Browsing by Author "Shan, Hongwei"

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    Carbon nanotube diameter selection by pretreatment of metal catalysts on surfaces
    (2012-02-28) Hauge, Robert H.; Xu, Ya-Qiong; Shan, Hongwei; Nicholas, Nolan Walker; Kim, Myung Jong; Schmidt, Howard K.; Kittrell, Carter W.; Rice University; United States Patent and Trademark Office
    A new and useful nanotube growth substrate conditioning processes is herein disclosed that allows the growth of vertical arrays of carbon nanotubes where the average diameter of the nanotubes can be selected and/or controlled as compared to the prior art.
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    Purification of carbon nanotubes based on the chemistry of fenton's reagent
    (2009-02-24) Marek, Irene Morin; Wang, Yuhuang; Hauge, Robert H.; Shan, Hongwei; Rice University; United States Patent and Trademark Office
    The present invention is directed to methods of purifying carbon nanotubes (CNTs). In general, such methods comprise the following steps: (a) preparing an aqueous slurry of impure CNT material; (b) establishing a source of Fe2+ ions in the slurry to provide a catalytic slurry; (c) adding hydrogen peroxide to the catalytic slurry to provide an oxidative slurry, wherein the Fe2+ ions catalyze the production of hydroxyl radicals; and (d) utilizing the hydroxyl radicals in the oxidative slurry to purify the CNT material and provide purified CNTs.