Hierarchical Interfaces in Epoxy Composites for Superhydrophobicity and Anti‐Icing

ABSTRACT Epoxy‐based materials are widely used in protective coatings and structural composites. However, the water absorption and interface performance degradation caused by long‐term exposure to humid environments still limit the stability of their service life. This paper proposes a dual‐scale interface control strategy for silicone rubber‐derived powder (SR‐Powder) and constructs an E‐44 epoxy composite surface with superhydrophobic and freezing‐delay properties. The incorporation of SR‐Powder enhanced the tensile strength of the representative epoxy composite formulation. A hierarchical surface structure was further constructed by imprint‐assisted deposition using a 200‐mesh sieve. The water contact angle of the obtained epoxy composites reached 159.9°, and the sliding angle and contact angle hysteresis decreased to 3.9° and 3.8°, respectively. At −15°C, the freezing delay time of this surface reached 359.0 s, which was 372.4% higher than that of pure epoxy. Molecular dynamics simulations indicate that SR‐Powder weakens the interaction between water molecules and the epoxy interface, reduces the diffusion ability of interface water molecules, and provides a molecular‐scale basis for the low adhesion and water‐repellent mechanism of the composite surface. This study provides a pathway for the functional utilization of silicone rubber‐derived powder and the design of high‐performance water‐repellent epoxy materials.