Pan Xiaofeng, Pan Jiawei, Li Xiang, Wang Zhongkai, Ni Yonghao, Wang Qinhua
Anhui Provincial Engineering Center for High-Performance Biobased Nylons, School of Materials and Chemistry, Anhui Agricultural University, Hefei, Anhui, 230036, P. R. China.
National Forestry and Grassland Administration Key Laboratory of Plant Fiber Functional Materials, College of Material Engineering, Fujian Agriculture and Forestry University, Fuzhou, Fujian, 350108, P. R. China.
Adv Mater. 2024 Sep;36(36):e2406671. doi: 10.1002/adma.202406671. Epub 2024 Jul 10.
Supramolecular hydrogels are typically assembled through weak non-covalent interactions, posing a significant challenge in achieving ultra strength. Developing a higher strength based on molecular/nanoscale engineering concepts is a potential improvement strategy. Herein, a super-tough supramolecular hydrogel is assembled by gradually diffusing lignosulfonate sodium (LS) into a polyvinyl alcohol (PVA) solution. Both simulations and analytical results indicate that the assembly and subsequent enhancement of the crosslinked network are primarily attributed to LS-induced formation and gradual densification of strong crystalline domains within the hydrogel. The optimized hydrogel exhibits impressive mechanical properties with tensile strength of ≈20 MPa, Young's modulus of ≈14 MPa, and toughness of ≈50 MJ m⁻, making it the strongest lignin-PVA/polymer hydrogel known so far. Moreover, LS provides the supramolecular hydrogel with excellent low-temperature stability (<-60 °C), antibacterial, and UV-blocking capability (≈100%). Interestingly, the diffusion ability of LS is demonstrated for self-restructuring damaged supramolecular hydrogel, achieving 3D patterning on hydrogel surfaces, and enhancing the local strength of the freeze-thaw PVA hydrogel. The goal is to foster a versatile hydrogel platform by combining eco-friendly LS with biocompatible PVA, paving the way for innovation and interdisciplinarity in biomedicine, engineering materials, and forestry science.
超分子水凝胶通常通过弱非共价相互作用组装而成，这在实现超强强度方面构成了重大挑战。基于分子/纳米尺度工程概念开发更高强度是一种潜在的改进策略。在此，通过将木质素磺酸钠（LS）逐渐扩散到聚乙烯醇（PVA）溶液中来组装一种超韧性超分子水凝胶。模拟和分析结果均表明，交联网络的组装及随后的增强主要归因于LS诱导水凝胶内强结晶域的形成和逐渐致密化。优化后的水凝胶表现出令人印象深刻的机械性能，拉伸强度约为20MPa，杨氏模量约为14MPa，韧性约为50MJ m⁻³，使其成为迄今为止已知最强的木质素-PVA/聚合物水凝胶。此外，LS赋予超分子水凝胶优异的低温稳定性（<-60°C）、抗菌和紫外线阻挡能力（约100%）。有趣的是，展示了LS的扩散能力可用于自我修复受损的超分子水凝胶，在水凝胶表面实现3D图案化，并增强冻融PVA水凝胶的局部强度。目标是通过将环保的LS与生物相容性PVA相结合，培育一个多功能水凝胶平台，为生物医学、工程材料和林业科学的创新与跨学科发展铺平道路。
