A novel synthesis of polymer brush on multiwall carbon nanotubes bearing terminal monomeric unit

A novel approach to fabricate polymer brushes on the surface of carbon nanotubes (CNTs) is proposed. Carboxyl groups on the surface of chemically oxidized CNTs were reacted with hexamethylene diisocyanate, followed by a reaction with methacrylamide to give terminal vinyl groups-functionalized CNTs, so called "CNT-mer." The synthetic procedure was investigated step-by-step and the synthesized CNT-mer was used to grow polystyrene (PS) from CNTs by a simple in situ polymerization in the presence of a thermal initiator. By employing ¹H NMR, X-ray photoelectron spectros-copy, thermogravimetric analysis, scanning electron microscopy, transmission electron microscopy, and light scattering, the experimental results were verified. Using this approach, 45% PS with respect to CNTs are grafted on the surface of CNTs with about 4.0 nm thickness. This novel technique would provide a facile route to prepare tailor-made polymer brushes on the surface of CNTs.