形）、快速变形恢复能力以及优于其他坚韧PVA水凝胶的优异机械性能，为优化水凝胶的机械性能以用于人造肌腱和韧带的潜在应用提供了一种有效方法。
