Mussel inspired modification of carbon nanotubes using RAFT derived stimuli-responsive polymers

A novel strategy for surface modification of multi-walled carbon nanotubes (MWCNTs) using reversible addition fragmentation transfer (RAFT) derived pH- and thermo-responsive polymers was developed via a combination of mussel inspired chemistry and a Michael addition reaction. In this procedure, pristine MWCNTs were first coated with polydopamine through self polymerization of dopamine under alkine solution, and then RAFT derived stimuli-responsive polymers were further grafted onto PDA modified MWCNTs via a Michael addition reaction. The successful modification of MWCNTs was confirmed by a series of characterization techniques including transmission electron microscopy, Fourier transform infrared spectroscopy, Raman spectroscopy, thermal gravimetric analysis and X-ray photoelectron spectrometry. These polymer modified CNTs showed enhanced dispersibility in various solutions and pH-/temperature-responsive properties. Due to the strong adhesion of polydopamine to various materials surface, the method described in this work could also be extended to the surface modification of other nanomaterials.