Hydrophilic silica transformed silicone rubber into Superhydrophobic composites

Silicone rubber is widely used in medical and equipment manufacturing fields due to its excellent sealing and solvent resistance. However, the hydrophobicity of silicone rubber was unsatisfactory for many advanced engineering structures and applications. Generally, the preparation of artificial superhydrophobic materials suffered from either complicated in process or poor in environmental protection. Here, we reported a simple method to prepare silicone rubber composites with excellent superhydrophobic properties (water contact angle [WCA] = 155.2(degrees)) from low-cost hydrophilic silica. Tests showed that the uniform micro-nano structures were the key to the superhydrophobic properties of silicone rubber composites. The bounce test observed the rebound of water droplets with different initial velocities (0.77, 1, and 2 m/s) impacting silicone rubber surface, and verified the great advantages of silicone rubber modified by silica in hydrophobic. The modification method shown in this work provides a simple way to manufacture non-fluorinated, robustness superhydrophobic surfaces for a wide range of potential applications.Highlights Based on the improvement of micro-nano structure of the matrix surface by industrial silica, the preparation of superhydrophobic silicone rubber composites was realized. A process method for preparing fluorine-free superhydrophobic silicone rubber composites from hydrophilic silica was proposed. Stretchability and robustness were the key factors for successful superhydrophobic modification of silicone rubber elastomers.