Preparation of stable superhydrophobic film on stainless steel substrate by a combined approach using electrodeposition and fluorinated modification

A combined electrodeposition and fluorinated modification approach for preparation of stable superhydrophobic film on SS316L substrate is presented. Nickel film with micro-nano binary structure was coated on the substrate using electrodeposition techniques and then followed by a fluorinated modification process to obtain superhydrophobic surface. The surface morphology of the nickel film at micro/nano scale was characterized at different electrodeposition current densities. Results show that when the current density fall in the range from 5 to 9 A/dm2, the contact angle with 5 μL water droplets on the nickel film after fluorinated modification is higher than 160°, and the sliding angle with 10 μL water droplets is as low as 1°. Moreover, the superhydrophobic film has a very low contact angle hysteresis of 2.2°. Results also show that the superhydrophobic nickel film on SS316L has satisfied stability both in strong acid and alkaline solutions, and the superhydrophobic property can still keep fairly well after a durability testing last for more than 400 days under ambient conditions.