• Composites Research
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• 제29권4호
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• pp.161-166
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• 2016

본 연구에서는 습식초지법을 이용하여 탄소나노튜브 버키페이퍼를 제조하고 고강도, 고강성 그리고 유연성을 증대시키기 위하여 폴리우레탄(PU)의 점도를 조절하여 코팅제조한 후 기계적 특성에 미치는 영향에 대하여 살펴보았다. Raman, TGA, PL, SEM, TEM 그리고 Tensile test을 이용하여 SWNTs, SWNTs-buckypaper(SWNTs-BP), 그리고 SWNTs-BP/PU 나노복합필름에 대한 구조 및 물성을 평가하였으며 복합필름단면은 전계방사 주사전자현미경(FE-SEM)을 사용하여 관찰한 후 물성증대원인을 해석하였다. 특히, 5 wt%의 PU 용액으로 코팅할 때 튜브간의 계면 접착력 증가로 최종 물성향상에 기여하였다. 최종적으로 이러한 구조적인 특성을 이용할 경우 초경량, 고강도 나노복합소재를 제조하는데 기여할 것으로 기대된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2004년도 추계학술대회 논문집
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• pp.881-885
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• 2004

We report a method for making a device on which semi-conducting single-walled carbon nanotubes are attached selectively between two metal electrodes. This method is divided two processes. First we can connect a rope of single-walled carbon nanotubes(SWNTs) between two electrodes using the electric field. But a SWNTs' rope obtained by the first process was composed of a few of metallic and semi-conducting SWNTs together. The second process is to burn the metallic and semi-conducting nanotubes through applying a voltage. As a result, we can obtain a semi-conducting SWNT device. To make the patterned electrodes, we deposited $SiO_2$(150nm) on a wafer. After then, we made a patterned samples with Ti(200 $\AA$)/Au(300$\AA$). We empirically obtained a electric condition 0.66 $V_{pp}$ /${\mu}{\textrm}{m}$@5MHz. From this result, we verified that most of current go through the metallic nanotubes in this device. When we apply DC voltage between two electrodes, the metallic carbon nanotubes are burnt. Finally, we can obtain a semi-conducting nanotube device which we desire to make. We got the I-V characteristic graph which has shown the semi-conducting property. We hope to apply to the various applications using this selective semi-conducting carbon nanotube deposition method.ethod.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2363-2368
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• 2007

A glassy carbon electrode (GCE) modified with phytic acid (PA) and single-walled carbon nanotubes (SWNTs) were investigated by voltammetric methods in buffer solution. The PA-SWNTs/GCE-modified electrode demonstrated substantial enhancements in electrochemical sensitivity and selectivity towards dopamine (DA) in the presence of L-ascorbic acid (AA). The PA-SWNTs films promoted the electron transfer reaction of DA, while the PA film, acting as a negatively charged linker, combined with the positively charged DA to induced DA accumulation in the film at pH under 7.4. However, the PA film restrained the electrochemical response of the negatively charged AA due to the electrostatic repulsion. The anodic peak potentials of DA and AA could be separated by electrochemical techniques, and the interferences from AA were effectively eliminated in the DA determination. Linear calibration plots were obtained in the DA concentration range of 0.1-10 μM and the detection limit of the DA oxidation current was determined to be 0.06 μM at a signal-to-noise ratio of 3. The results indicated that the modified electrode is used to determine DA without interference from AA.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2018년도 춘계학술대회 논문집
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• pp.47-47
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• 2018

단일벽 탄소나노튜브 (Single-walled carbon nanotubes, SWNTs)는 우수한 물리적 화학적 특성을 갖고 있어 나노전자소자, 투명전도막, 에너지소자, 센서 등 다양한 분야로의 응용이 기대되고 있다. 열화학기상증착(Thermal chemical vapor deposition, TCVD)법은 SWNTs의 합성 공정이 간단하고 공정변수의 제어가 용이하다는 장점이 있어 SWNT 합성 연구에 가장 널리 사용되어 왔다. 일반적으로 금속 촉매의 박막이 증착된 합성 기판은 온도가 가장 높고 비교적 균일성이 보장되는 TCVD 반응기의 중심부에 위치시키고 공정변수를 변화해가며 연구를 진행해 왔다. 본 실험실에서는 수평형 반응기 전역에 합성 기판을 설치하여 SWNTs를 합성한 결과, 반응기의 중심보다 뒤의 영역에서 SWNTs의 합성 수율이 상당히 증가하는 것을 초기실험을 통해 확인하였다. 본 연구에서는 SWNTs 합성 시 가스 유량과 합성 온도를 변화시켰을 때 기판 위치에 따른 SWNTs의 수율 및 물성변화를 구체적으로 조사하였다. 합성가스와 촉매로는 메탄가스와 철 박막을 사용하였으며, 합성 수율의 변화는 고분해능 주사전자현미경을 이용하여 관찰하였다. 그리고 합성된 SWNTs의 형태 및 결정성은 라만분광법과 원자간힘현미경을 이용하여 평가하였다. 결과적으로, 진행하였던 모든 합성 조건에서 반응기 중심보다 뒤의 영역에서 더 고수율의 SWNTs가 합성되었으며, 최적 합성 조건의 SWNTs 면밀도는 99% 이상이었다. 본 연구의 결과는 CVD 공정을 이용하는 다양한 저차원 나노 소재의 합성에도 적용될 수 있을 것으로 사료되며, 추후 이에 대한 연구가 필요하다.

• 한국표면공학회지
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• 제52권6호
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• pp.357-363
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• 2019

We investigated a synthesis yield and diameter distribution of single-walled carbon nanotubes (SWNTs) with respect to the growth position in a horizontal chemical vapor deposition (CVD) chamber. Thin films and line-patterned Fe films (0.1 nm thickness) were prepared onto ST-cut quartz substrates as catalyst to compare the growth behavior. The line-patterned samples showed higher growth density and parallel alignment than those of the thin film catalyst samples. In addition, line density of the aligned SWNTs at central region of the chamber was 7.7 tubes/㎛ and increased to 13.9 tubes/㎛ at rear region of the CVD chamber. We expect that the enhanced amount of thermally decomposed feedstock gas may contribute to the growth yield enhancement at the rear region. In addition, the lamina flow in the chamber also contribute to the perfect alignment of the SWNTs based on the value of gas velocity, Reynold number, and Knudsen coefficient we employed.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.700-702
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• 2004

The dependence of environmental gases such as Ar, $O_2$ on the emission current from carbon nanotube emitters was examined in this study. Based on our experiments, the current density is decreased in single-wall carbon nanotubes (SWNTs), but is increased in multi-wall carbon nanotubes (MWNTs) as the vacuum level decreases from $10^{-7}$ Torr to $10^{-4}$ Torr by the inflow purging gases. The current density subsequently recovered as the vacuum level increased to $10^{-7}$ Torr when gas inflow stopped. From those results, we conclude that the MWNTs have completely different degradation characteristics in comparison to SWNTs excluding the effect of binder materials.

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2004년도 Asia Display / IMID 04
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• pp.465-467
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• 2004

We presented a systematic investigation on the growth of CNTs including SWNTs on nano-catalyst-embedded particles by PECVD. For CNTs growth, the mixture of $C_2H_2$ and $NH_3$ was used. The total pressure and temperature were kept at 3.25 Torr and 650 $^{\circ}C$, respectively. Finally, we measured the field emission property from CNTs grown from nano-catalyst embedded zeolite particles in vacuum chamber (<$10^{-7}$ Torr).

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2007년도 7th International Meeting on Information Display 제7권2호
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• pp.1625-1628
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• 2007

Dispersion of arc-discharged single-walled carbon nanotubes (SWNTs) has been accomplished by a water soluble polymer wrapping functionalization at room temperature. The treated SWNTs were redispersed in both aqueous and many organic solvents and the solutions were found to be stable.

• 한국재료학회:학술대회논문집
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• 한국재료학회 2011년도 춘계학술발표대회
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• pp.25.2-25.2
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• 2011

The tungsten oxide wire-like nanostructure is fabricated by deposition and thermal oxidation of tungsten metal on porous single wall carbon nanotubes (SWNTs). The morphology and crystalline quality of materials are investigated by SEM, TEM, XRD and Raman analysis. The results prove that $WO_3$ wire-like nanostructure fabricated on SWNTs show highly porous structures. Exposure of the sensors to NH3 gas in the temperature range of 150~300$^{\circ}C$ resulted in the highest sensitivity at $250^{\circ}C$ with quite rapid response and recovery time. Response time as a function of test concentrations and NH3 gas sensing mechanism is reported and discussed.

• Carbon letters
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• 제20권
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• pp.26-31
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• 2016

In this study, we report a general method for preparation of a one-dimensional (1D) arrangement of Au nanoparticles on single-walled carbon nanotubes (SWNTs) using biologically programmed peptides as structure-guiding 1D templates. The peptides were designed by the combination of glutamic acid (E), glycine (G), and phenylalanine (F) amino acids; peptides efficiently debundled and exfoliated the SWNTs for stability of the dispersion and guided the growth of the array of Au nanoparticles in a controllable manner. Moreover, we demonstrated the superior ability of 1D nanohybrids as flexible, transparent, and conducting materials. The highly stable dispersion of 1D nanohybrids in aqueous solution enabled the fabrication of flexible, transparent, and conductive nanohybrid films using vacuum filtration, resulting in good optical and electrical properties.