Construction of silicone with quaternized hydantoin‐based N‐chloramines on cotton with aid of supercritical interpenetration for antibacterial synergism

Abstract

AbstractA silicone carrying combined functionalities of different mechanisms and physiochemical properties is synthesized as a strategy for faster and broader bacterial eliminations. Briefly, ring‐opening alcoholysis of succinic anhydride with 2‐dimethylaminoethanol and subsequent esterification of the alcoholysis product with 5‐(4‐hydroxyphenyl)imidazolidine‐2,4‐dione produced a structure with one tertiary amine and two hydantoinyl NH bonds. The tertiary amine was quaternized with 3‐chloro‐1‐propanol whose OH was then alcoholyzed with SiH of poly(methylhydrosiloxane). The polymeric product was interpenetrated into cotton at 30 MPa and 50°C in supercritical CO2 and treated with tert‐butyl hypochlorite to chlorinate its hydantoinyl NH bonds, forming a 78 nm biocidal layer of silicone with quaternized hydantoin‐based N‐chloramines. Antibacterial tests showed that the quaternary ammonium salt and two hydantoin‐based N‐chloramines act synergistically due to their complementary features, killing both Staphylococcus aureus and Escherichia coli much more efficiently than each functionality. More importantly, the ratio of N‐chloramine to quaternary ammonium salt of 2:1 herein also provided higher efficacy than a reported counterpart with a 1:1 ratio. Biocidability of the modified cotton had promising stability and rechargeability, which indicates that supercritical interpenetration produced a durable interfacial layer without the necessity of chemical bonding.