Antimicrobial properties of novel n-halamine siloxane coatings

Abstract

Antimicrobial coatings on a wide variety of hard and soft substrates were prepared by exposing surfaces treated with novel N-halamine siloxane precursor monomers and macro-monomers to oxidative halogen solutions. Suspensions of a range of bacterial, viral, fungal and yeast micro-organisms were applied to the halogen-charged coatings for defined intervals, before recovery and quantification of surviving microbes using appropriate neutralisation and culture techniques. The biocidal surfaces exhibited powerful, broad-spectrum antimicrobial properties, inactivating most challenge microbes in contact times measured in minutes to hours, rather than the extended contact incubation periods usually associated with substrate-bound antimicrobial agents. Antimicrobial effects were also demonstrated to prevent odour caused by bacterial generation of ammonia in an experimental simulation of a urine-soaked nappy pad. Contact times for efficacy were related to bound halogen concentrations per unit of surface area. Potential benefits of these novel rechargeable biocidal surfaces cover a range, from limiting contamination of environmental surfaces with disease agents in healthcare or food service facilities, to controlling odour and mildew in bathrooms, and preventing odour formation in incontinence pads. They also confer antimicrobial protective functions on textiles and non-woven filter media for air and water.