Effective poly(ethylene glycol) methyl ether grafting technique onto Nylon 6 surface to achieve resistance against pathogenic bacteria Staphylococcus aureus and Pseudomonas aeruginosa

Our study is focused on an efficient reduction of amide functional groups to secondary amine on Nylon 6 surface with borane–tetrahydrofuran (BH3–THF) complex, followed by N-alkylation with benzyl chloride (C6H5CH2Cl) which has been successfully used as a model system for further grafting of the reduced Nylon 6 surface by poly(ethylene glycol) methyl ether tosylate (Me-PEG-OTs). The amine-activated surface has been obtained by treatment of reduced Nylon 6 with n-butyllithium or tert-butyllithium in THF. Modified Nylon 6 has been found to be antibacterial particularly due to the presence of hydrophilic poly(ethylene glycol) methyl ether (H3C-PEG) chains. The surface modifications were successfully characterized by various techniques. Water contact angle and free surface energy analyses indicated a significant change in the surface morphology. It was further supported by scanning electron microscopy, atomic force microscopy, X-ray photoelectron spectroscopy, Fourier-transform infrared spectroscopy and Raman spectroscopy. Finally, antibacterial tests were performed against two pathogenic bacterial strains Pseudomonas aeruginosa (CCM 3955) and Staphylococcus aureus (CCM 3953).