Novel nanostructured and antimicrobial PVDF-HFP/PVP/MoO₃ composite

Contact surfaces represent a liability for the transmission of microbial contamination, leading to high consumption of detergents and biocides for their care and further increasing the already problematic antimicrobial resistance of microorganisms. This issue could be addressed by the use of antimicrobial nanocomposite coatings. In this research, a polymer nanocomposite of inert poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) and water-soluble polyvinylpyrrolidone (PVP) polymers with molybdenum trioxide (MoO₃) nanowires (NWs) was designed and characterised for to its surface properties and antimicrobial potential. The nanocomposite has an inhomogeneous structure with a positively charged and hydrophilic surface. The nanofiller reduces the surface roughness, changes the zeta potential from negative to positive, increases the wetting angle and thermal stability of the blend and maintains the polar β-phase in PVDF-HFP. The high specific surface area of the NWs leads to rapid release into water and causes pH decrease, followed by hydrolysis of PVP polymer and formation of carboxyl acid and ammonium salt. The antimicrobial activity of the nanocomposite inactivates both bacteria and fungi, indicating that the novel nanocomposite is a stable nanostructured coating unfavourable for microorganism colonisation. The antimicrobial activity of this nanocomposite is activated by water, which makes it an intriguing candidate for antimicrobial coating of contact surfaces.