Antimold Activities Using Quaternized Epoxy-Based Polymer Monoliths

Abstract

Monolithic materials having 3D-network structure are now widely used for the separation such in liquid chromatography and solid-phase extraction. Additionally, monolithic materials showed several functionalities, we previously discovered that epoxy monoliths, which were prepared with epoxy compounds and amine curing agents using suitable porogens, showed antibacterial potency when quaternized by hydrogen halides and alkyl halides and immersed in coli suspension. Antibacterial activity was enhanced by lowering pH of the aqueous phase with the former and cell membrane disruption triggered by cell contact with the latter. As well as the epoxy monoliths with nitrogen (N) at the high content rate enhance antibacterial activity. We consider that these actions may be effective for molds. In this study, we synthesize epoxy monoliths, conducting quaternization with hydrochloric acid and butyl bromide. Alternaria alternate, one of the genera in sooty mold, is employed for an evaluation. We examine effects of the epoxy monoliths on spores and hyphal growth. With the effects on spores, unquaternized monoliths and ones quaternized with hydrochloric acid and/or butyl bromide were immersed in coli suspension, and after predetermined time, the suspension was cultured in potato dextrose agar. Consequently, the monoliths quaternized with butyl bromide inhibited the growth of the spores. With the effects on the hyphal growth, we observed mold growth by placing the fabricated epoxy monolith in PDA and injecting molds to the surface of the monolith. The monoliths quaternized with hydrochloric acid inhibited the hyphal growth most by lowering pH of the culture medium. The quaternized monoliths with butyl bromide could inhibit the hyphal growth due to the positively charged surface of the monolith. Besides, we successfully achieved antimold with inhibiting the fungal growth by raising the N content rate and increasing degree of quaternization.