Mussel-inspired chemistry for preparation of superhydrophobic surfaces on porous substrates

A facile and versatile mussel-inspired surface modification approach was used to modify porous materials (wood, sponge and stainless steel mesh) to fabricate a superhydrophobic surface. The as-formed polydopamine (PDA) coating can tightly adhere on the porous structure surface, which also provides a versatile platform for secondary reactions to anchor hydrophobic long-chain groups for hierarchical superhydrophobic surfaces preparation. The as-prepared surfaces showed excellent superhydrophobicity with a water contact angle (CA) of about 153 degrees, even after being subjected to harsh conditions, including strong acid-base and organic solvent immersion, high-temperature boiling, ultrasonic washing, and ultraviolet aging. The produced superhydrophobic sponge exhibited an oil absorption capacity of 73-156 times its own weight for a series of oils and organic solvents and showed good recyclability. The obtained stainless steel mesh also presented good oil-water separation ability. Importantly, this modification method provides an efficient, versatile, easy, and mild route to prepare superhydrophobic surfaces for various porous substrates, resulting in a wide range of potential applications.