Imidazolium salts grafted on cotton fibres for long-term antimicrobial activity

New antimicrobial (AM) coatings based on imidazolium salts have been prepared linking the imidazolium salts to the cotton fabric using siloxane oligomers as coupling agents. Three different imidazolium salts, linked to the siloxane oligomers connected to the cotton fabric either with ionic or covalent linkages, have been used. FTIR analysis shows that the imidazolium salts are linked to the cotton fabric. All the coatings prepared have high antimicrobial activity at both concentrations tested (3 and 10 wt%) and against a Gram positive and a Gram negative bacterium. The AM activity is mainly retained after 4 cycles of washing.