A rapid two-step electroless deposition process to fabricate superhydrophobic coatings on steel substrates

The present study reports a simple, highly effective, and safe two-step electroless deposition process for rapidly fabricating superhydrophobic Ag coatings on steel substrates. The steel plates were first immersed in the 1 mol/L aqueous CuSO4 solution for 20 s, and then immersed in the 0.03 mol/L aqueous AgNO3 solution containing 1 wt% fluoroalkylsilane (FAS) for 2 min. The sample surfaces were characterized by energy-dispersive x-ray spectroscopy, Fourier transform infrared spectrophotometry (FTIR), x-ray diffraction, scanning electron microscopy, step profiler, and optical contact angle measurements. The results show that, after the two-step electroless deposition process, the Ag coatings composed of the binary micro/nanometer-scale rough structures containing the FAS molecules with a low surface energy are formed on the steel surfaces. The as-prepared Ag coatings exhibit a good superhydrophobicity with a 163.4 +/- A 1.8A degrees water contact angle and 1.5 +/- A 0.5A degrees rolling angle.