State Key Laboratory of Tribology , Tsinghua University , Beijing 100084 , China.
Tribology Research Institute, State Key Laboratory of Traction Power , Southwest Jiaotong University , Chengdu 610031 , China.
Langmuir. 2019 Sep 3;35(35):11452-11462. doi: 10.1021/acs.langmuir.9b01640. Epub 2019 Aug 22.
Graphene oxide (GO) has been evaluated as a multifunctional cross-linker or reinforcement agent in composite hydrogels. In this study, a nanocomposite hydrogel consisting of GO nanosheets and zwitterionic poly(sulfobetaine methacrylate) (PSBMA) was synthesized in an aqueous system via chemical and physical cross-linking effects. GO nanosheets were well dispersed in the hydrogels and effectively cross-linked into the sulfobetaine methacrylate (SBMA) polymer chains through the electrostatic interactions. The PSBMA hydrogel exhibited a significant enhancement in the compressive stress (close to a 5-fold increase) and a remarkable reduction in the coefficient of friction (COF) (corresponding to a decline of 52-76%) after the embedding of GO nanosheets. These improvements indicate the existence of synergetic interaction and good compatibility between GO nanosheets and the PSBMA hydrogel matrix, which results in an intertwined network structure with higher load-bearing capacity and better lubrication properties. This study provides potential in the development of new graphene-polymer composites, which is beneficial for cartilage replacement with high mechanical properties and excellent lubrication characteristics.
氧化石墨烯（GO）已被评估为复合水凝胶中的多功能交联剂或增强剂。在这项研究中，通过化学和物理交联作用，在水溶液中合成了由 GO 纳米片和两性离子聚（磺基甜菜碱甲基丙烯酸酯）（PSBMA）组成的纳米复合水凝胶。GO 纳米片在水凝胶中得到了很好的分散，并通过静电相互作用有效地交联到磺基甜菜碱甲基丙烯酸酯（SBMA）聚合物链中。PSBMA 水凝胶在嵌入 GO 纳米片后，抗压强度显著提高（接近 5 倍），摩擦系数（COF）显著降低（相应下降 52-76%）。这些改进表明 GO 纳米片和 PSBMA 水凝胶基质之间存在协同相互作用和良好的相容性，从而形成具有更高承载能力和更好润滑性能的交织网络结构。这项研究为开发新型石墨烯-聚合物复合材料提供了潜力，有利于具有高机械性能和优异润滑特性的软骨替代。
