A simple method to prepare superhydrophobic and regenerable antibacterial films

Abstract

Macromolecules incorporating N-halamines have shown significant antibacterial properties and can be regenerated by chlorination. In this work, a new type of regenerable material made of nano-sized latex particles having N-H groups was prepared via the emulsion polymerization of methacrylamide and dodecafluoroheptyl methacrylate with divinylbenzene as a crosslinker. The N-H moieties in this polymer were subsequently transformed into N-Cl groups by chlorination with an aqueous sodium hypochlorite solution, and films were prepared by casting on substrates previously coated with a self-adhesive silicone rubber. The nanoparticles and the films were characterized by Fourier transform infrared (FTIR) spectroscopy, x-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), contact angle measurements, scanning electron microscopy (SEM) and microbiological tests. The results showed that F and Cl were successfully incorporated in the nanoparticles, that the films were thermally stable and hydrophobic (with a contact angle of 152°), and that these materials exhibited antimicrobial properties. The N-Cl groups killed bacteria by releasing active chlorine as they transitioned to N-H groups, and could be re-chlorinated with a methanol solution of isocyanuric chloride. FTIR and XPS analyses confirmed this regeneration, while SEM image showed that the morphology of the original microspheres was maintained after re-chlorination. The re-chlorinated films also maintained superhydrophobic and bactericidal characteristics.

Recent Advances in Antibacterial Superhydrophobic Coatings

“…As a typical virus, it has research values and related research should be Reproduced with permission. [137] Copyright 2020, IOP Publishing Ltd.…”

“…Therefore, the produced antibacterial superhydrophobic fibrous membranes showed great potential application in food packaging and biomedical materials. Liang et al [ 137 ] prepared superhydrophobic and regenerable antibacterial coatings based on N ‐halamine ( Figure ). The prepared materials exhibited superhydrophobicity, high thermal stability, antibacterial, and antiadhesion properties.…”

“…Schematic diagram of a) fabrication process of the NPs and b) sterilization and regenerative process of the films. Reproduced with permission [137]. Copyright 2020, IOP Publishing Ltd.…”

Recent Advances in Dual‐Function Superhydrophobic Antibacterial Surfaces

“…[129] Incorporating N-halamines into macromolecules, Liang et al, created antibacterial films that were superhydrophobic, durable, and regenerable. [102] In their design, nanoscale microspheres were produced by copolymerizing divinylbenzene, dodecafluoroheptyl methacrylate, and N-halamine, subsequently chlorinating them with sodium hypochlorite. These microspheres could be spincoated onto substrates to form a superhydrophobic antibacterial film capable of killing bacteria by releasing active chlorine at a rate greater than 99.99%.…”