In Situ Synthesis of h‐ BN @ SiO ₂ Micronano Hybrid Materials for Improved Tribological Performance in Phenolic Composites

Enhancing the wear resistance of phenolic laminated composites remains challenging due to poor filler dispersion and weak interfacial bonding. Here, we develop an h‐BN@SiO 2 micronano hybrid filler via alkaline etching of h‐BN followed by in situ hydrolysis‐condensation of tetraethyl orthosilicate, which uniformly anchors SiO 2 nanoparticles (23–60 nm) onto h‐BN surfaces through Si–O–B covalent bonds. The hybrid filler is incorporated into cotton fabric‐reinforced phenolic composites. At an optimal loading of 5 wt%, the composite reduces wear rate by 15% under dry sliding and 49% under water lubrication compared to h‐BN‐only modified composites. The enhanced performance arises from a synergistic effect: the chemically anchored SiO 2 not only prevents its own agglomeration but also strengthens filler‐matrix interlocking, while h‐BN provides interlayer sliding lubrication; together, they co‐form a robust transfer film that combines low shear resistance with high load‐bearing capacity, suppressing three‐body abrasive wear and stabilizing the friction interface. This in situ growth strategy offers a viable pathway for designing high‐dispersion hybrid nanofillers for polymer lubricating composites.