Reductive alkylation of single-walled carbon nanotubes (SWNTs) using lithium and alkyl halides in liquid ammonia yields sidewall functionalized nanotubes that are soluble in common organic solvents. Atomic force microscopy (AFM) and high-resolution tunneling electron microscopy (HRTEM) of dodecylated SWNTs prepared from raw HiPco nanotubes show that extensive debundling has occurred. GC-MS analysis of the byproduct hydrocarbons demonstrates that alkyl radicals are intermediates in the alkylation step.

The oxidation reaction of piranha solutions with purified HiPco carbon nanotubes was measured as a function of temperature. At high temperatures, piranha is capable of attacking existing damage sites, generating vacancies in the graphene sidewall, and consuming the oxidized vacancies to yield short, cut nanotubes. Increased reaction time results in increasingly shorter nanotubes. However, significant sidewall damage occurs as well as selective etching of the smaller diameter nanotubes. On the other hand, room-temperature piranha treatments show the capability of cutting existing damage sites with minimal carbon loss, slow etch rates, and little sidewall damage. Combined with a method of introducing controlled amounts of damage sites, these room-temperature piranha solutions have the potential to yield an efficient means of creating short, cut nanotubes.

The reaction of nanoscale diamond (ND) powder with an elemental fluorine/hydrogen mixture at temperatures varying from 150 to 470 °C resulted in the high degree of ND surface fluorination yielding a fluoro-nanodiamond with up to 8.6 at. % fluorine content. The fluoronanodiamond was used as a precursor for preparation of the series of functionalized nanodiamonds by subsequent reactions with alkyllithium reagents, diamines, and amino acids. The fluoro-nanodiamond and corresponding alkyl-, amino-, and amino acid-nanodiamond derivatives were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), Fourier transformed infrared (FTIR) and X-ray photoelectron spectroscopy (XPS), and thermal gravimetry-mass spectrometry (TG-MS) measurements. In comparison with the pristine nanodiamond, all functionalized nanodiamonds show an improved solubility in polar organic solvents, e.g., alcohols and THF, and a reduced particle agglomeration. The developed methodology provides an efficient method for the chemical modification of nanodiamond powder, which enables a variety of engineering and biomedical applications of ND derivatives.