Enhanced antibacterial activity and hydrophobicity in coatings based on polyvinylidene fluoride and carbon nanoparticles

Abstract Nanocomposite coatings based on polyvinylidene fluoride (PVDF) and carbon nanoparticles (nano‐carbon) were prepared via spraying. The influence of nano‐carbon loading has been examined; however, the preparation method notably affects the properties of the coatings. A diverse array of hydrophobic and antibacterial properties was successfully achieved by employing the PVDF/nano‐carbon system through either a one‐step or two‐step approach. In the one‐step approach, PVDF and nano‐carbon were mixed and applied together. In contrast, the two‐step method first entails applying a PVDF sublayer, followed by the deposition of a nano‐carbon layer. The one‐step process results in a single‐layer coating, while the two‐step process yields a dual‐layer coating system. The two‐step approach significantly improved hydrophobicity due to the notable aggregation of nano‐carbon within the surface layer. A true superhydrophobic property was achieved (WCA = 157° and SA ~ 2°) by using 20% nano‐carbon in a two‐step process at a drying temperature of 200°C. The bacterial adhesion study indicated varying antibacterial efficacy among the coatings, with the superhydrophobic coating achieving the highest rate of 99.3%. Implementing this coating strategy in healthcare and food‐contact applications can substantially reduce contamination risks. Highlights PVDF/nano‐carbon coatings with varying degrees of hydrophobicity were fabricated. High‐temperature drying was used to fabricate more stable coatings. The two‐step method led to higher hydrophobicity than the one‐step method. Superhydrophobicity was key to achieving high antibacterial rates (99.3%). The surface localization of nano‐carbon governed the coatings' performance.