New ultra-transparent, hard and antibacterial coating
Pathogenic microbes are ubiquitous, and they can proliferate quickly on wood surface under the suitable conditions to pose a huge hidden threat to public health security and safety. To impart wood surface with outstanding antibacterial activity, researchers have synthesised a pyridine quaternary ammonium (PQAS) monomer, and then prepared the cationic antibacterial polymer (CAP) by radical copolymerization. After that, the antibacterial composite emulsion was obtained after uniformly mixing CAP with a commercialized polyacrylate emulsion (PAE). Finally, the researchers obtained an ultra-transparent, hard and antibacterial CAP/PAE coating by brushing CAP/PAE emulsion on the wood surface and then drying at 80 °C for 3 h.
Antibacterial activity
The experimental results indicated that the antibacterial activity of CAP/PAE coating against E. coli and S. aureus were greater than 99.9 % without releasing antibacterial components. Even after being irradiated with ultraviolet light at 254 nm for 100 h, its antibacterial rates still reached 97.12 % (E. coli) and 99.35 % (S. aureus), respectively, which are much higher than the required antibacterial rate of Grade 1 (the highest-grade), and superior to most of the reported work. In addition, the CAP/PAE coating exhibited 5H hardness, ultra-transparent, enhanced mechanical properties and low cytotoxicity.
The study has been published in Progress in Organic Coatings, Volume 175, February 2023.