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Abstract
Compounds based upon aldehyde functionalities or long chain quaternary ammonium functionalities constitute two major classes of antimicrobial materials. The antibacterial activities of these two classes of compounds were evaluated in the unbound (free compound) aqueous suspension and in the bound surface-treated cotton textile against E. coli. After a one hour incubation, the minimum lethal concentration of AEM 5700, a commercially available quaternary ammonium functional silane from Aegis Environments, was found to be 84 mg/g in the deionized water. The salinity of the test media significantly affected the antibacterial activity of AEM 5700 free compound. The minimum lethal concentration was increased to 8000 mg/g in the artificial seawater. Inactivation against E. coli of either free butyraldehyde or undecanylaldehyde functional triethoxysilylane in the deionized water was not observed. Cotton textile treated with various concentrations of AEM 5700 showed a two-stage antibacterial behavior when immersed in the deionized water. The higher activity in the first stage was due to the combined action of the leachate and the surface-bound AEM 5700, whereas the activity in the second-stage was caused by the contact between the surface-bound AEM 5700 and E. coli. This analysis was confirmed when the AEM 5700 treated cotton textile was tested in the artificial seawater. The leachate in the artificial seawater had no activity. The first-stage antibacterial behavior was not observed. Only the contact between the surfacebound AEM 5700 and E. coli contributed to about a one log reduction plateau with time. For cotton textile treated by either of the examined trialkoxysilylaldehyde compounds, inactivation against E. coli was not found.
Keywords
Antibacterial activities, surface-bound biocide, trialkoxysilyl compound
Transmission of infectious pathogens by surface contact is a growing concern to medical providers and the public health. The design of the antimicrobial textile is a feasible approach to protect the spread of pathogens in a variety of applications such as in the health care facilities, textiles and buildings. The demand for antimicrobial textiles has grown considerably recently. The production of the antimicrobial textile was 100,000 tonnes worldwide in 2000, and was one of the fastest growing sectors of the textile market in Western Europe between 2001 and 2005.1
The design of antimicrobial surfaces including the light-activated surface, surface with releasing antimicrobial agent and surface by contact inactivation...