MXene possesses great potential in enriching the functionalities of hydrogels due to its unique metallic conductivity, high aspect ratio, near-infrared light (NIR light) responsiveness, and wide tunability, however, the poor compatibility of MXene with hydrogels limits further applications. In this work, we report a uniformly dispersed MXene-functionalized poly-N-isopropylacrylamide (PNIPAM)/poly-2-acrylamido-2-methyl-1-propanesulfonic acid (PAMPS) double network hydrogel (M—DN hydrogel) that can achieve switchable friction regulation by using the NIR light. The dispersity of MXene in hydrogels was significantly improved by incorporating the chitosan (CS) polymer. This M—DN hydrogel showed much low coefficient of friction (COF) at 25 °C due to the presence of hydration layer on hydrogel surface. After illuminating with the NIR light, M—DN hydrogel with good photothermal effect rapidly raised the temperature to above the lower critical solution temperature (LCST), which led to an obvious increase of surface COF owing to the destruction of the hydration layer. In addition, M—DN friction control hydrogel showed good recyclability and controllability by tuning “on-off” of the NIR light. This work highlights the construction of functional MXene hydrogels for intelligent lubrication, which provides insight for interface sensing, controlled transmission, and flexible robotic arms.

MXene由于其独特的金属导电性、高纵横比、近红外光（NIR光）响应性和广泛的可调性而在丰富水凝胶的功能方面具有巨大的潜力，然而，MXene与水凝胶的相容性差限制了进一步的应用。在这项工作中，我们报道了一种均匀分散的MXene功能化聚-N-异丙基丙烯酰胺（PNIPAM）/聚-2-丙烯酰胺-2-甲基-1-丙磺酸（PAMPS）双网络水凝胶（M-DN水凝胶），可以实现使用近红外光进行可切换的摩擦调节。通过掺入壳聚糖（CS）聚合物，MXene 在水凝胶中的分散性得到显着改善。由于水凝胶表面存在水化层，这种 M-DN 水凝胶在 25 °C 下表现出极低的摩擦系数 (COF)。用近红外光照射后，具有良好光热效应的M-DN水凝胶迅速将温度升高至下临界溶液温度（LCST）以上，由于水化层的破坏导致表面COF明显增加。此外，M-DN摩擦控制水凝胶通过调节近红外光的“开关”表现出良好的可回收性和可控性。这项工作重点介绍了用于智能润滑的功能性 MXene 水凝胶的构建，为界面传感、受控传输和灵活的机械臂提供了见解。通过调节近红外光的“开关”，M-DN摩擦控制水凝胶表现出良好的可回收性和可控性。这项工作重点介绍了用于智能润滑的功能性 MXene 水凝胶的构建，为界面传感、受控传输和灵活的机械臂提供了见解。通过调节近红外光的“开关”，M-DN摩擦控制水凝胶表现出良好的可回收性和可控性。这项工作重点介绍了用于智能润滑的功能性 MXene 水凝胶的构建，为界面传感、受控传输和灵活的机械臂提供了见解。