• Title/Summary/Keyword: CNT spray

Search Result 49, Processing Time 0.025 seconds

Electrical Properties and Self-poling Mechanism of CNT/PVDF Piezoelectric Composite Films Prepared by Spray Coating Method

  • Lee, Sunwoo;Jung, Nak-Chun
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2013.08a
    • /
    • pp.256-256
    • /
    • 2013
  • Carbon nanotubes (CNT) / polyvinylidene fluoride (PVDF) piezoelectric composite films for nanogenerator devices were fabricated by spray coating method. When the CNT/PVDF mixture solution passes through the spray nozzle with small diameter by the compressed nitrogen gas, electric charges are generated in the liquid by a triboelectric effect. Then randomly distributed ${\beta}$ phase PVDF film could be re-oriented by the electric field resulting from the accumulated electrical charges, and might be resulted in extremely one-directionally aligned ${\beta}$ phase PVDF film without additional electric field for poling. X-ray diffraction patterns were used to investigate crystal structure of the CNT/PVDF composite films. It was confirmed that they revealed extremely large portion of the ${\beta}$ phase PVDF crystalline in the film. Therefore we could obtain the poled CNT/PVDF piezoelectric composite films by the spray coating method without additional poling process. Charge accumulation and resulting electric field generation mechanism by spray coating method were shown in Fig. 1. The capacitance of the CNT/PVDF films increased by adding CNTs into the PVDF matrix, and finally saturated. However, the I-V curves didn't show any saturation effect in the CNT concentration range of 0~4 wt%. Therefore we can control the performance of the devices fabricated from the CNT/PVDF composite film by adjusting the current level resulted from the CNT concentration with the uniform capacitance value.

  • PDF

Self-poling Mechanism of CNT/PVDF Piezoelectric Composite Films Prepared by Spray Coating Method (스프레이 코팅법으로 제조된 CNT/PVDF 압전 복합막의 자기분극 메커니즘)

  • Lee, Sunwoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.26 no.7
    • /
    • pp.550-554
    • /
    • 2013
  • Carbon nanotubes (CNT) / polyvinylidene fluoride (PVDF) piezoelectric composite films for nanogenerator devices were fabricated by spray coating method. When the CNT/PVDF mixture solution passes through the spray nozzle with small diameter by the compressed nitrogen gas, electric charges are generated in the liquid by a triboelectric effect. Then randomly distributed ${\beta}$ phase PVDF film could be re-oriented by the electric field resulting from the accumulated electrical charges, and might be resulted in extremely one-directionally aligned ${\beta}$ phase PVDF film without additional electric field for poling. X-ray diffraction patterns were used to investigate crystal structure of the CNT/PVDF composite films. It was confirmed that they revealed extremely large portion of the ${\beta}$ phase PVDF crystalline in the film. Therefore we could obtain the poled CNT/PVDF piezoelectric composite films by the spray coating method without additional poling process.

Flexible Antenna Radiator Fabricated Using the CNT/PVDF Composite Film (CNT/PVDF 복합막을 이용한 유연소자용 안테나 방사체)

  • Kim, YongJin;Lim, Young Taek;Lee, Sunwoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.28 no.3
    • /
    • pp.196-200
    • /
    • 2015
  • In this paper, we fabricated flexible antenna radiator using the CNT/PVDF (carbon nanotube / polyvinylidene fluoride) composite film. We used polymer film as a matrix material for the flexible devices, and introduced CNTs for adding conductivity into the film resulting in obtaining performances of the antenna radiator. Spray coating method was used to form the CNT/PVDF composite radiator, and pattern formation of the radiator was done by shadow mask during the spray coating process. We investigated the electrical properties of the CNT/PVDF composite films with the CNT concentration, and also estimated the radiator performance. Finally we discuss the feasibility of the CNT/PVDF composite radiator for the flexible antenna.

Effect of Transparency of CNT counter electrodes on the Efficiency of DSSCs

  • Lee, Won-Jae;Ramasamy, Easwaramoorthi;Lee, Dong-Yun;Song, Jae-Sung
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
    • /
    • 2005.07a
    • /
    • pp.615-616
    • /
    • 2005
  • Carbon Nanotubes (CNT) on flexible indium tin oxide (ITO) PET films were prepared for dye-sensitized solar cell (DSSC). These CNTs were prepared by spray coating method for various amount of light transparency. Also, Pt counter electrode was prepared by electro deposition method. All $TiO_2$ electrodes were deposited on ITO-PET films by spray coating method. Micro structural images show that CNT counter electrodes prepared by spray-coating have more dense structure with increasing spraying time (0 to 60 seconds). DSSC consisting of $TiO_2$ electrode and CNT counter electrode was fabricated with various amount of light absorption. DSSC have higher light energy conversion efficiency with increasing the thickness of CNT counter electrode. CNT counter electrode is at least compatible to that of CNT counter electrode.

  • PDF

Fabrication of CNT/PVDF Composite Film and Its Electrical Properties (CNT/PVDF 압전 복합막의 제작과 전기적 특성)

  • Lee, Sunwoo;Jung, Nak-Chun
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.26 no.8
    • /
    • pp.620-623
    • /
    • 2013
  • The carbon nanotube / poly-vinylidene fluoride (CNT/PVDF) composite films for the nano-generator devices were fabricated by spray coating method using the CNT/PVDF solution, which was prepared by adding PVDF pellets into the CNT dispersed N-Methyl-2-pyrroli-done (NMP) solution. The flexible CNT/PVDF composite films were investigated by the scanning electron microscopy, which revealed that the CNTs were uniformly dispersed in the PVDF matrix and thickness of the films was approximately $20{\mu}m$. Fourier transform infra-red spectra were used to investigate crystal structure of the as-spray-coated CNT/PVDF films, and we found that they revealed extremely large portion of the ${\beta}$ phase PVDF. The capacitance of the CNT/PVDF films increased by adding CNTs into the PVDF matrix, and finally saturated. However, the resistance didn't show any saturation effect in the CNT concentration range of 0~4 wt%. Finally, the resulting nano-generator devices revealed reasonable current output after given mechanical stress.

Spray-coated Carbon Nanotube Counter Electrodes for Dye-sensitized Solar Cells

  • Lee, Won-Jae;Lee, Dong-Yun;Kim, In-Sung;Jeong, Soon-Jong;Song, Jae-Sung
    • Transactions on Electrical and Electronic Materials
    • /
    • v.6 no.4
    • /
    • pp.140-143
    • /
    • 2005
  • Carbon Nanotube(CNTs) counter electrode is a promising alternative to Platinum counter electrode for dye sensitized solar cells (DSSCs). In this study, CNT counter electrodes having different visible light transmittance were prepared on fluorine-doped tin oxide (FTO) glass surface by spray coating method. Microstructural images show that there are CNT-tangled region coated on FTO glass counter electrodes. Using such CNT counter electrodes and screen printed $TiO_2$ electrodes, DSSCs were assembled and its I-V characteristics have been studied and compared. Light energy conversion efficiency of DSSCs increased with decreasing in light transmittance of CNT counter electrode. Efficiency of DSSCs having CNT counter electrode is compatible to that of Pt counter electrode.

Deposition Behavior and Properties of Carbon Nanotube Aluminum Composite Coatings in Kinetic Spraying Process (탄소 나노튜브 알루미늄 복합재료 저온 분사 코팅의 적층 거동 및 특성)

  • Kang, Ki-Cheol;Xiong, Yuming;Lee, Chang-Hee
    • Journal of Welding and Joining
    • /
    • v.26 no.5
    • /
    • pp.36-42
    • /
    • 2008
  • Carbon nanotube (CNT) aluminum composite coatings were built up through kinetic spraying process. Deposition behavior of CNT aluminum composite on an aluminum 1050 alloy substrate was analyzed based on deposition mechanism of kinetic spraying. The microstructure of CNT aluminum composite coating were observed and analyzed. Also, the electrical resistivity, bond strength and micro-hardness of the CNT aluminum composite coatings were measured and compared to kinetic sprayed aluminum coatings. The CNT aluminum composite coatings have a dense structure with low porosity. Compared to kinetic sprayed aluminum coating, the CNT aluminum composite coatings present lower electrical resistivity and higher micro-hardness due to high electrical conductivity and dispersion hardening effects of CNTs.

Relations Between Dispersion of CNTs and Electrical Conductivity in the Hydrophobic CNT/PVDF Composite Film (소수성 CNT/PVDF 복합막에서 CNT의 분산과 전도성의 관계)

  • Lee, Sunwoo
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
    • /
    • v.28 no.7
    • /
    • pp.462-466
    • /
    • 2015
  • In this paper, we investigated the relations between dispersion of CNTs (carbon nanotubes) and electrical conductivity in the CNT/PVDF (polyvinylidene fluoride) composite film. By adding hydrophobic CNTs as filler into the PVDF matrix, we fabricated hydrophobic and electrically conducting polymer coating film. Dispersion of CNTs in the CNT/PVDF composite film plays a significant role in terms of electrical conductivity and wetting property. Spray coating method was used to form the CNT/PVDF composite films by injecting the dispersed CNTs in the PVDF solution with different weight ratios from 0.7 wt% to 7 wt%. We investigated the electrical properties and contact angles of the CNT/PVDF composite films with the CNT concentration. Finally we discussed the conducting mechanism and feasibility of the CNT/PVDF composite film for the conducting polymer films.

Capacitance and Output Current Control by CNT Concentration in the CNT/PVDF Composite Films for Electronic Devices (전자소자로의 응용을 위한 CNT/PVDF 복합막에서 CNT 조성에 의한 정전용량과 출력전류 제어)

  • Lee, Sunwoo;No, Im-Jun;Shin, Paik-Kyun;Kim, Yongjin
    • The Transactions of The Korean Institute of Electrical Engineers
    • /
    • v.62 no.8
    • /
    • pp.1115-1119
    • /
    • 2013
  • The carbon nanotube/poly-vinylidene fluoride (CNT/PVDF) composite films for the use of electronic devices were fabricated by spray coating method using the CNT/PVDF solution, which was prepared by adding PVDF pellets into the CNT dispersed N-Methyl-2-pyrroli-done (NMP) solution. The CNT/PVDF composite films were peeled off from the glass substrate and were investigated by the scanning electron microscopy, which revealed that the CNTs were uniformly dispersed in the PVDF films and thickness of the films were approximately $20{\mu}m$. The capacitance of the CNT/PVDF films increased dramatically by adding CNTs into the PVDF matrix, and finally saturated approximately 1880 pF. However, the I-V curves didn't show any saturation effect in the CNT concentration range of 0 ~ 0.04 wt%. Therefore we can control the performance of the devices from the CNT/PVDF composite film by adjusting the current level resulted from the CNT concentration with the uniform capacitance value.

MWCNT thin film based supercapictor using spray deposition and gel electrolytes

  • Han, Song-Yi;Park, Sung-Hwak;Kim, Sung-Hyun;Kim, Sun-Min;Han, Joung-Hoon;Bae, Joon-Ho;Lee, Churl-Seung
    • Proceedings of the Korean Vacuum Society Conference
    • /
    • 2011.02a
    • /
    • pp.465-465
    • /
    • 2011
  • In recent years, electrochemical supercapacitors have attracted much attention due to their high power density, long life cycles, and high efficiency. Some supercapacitors using CNTs have been reported, but there are several issues to be resolved for further development of CNT based supercapacitors. One issue is time consuming procedures to prepare CNT films, which may provide poor control of CNT uniformity over the large area of the substrates. Another is new electrolytes replacing the conventional liquid electrolytes in supercapacitors. In this work, We have successfully demonstrated that spray deposition method of multiwalled CNT films using gel electroytes could be promising for CNT-based supercapacitors on ITO substrates. Specific capacitances using gel electrolyte reached up to 1.5 F/g and 9 mF/$cm^2$, and internal resistance was 28 ${\Omega}$. Specific capacitances and internal resistance of supercapacitors with gel electrolyte were better than or comparable to those with liquid electrolytes($KNO_3$, $Na_2SO_4$), indicating that gel electrolytes could replace liquid counterparts in CNT-based supercapacitors. Combined with gel electrolyte, spray deposition method could provide low cost and easily scalable process for high performance supercapacitors using CNT films on ITO for applications in display devices.

  • PDF