Beijing Engineering Research Center of Cellulose and Its Derivatives, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Beijing Engineering Research Center of Cellulose and Its Derivatives, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing, 100081, China.
Carbohydr Polym. 2018 Aug 1;193:73-81. doi: 10.1016/j.carbpol.2018.03.086. Epub 2018 Mar 27.
To develop healable hydrogels with excellent mechanical properties is still a challenge topic. In this study, a novel class of physically crosslinked polyacrylamide based nanocomposite hydrogels reinforced with cellulose nanofibers (CNF) were fabricated using radical polymerization, followed by further strengthening through ferric ions via strong ionic coordination interactions between Fe and carboxyls on CNF surfaces. Then the obtained gels were characterized by FTIR, tensile and compressive measurements as well as healing experiments. The increase of CNF amount or Fe concentration generated positive effect on the improvement of hydrogel mechanics, demonstrating facilely modulatable mechanical properties through simply changing CNF dosages in formulations and/or Fe concentrations in posttreatment. The obtained nanocomposite hydrogels show remarkable mechanical properties with high stiffness and toughness, quick recovery and healing abilities owing to the distinctive roles of dual physical crosslinks. This work provides a promising view for designing novel high strength hydrogels with fully physical crosslinks.
开发具有优异机械性能的可修复水凝胶仍然是一个具有挑战性的课题。在本研究中，使用自由基聚合制备了一类新型的物理交联的基于聚丙烯酰胺的纳米复合水凝胶，该水凝胶通过纤维素纳米纤维（CNF）增强，然后通过铁离子进一步增强，这是通过 CNF 表面的 Fe 和羧基之间的强离子配位相互作用实现的。然后通过傅里叶变换红外光谱（FTIR）、拉伸和压缩测试以及愈合实验对所得凝胶进行了表征。增加 CNF 用量或 Fe 浓度对提高水凝胶力学性能有积极影响，表明通过简单地改变配方中的 CNF 用量和/或后处理中的 Fe 浓度，可轻松调节机械性能。所得纳米复合水凝胶具有高刚度和韧性、快速恢复和愈合能力，这归因于双重物理交联的独特作用。这项工作为设计具有完全物理交联的新型高强度水凝胶提供了有前景的思路。
