• Title/Summary/Keyword: Carbon nanotube (CNT)

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Synthesis and Li Electroactivity of MnS/Carbon Nanotube Composites (MnS / 카본나노튜브 복합체의 합성과 리튬 전기화학적 거동)

  • Lee, Gwang-Hee;Min, Kyung-Mi;Kim, Dong-Wan
    • Journal of the Korean Ceramic Society
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    • v.50 no.6
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    • pp.539-544
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    • 2013
  • A simple synthetic process is demonstrated for the preparation of MnS/carbon nanotube (CNT) composites for Li ion battery electrodes. CNTs were initially treated using a strong acid solution to generate carboxylate ions ($-COO^-$) on their surfaces. The MnS/CNT composites were synthesized by a polyvinyl-pyrrolidone-assisted hydrothermal method in the presence of as-functionalized CNTs. The phase and morphology of the MnS/CNT composites and pure MnS microspheres were characterized using X-ray diffraction and high-resolution transmission electron microscopy. Furthermore, the Li electroactivity levels of the MnS/CNT composites and MnS microspheres were investigated using cyclic voltammetry and galvanostatic cycling. The MnS/CNT composite electrodes showed higher specific capacities exceeding 365 $mA\;h\;g^{-1}$ at a C/10 current rate and enhanced cyclic performance compared to pure MnS microspheres.

An Integrated Approach of CNT Front-end Amplifier towards Spikes Monitoring for Neuro-prosthetic Diagnosis

  • Kumar, Sandeep;Kim, Byeong-Soo;Song, Hanjung
    • BioChip Journal
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    • v.12 no.4
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    • pp.332-339
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    • 2018
  • The future neuro-prosthetic devices would be required spikes data monitoring through sub-nanoscale transistors that enables to neuroscientists and clinicals for scalable, wireless and implantable applications. This research investigates the spikes monitoring through integrated CNT front-end amplifier for neuro-prosthetic diagnosis. The proposed carbon nanotube-based architecture consists of front-end amplifier (FEA), integrate fire neuron and pseudo resistor technique that observed high electrical performance through neural activity. A pseudo resistor technique ensures large input impedance for integrated FEA by compensating the input leakage current. While carbon nanotube based FEA provides low-voltage operation with directly impacts on the power consumption and also give detector size that demonstrates fidelity of the neural signals. The observed neural activity shows amplitude of spiking in terms of action potential up to $80{\mu}V$ while local field potentials up to 40 mV by using proposed architecture. This fully integrated architecture is implemented in Analog cadence virtuoso using design kit of CNT process. The fabricated chip consumes less power consumption of $2{\mu}W$ under the supply voltage of 0.7 V. The experimental and simulated results of the integrated FEA achieves $60G{\Omega}$ of input impedance and input referred noise of $8.5nv/{\sqrt{Hz}}$ over the wide bandwidth. Moreover, measured gain of the amplifier achieves 75 dB midband from range of 1 KHz to 35 KHz. The proposed research provides refreshing neural recording data through nanotube integrated circuit and which could be beneficial for the next generation neuroscientists.

Manipulation of Carbon Nanotube Tip Using Focused Ion Beam (집속이온빔을 이용한 탄소나노튜브 팁의 조작)

  • Yoon, Yeo-Hwan;Park, June-Ki;Han, Chang-Soo
    • Journal of the Korean Society for Precision Engineering
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    • v.23 no.12 s.189
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    • pp.122-127
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    • 2006
  • This paper reports on the development of carbon nanotube tip modified with focused ion beam(FIB). We used an electric field which causes dielectrophoresis, to align and deposit CNTs on a metal-coated canning Probe Microscope (SPM) tip. Using the CNT attached SPM tip, we have obtained an enhanced resolution and wear property compared to that from the bare silicon tip through the scanning of the surface of the bio materials. The carbon nanotube tip was aligned toward the source of the ion beam allowing their orientation to be changed at precise angles. By this technique, metal coated carbon nanotube tips that are several micrometer in length are prepared for SPM.

Actively Addressable Carbon NanoTube Emitters for Field Emission Display

  • Song, Yoon-Ho;Hwang, Chi-Sun;Kim, Kwang-Bok
    • 한국정보디스플레이학회:학술대회논문집
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    • 2003.07a
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    • pp.194-197
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    • 2003
  • The actively addressable carbon nanotube (CNT) emitters have been studied for stable and low-voltage driving field emission display (FED). The a-Si TFT and screen-printed CNT emitters were successfully integrated to fabricate the diode type active-matrix cathode and FED panel. Also, we propose a new FED architecture based on the actively controlled triode CNT emitters showing the properties of ideal triode type cathode with electron beam focusing effect.

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Removal Characteristics of Cu(II) by PSf/D2EHPA/CNT Beads Prepared by Immobilization of Carbon Nanotubes (CNT) and Di-(2-ethylhexyl)-phosphoric acid (D2EHPA) on Polysulfone (PSf) (Polysulfone으로 carbon nanotubes (CNT)와 di-(2-ethylhexyl)-phosphoric acid (D2EHPA)를 고정화한 PSf/D2EHPA/CNT 비드에 의한 Cu(II)의 제거특성)

  • Lee, Chang-Han;Lee, Min-Gyu
    • Journal of Environmental Science International
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    • v.25 no.11
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    • pp.1485-1491
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    • 2016
  • PSf/D2EHPA/CNT beads were prepared by immobilizing di-(2-ethylhexyl)-phosphoric acid (D2EHPA) and carbon nanotubes (CNT) on polysulfone (PSf) and used to remove Cu(II) from aqueous solutions. Optimum pH was in the range of 4 to 6. The removal kinetic of Cu(II) by the prepared PSf/D2EHPA/CNT beads was mainly governed by internal diffusion, and the diffusion coefficient of Cu(II) by PSf/D2EHPA/CNT beads was found to be $2.19{\times}10^{-4}{\sim}2.64{\times}10^{-4}cm^2/s$. The Langmuir isotherm model predicted the experimented data well. The maximum removal capacity of Cu(II) obtained from this isotherm was 7.32 mg/g. Calculated thermodynamic parameters such as ${\Delta}G^o$, ${\Delta}H^o$ and ${\Delta}S^o$ showed that the adsorption of Cu(II) ions onto PSf/D2EHPA/CNT beads was feasible, spontaneous and endothermic at 293-323 K.

In-situ TEM of Carbon Nanotube Field Emitters and Improvement of Electron Emission from Nanotube Films by Laser Treatment

  • Saito, Yahachi;Seko, Kazuyuki;Kinoshita, Jun-ichi;Ishida, Toshiyuki;Yotani, Junko;Kurachi, Hiroyuki;Uemura, Sashiro
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07b
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    • pp.1081-1086
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    • 2005
  • Dynamic behavior of carbon nanotubes (CNTs) in an electric field is directly observed by in-situ transmission electron microscopy (TEM). The CNT field emitters examined by in-situ TEM are multiwalled, double-walled and single walled CNTs. Threshold fields for electron emission and sustainable emission currents depending on the structure of CNTs are presented, and degradation mechanism of the CNT field emitters is discussed. In addition to the microscopy studies on individual CNTs, our recent development in surface treatment of CNT layers grown by chemical vapor deposition, which brings about high density of emission current and high uniformity, is also presented.

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Fabrication of the CNT-FET biosensors with a double-gate structure (더블 게이트 구조의 탄소 나노 튜브 트랜지스터 바이오 센서의 제작)

  • Cho, Byung-Hyun;Lim, Byoung-Hyun;Shin, Jang-Kyoo;Choi, Sung-Wook;Chun, Hyang-Sook
    • Journal of Sensor Science and Technology
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    • v.18 no.2
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    • pp.168-172
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    • 2009
  • In this paper, we present the carbon nanotube field-effect transistor(CNT-FET) with a double-gate structure. A Carbon nanotube film was aligned by the Langmuir-Blodgett technique and $SiN_x$ was deposited to protect from water, oxygen, and other contaminants. We measured the electrical characteristics of the proposed device as the function of the $V_{BG}$, $V_{TG}$. From this result, we can confirm that proposed device might be employed as a biosensor.

Cost effective CNT-BLU

  • Han, In-Taek;Kim, Yong-Cheol;Kim, Ha-Jin;Kim, Young-Whan;Kim, Jong-Min
    • 한국정보디스플레이학회:학술대회논문집
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    • 2009.10a
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    • pp.145-147
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    • 2009
  • The cost effective structures and materials for the carbon nanotube (CNT) back light unit (BLU) are proposed. Simplified device structures and related electron emitter materials are prepared. CNT emitters were screen printed or remotely mounted on the back plate, and this enabled less than two photo patterning steps. Besides the cost benefits, operating voltage was dramatically decreased and higher current density was obtained

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Permittivity of Semiconductive Shield Materials in Power Cables by Frequency, Temperature (주파수, 온도에 따른 전력케이블용 반도전 재료의 유전올)

  • Yang, Hoon;Park, Dae-Hee
    • Proceedings of the KIEE Conference
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    • 2007.11a
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    • pp.218-219
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    • 2007
  • This paper researched permittivity of carbon nanotube reinforced semiconductive shield materials for power cable in accordance with carbon nanotube content. Permittivity measured 1[Hz], 1[kHz], 1[Mhz] in frequency range, and range of temperature measured to 100$[^{\circ}C]$ from -50$[^{\circ}C]$. It is stable to 100$[^{\circ}C]$ from -50$[^{\circ}C]$ without different gap. But, in case of CNT:CB=100:0, permittivity decreased by temperature increment. Also, in case of CNT:CB=100:0, it shows highest permittivity. Permittivity of change have little no the power of influence by frequency, but in case of 1[Mhz], CNT:CB=100:0 of specimen decreased more than other frequency. This influence thinks phenomenon of induced electricity dispersion.

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Improvement of thermal buckling response of FG-CNT reinforced composite beams with temperature-dependent material properties resting on elastic foundations

  • Bensaid, Ismail;Kerboua, Bachir
    • Advances in aircraft and spacecraft science
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    • v.6 no.3
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    • pp.207-223
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    • 2019
  • Current investigation deals with the thermal stability characteristics of carbon nanotube reinforced composite beams (CNTRC) on elastic foundation and subjected to external uniform temperature rise loading. The single-walled carbon nanotubes (SWCNTs) are supposed to have a distribution as being uniform or functionally graded form. The material properties of the matrix as well as reinforcements are presumed to be temperature dependent and evaluated through the extended rule of mixture which incorporates efficiency parameters to capture the size dependency of the nanocomposite properties. The governing differential equations are achieved based on the minimum total potential energy principle and Euler-Bernoulli beam model. The obtained results are checked with the available data in the literature. Numerical results are supplied to examine the effects of numerous parameters including length to thickness ratio, elastic foundations, temperature change, and nanotube volume fraction on the thermal stability behaviors of FG-CNT beams.