Microwave-assisted poly(glycidyl methacrylate)-functionalized multiwall carbon nanotubes with a ‘tendrillar’ nanofibrous polyaniline wrapping and their interaction at bio-interface

Abstract

Multiwall carbon nanotubes (MWCNTs) were activated by microwave irradiation and covalently functionalized with poly(glycidyl methacrylate) (PGMA) through free radical polymerization using ‘fishing process’ when the propagating polymer radicals were attached onto the graphitic surface of the nanotube. The PGMA-functionalized MWCNTs were then used as a precursor to non-covalently wrap polyaniline (PAni) nanofiber onto them. The functionalized nanotubes exhibited stable dispersion up to 180days in tetrahydrofuran, dimethyl formamide and dimethyl sulfoxide. Fourier transform infrared analyses indicated the attachment of the epoxide and benzenoid–quinoid functional moieties onto the nanotube surface. The PGMA coating on the nanotube and surrounding PAni nanofiber on the MWCNT scaffold were confirmed by transmission electron microscopy. The Raman spectroscopy confirmed the phonon-assisted modification of the nanotube. The differential action of the pristine and functionalized MWCNTs against an opportunistic bacterium (Escherichiacoli ) and its plasmid deoxyribonucleic acid was also investigated. Pristine nanotubes exhibited bacterial inhibitory action and no condensation with the pET-32α(+) plasmid. On the other hand, the anti-bacterial PAni nanofiber and functionalized nanotubes showed complex formation with the bacterial plasmid.