Enhanced lubrication and photothermal conversion via dynamically reversible supramolecular oil gels filled with MXene@mGLM composites

Herein, we have successfully fabricated supramolecular oil gels using a combination of MXene@mGLM composites and gelator 12-hydroxystearic acid (12-HSA) in base oil polyalphaolefin (PAO) through non-covalent bonding interactions. Initially, the MXene@mGLM composites were prepared by chemically bonding carbon quantum-encapsulated liquid metal (mGLM) onto MXene nanosheets through formation of catechol-metal complexes. Subsequently, the three-dimensional (3D) network structure formed by 12-HSA through non-covalent bonding interactions was filled with a mixture of MXene@mGLM and PAO to form a supramolecular oil gel. The experimental results demonstrate that the obtained MXene@mGLM gel displays dynamic reversibility and creep resistance resulting in a significant reduction in the friction coefficient (from 0.578 to 0.103) of the PAO gel, along with a marked decrease in wear volume by 70.4%. Furthermore, beyond its lubrication properties, the MXene@mGLM gel has excellent photothermal cycle stability, enabling efficient and rapid absorption of infrared light. Additionally, the MXene@mGLM gel can undergo reversible transformation from a gel state into a liquid state by exposure to infrared light.