Manipulation of surface properties and long-term antibacterial performance of composite films via alkyl side chain engineering

Construction of long-term antibacterial surfaces is highly challengeable but of great academic and social significance. Herein, a strategy integrating the foulant-release property with synergistically bactericidal action is designed to endow the surfaces with long-term antibacterial ability. To fulfill this design principle, quaternized fluoropolymer/Ag composite films (FP-Qx/Ag CFs) were conveniently fabricated via sequential miniemulsion polymerization and squeegeeing techniques. The crucial effect of the alkyl chain length of quaternary ammonium (QA) units on the particle properties and antibacterial ability of quaternized fluoropolymer/Ag nanocomposite particles (FP-Qx/Ag NCPs), as well as the surface properties, surface energy, underwater surface reconstruction, and antibacterial ability of FP-Qx/Ag CFs was disclosed. The long-term antibacterial performance of the FP-Qx/Ag CFs against both regular and multi-drug resistant bacteria depended on the alkyl chain length of QA units. The respective role of surface energy and surface rearrangement, as well as the synergistic bactericidal ability of FP-Qx/Ag CFs that could be manipulated by the alkyl chain length of QA units in the long-term antibacterial performance was decoupled to propose a comprehensive long-term antibacterial mechanism. Our work may guide the design of long-term antibacterial surfaces and provide an effective method to manipulate the property and performance of antibacterial surfaces via alkyl side chain engineering.