[신간의 별자리x] 우리/미술, 그리고 ‘슬픔의 박물관’

Graphene, or single-layered graphite, with its high crystallinity and interesting semimetal electronic properties, has emerged as an exciting two-dimensional material showing great promise for the fabrication of nanoscale devices. Thin, elongated strips of graphene that possess straight edges, termed graphene ribbons, gradually transform from semiconductors to semimetals as their width increases, and represent a particularly versatile variety of graphene. Several lithographic, chemical and synthetic procedures are known to produce microscopic samples of graphene nanoribbons, and one chemical vapour deposition process has successfully produced macroscopic quantities of nanoribbons at 950 degrees C. Here we describe a simple solution-based oxidative process for producing a nearly 100% yield of nanoribbon structures by lengthwise cutting and unravelling of multiwalled carbon nanotube (MWCNT) side walls. Although oxidative shortening of MWCNTs has previously been achieved, lengthwise cutting is hitherto unreported. Ribbon structures with high water solubility are obtained. Subsequent chemical reduction of the nanoribbons from MWCNTs results in restoration of electrical conductivity. These early results affording nanoribbons could eventually lead to applications in fields of electronics and composite materials where bulk quantities of nanoribbons are required.

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Longitudinal unzipping of carbon nanotubes to form graphene nanoribbons

Graphene, a two-dimensional, single-layer sheet of sp(2) hybridized carbon atoms, has attracted tremendous attention and research interest, owing to its exceptional physical properties, such as high electronic conductivity, good thermal stability, and excellent mechanical strength. Other forms of graphene-related materials, including graphene oxide, reduced graphene oxide, and exfoliated graphite, have been reliably produced in large scale. The promising properties together with the ease of processibility and functionalization make graphene-based materials ideal candidates for incorporation into a variety of functional materials. Importantly, graphene and its derivatives have been explored in a wide range of applications, such as electronic and photonic devices, clean energy, and sensors. In this review, after a general introduction to graphene and its derivatives, the synthesis, characterization, properties, and applications of graphene-based materials are discussed.

Graphene-Based Materials: Synthesis, Characterization, Properties, and Applications

Skin plays an important role in mediating our interactions with the world. Recreating the properties of skin using electronic devices could have profound implications for prosthetics and medicine. The pursuit of artificial skin has inspired innovations in materials to imitate skin's unique characteristics, including mechanical durability and stretchability, biodegradability, and the ability to measure a diversity of complex sensations over large areas. New materials and fabrication strategies are being developed to make mechanically compliant and multifunctional skin-like electronics, and improve brain/machine interfaces that enable transmission of the skin's signals into the body. This Review will cover materials and devices designed for mimicking the skin's ability to sense and generate biomimetic signals.

Pursuing prosthetic electronic skin.

We have developed a method to separate metallic from semiconducting single-walled carbon nanotubes from suspension using alternating current dielectrophoresis. Our method takes advantage of the difference of the relative dielectric constants of the two species with respect to the solvent, resulting in an opposite movement of metallic and semiconducting tubes along the electric field gradient. Metallic tubes are attracted toward a microelectrode array, leaving semiconducting tubes in the solvent. Proof of the effectiveness of separation is given by a comparative Raman spectroscopy study on the dielectrophoretically deposited tubes and on a reference sample.

https://science.sciencemag.org/content/sci/301/5631/344.full.pdf

Separation of Metallic from Semiconducting Single-Walled Carbon Nanotubes

Conductive niobium carbide (NbC) nanowires with diameters of 1–3 nm were synthesized within the inner space of carbon nanotubes (CNTs) by exposing the CNTs to niobium (V) chloride vapor through hydrogen reduction. The NbC nanowires were found to have a NaCl-type crystal structure by transmission electron microscopy and transmission electron diffractometry. Results from electronic transport measurements imply that the electrical conductivity of the synthesized product was improved compared with that of empty CNTs.

https://iopscience.iop.org/article/10.7567/APEX.7.015101/pdf

Synthesis of refractory conductive niobium carbide nanowires within the inner space of carbon nanotube templates

/pdf/magnetic-susceptibility-of-the-one-dimensional-polymeric-4hzcta0zmh.pdf

Magnetic susceptibility of the one-dimensional polymeric phase of RbC60

PROBLEM TO BE SOLVED: To provide a synthesis method of a carbon nanotube (CNT) assembly which contains a single walled carbon nanotube (SWCNT) and a double walled carbon nanotube (DWCNT), in which each of the SWCNT and the DWCNT has a small diameter, and, based on this fact, with which a transparent conductive film having excellent electric conductivity can be formedSOLUTION: A synthesis method of a CNT assembly of this invention is a synthesis method of CNTs to synthesize the CNTs in a fluidizing vapor phase by introducing a catalyst metal and/or a precursor thereof, a carbon source, and a carrier gas into a furnace The carbon source contains a first carbon source being an organic compound which is a liquid in atmospheric temperature and in atmospheric pressure, a second carbon source being methane, and a third carbon source selected from a group consisting of ethane, ethylene, acetylene, propane, propylene, propyne, and a combination thereof The carrier gas is a mixed gas of hydrogen and an inert gas

Carbon nanotube assembly containing single walled carbon nanotube and double walled carbon nanotube, and synthesis method thereof

産業技術総合研究所の有機化合物スペクトルデータベース（SDBS）は1982年に開発を開始し、以来30年間変わらない部分と大きな変化を遂げた部分を混在させつつ高度化されてきた。標準スペクトルとして信頼性の高いものを収録すること、1種類の化合物に複数種類のスペクトルを収録することの二つの基本コンセプトと、汎用化合物を対象とする点は、開発当初から現在まで変わらず引き継がれている。一方、データベースを収集するプラットフォームと公開形式は大きく変わった。データのウェブ公開に伴ってユーザーからの声を取り上げ、各種の依頼や指摘に対応するようになったことも、大きく変わった点である。長期間にわたって開発と公開サービスを継続し、現在ウェブを通して多くの研究者、技術者、教育者、学生らによって利用されるにいたった。データベースの全体構想から、構造の設定、データの収集方法、データの公開方法等主要なプロセスを統合的、構成的に記述する。

Development and release of a spectral database for organic compounds

Transparent conductive thin films of single-wall carbon nanotubes (SWCNTs) doped with organic dopant molecules encapsulated inside the SWCNTs are reported. Doping with tetrafluorotetracyano-p-quinodimethane encapsulated within the SWCNTs improved the ratio of direct current to optical conductivity in the SWCNT thin films by a factor of about 1.8. Thermal stability of the improvement in electrical conductivity by encapsulation doping is investigated as a function of annealing temperature. We found that encapsulation doping provides stable conductivity enhancement in transparent thin films of SWCNTs compared to doping by adsorbed dopant molecules outside the SWCNTs.

Takeshi Saito

Papers

Synthesis of refractory conductive niobium carbide nanowires within the inner space of carbon nanotube templates

Magnetic susceptibility of the one-dimensional polymeric phase of RbC60

Carbon nanotube assembly containing single walled carbon nanotube and double walled carbon nanotube, and synthesis method thereof

Development and release of a spectral database for organic compounds

Transparent conductive thin films of single-wall carbon nanotubes encapsulating dopant molecules