Silylation of Single-Walled Carbon Nanotubes

Herein we present, to the best of our knowledge, the first report of effective silylation of raw, pristine single-walled carbon nanotubes (SWNTs). Specifically, commercially available CoMoCAT SWNTs were functionalized at their ends and sidewalls (a) with trimethoxysilane and in a separate experiment, (b) with hexaphenyldisilane. Raman analyses demonstrated selective reactivity of predominantly smaller-diameter semiconducting nanotubes. High-resolution transmission electron microscopy (HRTEM), scanning electron microscopy, and atomic force microscopy showed that the functionalization reaction was structurally nondestructive to the tube integrity. Fourier transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (29Si NMR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and energy-dispersive X-ray spectroscopy (EDS) data provided evidence for chemical attachment of organosilanes onto the carbon nanotube surface. UV−visible data also yielded evidence for selectivity and functionalization.