Antibacterial Mesoporous Silica Granules Containing a Stable N-Halamine Moiety.

High-efficacy and regenerable antimicrobial silica granules were prepared via oxa-Michael addition between poly(vinyl alcohol) (PVA) and methylene-bis-acrylamide (MBA) under the catalysis of sodium carbonate in an aqueous solution. Diluted water glass was added, and the solution pH was adjusted to about 7 to precipitate PVA-MBA modified mesoporous silica (PVA-MBA@SiO) granules. N-Halamine-grafted silica (PVA-MBA-Cl@SiO) granules were achieved by adding diluted sodium hypochlorite solution. It was found that a BET surface area of about 380 m g for PVA-MBA@SiO granules and a Cl% of about 3.80% for PVA-MBA-Cl@SiO granules could be achieved under optimized preparation conditions. Antimicrobial tests showed that the as-prepared antimicrobial silica granules were capable of about a 6-log inactivation of and O157:H7 within 10 min of contact. Furthermore, the as-prepared antimicrobial silica granules can be recycled many times due to the excellent regenerability of their N-halamine functional groups and can be saved for a long time. With the above-mentioned advantages, the granules have potential applications in water disinfection.