Rigid-flexible UiO66-NH₂/carboxymethyl cellulose hierarchical interface for enhanced load-bearing capacity and adaptive wear resistance of carbon fabric composites

Carbon fabric (CF)-reinforced polymer composites show great potential in wet friction applications, but their performance is severely limited by poor interfacial adhesion and susceptibility to abrasive wear. Herein, we propose a “rigid-flexible” hierarchical interface strategy utilizing a conformal defect-filling carboxymethyl cellulose (CMC) layer and an in-situ grown rigid UiO66-NH₂ octahedral array to enhance the mechanical and tribological properties of CF/phenolic composites. The CMC/UiO66-NH2 hierarchical modification reduced surface defects and increased the apparent single-fiber tensile strength by 89.3%. Meanwhile, the UiO66-NH₂ array increased the surface roughness and promoted mechanical interlocking with the resin matrix. The combined CMC/UiO66-NH₂ interface improved interfacial load transfer and reduced premature debonding, leading to a 75.1% increase in tensile strength. Furthermore, under alternating friction shear, the hierarchical interface promotes the formation of a protective tribofilm, promoting the in-situ formation of a continuous solid tribofilm. This transitions the wear mechanism from severe abrasive wear to mild sliding wear, resulting in an 81.1% reduction in the specific wear rate. This study provides an interfacial design strategy for designing high-load-bearing and highly durable fabric composites for demanding tribological applications.