Scalable Functional Group Engineering of Carbon Nanotubes by Improved One-Step Nitrene Chemistry

A facile, green, low cost and efficient one-step technology to synthesize highly dispersible functional single-walled and multiwalled carbon nanotubes (f-SWNTs and f-MWNTs) up to supergrams is reported. Large-scale (up to hundreds of grams) synthesis of functional azides was developed at first, and various reactive groups (i.e., -OH, -NH2, -COOH, and -Br) were then introduced onto the convex surfaces of CNTs in merely one reaction of nitrene addition under a relatively mild condition without causing significant damage to nanotubes. The contents of the functional moieties can be easily controlled by adjusting the feed ratio of the azide compounds to CNTs. In order to demonstrate the reactivity and functions of the immobilized organic moieties, different chemical reactions, including surface-initiated polymerizations, amidation, and reduction of metal ions, were performed on the functional CNTs, affording various CNT-polymer and CNT-Pt nanohybrids. The resulting materials were characterized by various measurements, such as TGA, Raman, XPS, FTIR, NMR, XRD, SEM, TEM, and HRTEM. The presented one-step methodology opens the avenue for industrial production of functional CNTs.