MOE Key Laboratory of Macromolecular Synthesis and Functionalization, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, China.
ACS Appl Mater Interfaces. 2021 Sep 8;13(35):42240-42249. doi: 10.1021/acsami.1c12631. Epub 2021 Aug 26.
Although hydrogels exhibit excellent low frictional behavior, their friction coefficients cannot meet the requirements for biology, especially at low sliding velocities. Inspired by the natural lubrication mechanism from animals, plants, or even microorganisms, a nonionic surfactant, Tween 80, was introduced into a biofriendly poly(vinyl alcohol) (PVA) hydrogel to construct a composite hydrogel with ultralubrication. Such a combination endows PVA hydrogels with an ultralow coefficient of friction (10 to 10) under an extremely low sliding velocity (0.01 mm/s). Tween 80 micelles and aggregates, together with hydrophobic molds, induce rough surfaces and high carbon contents on the surface of the hydrogel, promoting excellent lubrication behavior of the composite hydrogel. In addition to the desirable lubrication, this environmentally friendly composite hydrogel also exhibited excellent flexibility at subzero temperatures, tensile properties, and good recyclability. Additionally, the method of introducing Tween 80 into hydrogels to reduce friction is also effective in chemically crosslinked double-network hydrogels.
尽管水凝胶表现出优异的低摩擦性能，但它们的摩擦系数仍无法满足生物学的要求，尤其是在低滑动速度下。受动物、植物甚至微生物的自然润滑机制的启发，将非离子表面活性剂吐温 80 引入生物友好型聚乙烯醇 (PVA) 水凝胶中，构建具有超润滑性能的复合水凝胶。这种组合使 PVA 水凝胶在极低的滑动速度（0.01mm/s）下具有超低的摩擦系数（10^-10）。吐温 80 胶束和聚集体，以及疏水性模具，在水凝胶表面诱导出粗糙表面和高碳含量，从而促进了复合水凝胶的优异润滑性能。除了理想的润滑性，这种环保型复合水凝胶在亚低温下还表现出优异的柔韧性、拉伸性能和良好的可回收性。此外，将吐温 80 引入水凝胶以降低摩擦的方法在化学交联的双网络水凝胶中也同样有效。
