A multifunctional superhydrophobic coating with efficient anti-adhesion and synergistic antibacterial properties

Bacterial adhesion and colonization on the surface present a public health concern worldwide. To address this concern, surfaces are endowed with the ability to resist bacterial adhesion to surfaces and eliminate bacteria. In this study, a multifunctional superhydrophobic antibacterial surface is prepared by combining two composite fillers obtained by in-situ growth of silica nanoparticles on palygorskite via sol-gel and modified by a low surface energy substance and by in-situ reduction of silver nanoparticles via tannic acid and thus adhering to the palygorskite and modified by the low surface energy substance, reducing bacterial adhesion and survival in multiple ways. Firstly, the complex nano/micro structures and low surface energy of the superhydrophobic surface hinder protein adhesion and bacterial adhesion on the surface. Secondly, the sharp surfaces constructed by the nanofibers disrupt bacterial cell integrity, providing physical antibacterial action. Thirdly, the coating releases silver ions and reactive oxygen species, which are produced by silver nanoparticles, to chemically damage bacteria. Through the synergy of superhydrophobic surface and silver nanoparticles, the coating achieves good resistance to bacterial adhesion and is able to eliminate Escherichia coli (100.0 ± 0.1 %) and Staphylococcus aureus (99.8 ± 0.1 %). The coating also exhibits good mechanical properties, with silver ions still being released after 100 cycles of wear test. With its unique self-cleaning, anti-adhesive, anti-corrosion, robust mechanical properties, and antibacterial capabilities, the superhydrophobic coating holds a promising application prospect.