Browsing by Author "Kim, Myung Jong"

Now showing 1 - 7 of 7
  • Thumbnail Image
    Item
    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.
  • Thumbnail Image
    Item
    Carbon nanotube substrates and catalyzed hot stamp for polishing and patterning the substrates
    (2009-09-08) Wang, Yuhuang; Hauge, Robert H.; Schmidt, Howard K.; Kim, Myung Jong; Kittrell, Carter W.; Rice University; United States Patent and Trademark Office
    The present invention is generally directed to catalyzed hot stamp methods for polishing and/or patterning carbon nanotube-containing substrates. In some embodiments, the substrate, as a carbon nanotube fiber end, is brought into contact with a hot stamp (typically at 200-800° C.), and is kept in contact with the hot stamp until the morphology/patterns on the hot stamp have been transferred to the substrate. In some embodiments, the hot stamp is made of material comprising one or more transition metals (Fe, Ni, Co, Pt, Ag, Au, etc.), which can catalyze the etching reaction of carbon with H2, CO2, H2O, and/or O2. Such methods can (1) polish the carbon nanotube-containing substrate with a microscopically smooth finish, and/or (2) transfer pre-defined patterns from the hot stamp to the substrate. Such polished or patterned carbon nanotube substrates can find application as carbon nanotube electrodes, field emitters, and field emitter arrays for displays and electron sources.
  • Thumbnail Image
    Item
    Continued growth of single-walled carbon nanotubes from open-ended SWNT substrates
    (2006) Kim, Myung Jong; Hafner, Jason H.; Smalley, Richard E.
    We prepared nanoscopically flat open-ended SWNT substrates from SWNT spun fibers by using the microtome cutting technique or the focused ion beam cutting technique followed by various etching and cleaning schemes or alternatively from vertically aligned SWNT film by flipping-over. Deposited catalyst was docked to the open ends of SWNTs, and carbon feedstocks were catalyzed into continued single-walled carbon nanotube growth resembling 1D molecular epitaxy. The data obtained from Raman spectroscopy indicates that the (n, m) structure of the newly grown SWNT was cloned from that of the pre-existing SWNT substrate. Such results lead us to believe that this method will provide us with a means of chirality-controlled SWNTs growth on a macroscopic scale using a fairy general and scalable setup in the future.
  • Thumbnail Image
    Item
    Electrical device fabrication from nanotube formations
    (2013-03-12) Nicholas, Nolan Walker; Kittrell, Carter W.; Kim, Myung Jong; Schmidt, Howard K.; Rice University; United States Patent and Trademark Office
    A method for forming nanotube electrical devices, arrays of nanotube electrical devices, and device structures and arrays of device structures formed by the methods. Various methods of the present invention allow creation of semiconducting and/or conducting devices from readily grown SWNT carpets rather than requiring the preparation of a patterned growth channel and takes advantage of the self-controlling nature of these carpet heights to ensure a known and controlled channel length for reliable electronic properties as compared to the prior methods.
  • Thumbnail Image
    Item
    Embedded arrays of vertically aligned carbon nanotube carpets and methods for making them
    (2015-06-30) Kim, Myung Jong; Nicholas, Nolan Walker; Kittrell, Carter W.; Schmidt, Howard K.; Rice University; United States Patent and Trademark Office
    According to some embodiments, the present invention provides a system and method for supporting a carbon nanotube array that involve an entangled carbon nanotube mat integral with the array, where the mat is embedded in an embedding material. The embedding material may be depositable on a carbon nanotube. A depositable material may be metallic or nonmetallic. The embedding material may be an adhesive material. The adhesive material may optionally be mixed with a metal powder. The embedding material may be supported by a substrate or self-supportive. The embedding material may be conductive or nonconductive. The system and method provide superior mechanical and, when applicable, electrical, contact between the carbon nanotubes in the array and the embedding material. The optional use of a conductive material for the embedding material provides a mechanism useful for integration of carbon nanotube arrays into electronic devices.
  • Thumbnail Image
    Item
    Fibers comprised of epitaxially grown single-wall carbon nanotubes- and a method for added catalyst and continuous growth at the tip
    (2010-06-01) Kittrell, Carter W.; Wang, Yuhuang; Kim, Myung Jong; Hauge, Robert H.; Smalley, Richard E.; Marek, Irene Morin; Rice University; United States Patent and Trademark Office
    The present invention is directed to fibers of epitaxially grown single-wall carbon nanotubes (SWNTs) and methods of making same. Such methods generally comprise the steps of: (a) providing a spun SWNT fiber; (b) cutting the fiber substantially perpendicular to the fiber axis to yield a cut fiber; (c) etching the cut fiber at its end with a plasma to yield an etched cut fiber; (d) depositing metal catalyst on the etched cut fiber end to form a continuous SWNT fiber precursor; and (e) introducing feedstock gases under SWNT growth conditions to grow the continuous SWNT fiber precursor into a continuous SWNT fiber.
  • Thumbnail Image
    Item
    Recent advances and perspective on boron nitride nanotubes: From synthesis to applications
    (Springer Nature, 2022) Jakubinek, Michael B.; Kim, Keun Su; Kim, Myung Jong; Martí, Angel A.; Pasquali, Matteo; Bioengineering; Chemical and Biomolecular Engineering; Chemistry; Materials Science and Nanoengineering; Smalley-Curl Institute; Carbon Hub
    Boron nitride nanotubes (BNNTs) are emerging nanomaterials with analogous structures and similarly impressive mechanical properties to carbon nanotubes (CNTs), but unique chemistry and complimentary multifunctional properties, including higher thermal stability, electrical insulation, optical transparency, neutron absorption capability, and piezoelectricity. Over the past decade, advances in synthesis have made BNNTs more broadly accessible to the nanomaterials and other research communities, removing a major barrier to their utilization and research. Therefore, the field is poised to grow rapidly and see the emergence of BNNT applications ranging from electronics to aerospace materials. A key challenge, that is being gradually overcome, is the development of manufacturing processes to make “neat” BNNT materials. This overview highlights the history and current status of the field, providing both an introduction to this Focus Issue—BNNTs: Synthesis to Applications—as well as a perspective on advances, challenges, and opportunities for this emerging material.