Fabrication of superhydrophobic coatings for combating bacterial colonization on Al with relevance to marine and medical applications

Aluminum and its alloys are widely used in almost all industries and for marine and medical applications. However, their surfaces are easily colonized by bacteria that form biofilms and corroded by chemical reactions. We report here a simple method to fabricate polyaniline/chitosan/zinc stearate superhydrophobic coatings on aluminum with a micro-nanosurface structure by polymerization of aniline and deposition of chitosan and zinc stearate coating. The fabricated coatings have been characterized by ATR-IR, XRD, FE-SEM, and EDX. The superhydrophobic surface shows the highest water-repellent property with contact angle of 150.7 degrees, which is responsible for antiadhesion of bacteria, antiicing property, and excellent corrosion resistance of aluminum. The corrosion behavior of the coating in the 3.5% NaCl solution was investigated by EIS and potentiodynamic polarization. The efficacies of the different coatings against bacteria that are commonly encountered in marine (Desulfovibrio desulfuricans) and medical applications (Staphylococcus aureus and Escherichia coli) are demonstrated.