Bridged h-BN Nanosheets Coatings: Simultaneous Shielding Atomic-Oxygen Irradiation and Achieving Superior Friction...

To confront extreme space environments, a combination of inorganic and organic coatings can provide a pathway for offering highly durable radiation resistance and anti-friction simultaneously. Herein, a strong interfacial 3D hydrogen-bonding network is designed to create robust hexagonal boron nitride (h-BN) based polymer coatings with excellent mechanical and friction performance after atomic oxygen (AO) irradiation. The h-BN-based polymer coatings possess substantial improvements in structural stability, thermal conductivity (5.75 W·m^-1·K^-1, 24 times higher than pure organic coatings), tensile strength (48.1 MPa, improved by ∼ 200%), and low friction (0.12-0.14, reduced by ∼ 2.5 times) after AO irradiation. Notably, the oxygen transmission rate decreases from 2.53 to 0.35 cm³·m^-2·24 h^-1, displaying superior oxygen substance barrier performance. This exceptional performance arises from h-BN providing dual physical and chemical barriers through its layered structure and chemical stability, effectively resisting AO irradiation. Additionally, the 3D network facilitates efficient load transfer and heat dissipation for coating structure stability because the concentrated load is instantly transmitted across the entire h-BN surface, and the high thermal conductivity of h-BN is exerted to prevent localized overheating. This work provides a design strategy for next-generation radiation-resistant materials that unify high thermal conductivity, robust mechanical and friction performance.