Robust Self-Lubricating Material Constructed from Cross-Scale Graphene Oxide Hybrids and Lignocellulose

Wood-derived polymer matrix (WPM) can effectively replace traditional nondegradable petroleum-based products. Herein, the deep eutectic solvent made from choline chloride and oxalic acid induces the cleavage of lignin and the fibrillation of cellulose. These components can act as matrix and reinforcing fibers during the in situ regeneration of lignocellulose to create a robust WPM. Additionally, zero-dimensional Ag nanoparticles were mechanically anchored onto the surface of two-dimensional graphene oxide (GO). A polydopamine (PDA) layer was constructed to mediate the attraction and strong mechanical coupling between one-dimensional cellulose fibrils and GO-PDA/Ag, forming a cross-scale hybrid reinforcement network. The adhesion and aggregation of lignin on the hybrid network further confine the nanocomponents within the intertwined network, promoting their diffuse distribution. The friction and wear mechanisms of wood-based composites coupled with Al₂O₃ ceramic balls were thoroughly investigated. GO-PDA/Ag participates in tribo-chemical reactions at the interface during friction, forming a new transfer film that results in synergistic lubrication between Ag nanoparticles and GO. The multidimensional hybrid network can effectively transfer frictional stress and accelerate heat transfer, further enhancing the dissipation of frictional energy and improving the antifriction and antiwear performance of the WPM-GO-PDA/Ag composites.