Robust liquid-repellent coatings based on polymer nanoparticles with excellent self-cleaning and antibacterial performances

In this work, quaternary ammonium salt (QAS) functionalized fluorinated copolymer tethered hydroxyl groups were synthesized by free radical polymerization. And then novel liquid-repellent and antibacterial nanocomposite coatings were prepared via cross-linking the fluorinated copolymer and poly(urea-formaldehyde) nanoparticles (PUF NPs) containing active methylol groups with hexamethylene diisocyanate. The surface physical and chemical properties of the nanocomposite coating were systematically characterized by a series of measurements, demonstrating that the liquid-repellent surface with a dual hierarchical structure was obtained by the introduction of PUF NPs. The nanocomposite coating displayed superb self-cleaning and liquid-repellent properties, and could also maintain its superhydrophobicity even after 16 abrasion cycles and 20 cycles of cross-cut tape test. Moreover, the nanocomposite coating with over 0.11% surface concentration of N+ exhibited excellent antibacterial activity against Gram-negative Escherichia coli and Gram-positive Staphylococcus aureus. These results conclusively indicated that nanocomposite coatings had great promise for potential application in a wide range of practical fields.