Ultrathin Transparent Conductive Films of Polymer-Modified Multiwalled Carbon Nanotubes
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- 作者：Vera Bocharova ; Anton Kiriy ; Ulrich Oertel ; Manfred Stamm ; Franç ; ois Stoffelbach ; Robert Jé ; rô ; me ; Christophe Detrembleur
- 刊名：Journal of Physical Chemistry B
- 出版年：2006
- 出版时间：August 3, 2006
- 年：2006
- 卷：110
- 期：30
- 页码：14640 - 14644
- 全文大小：261K
- 年卷期：v.110,no.30(August 3, 2006)
- ISSN：1520-5207
文摘
Deposition of multiwalled carbon nanotubes modified by poly(2-vinylpyridine) (CNT-g-P2VP) from aqueousdispersions at low pH is an effective method to prepare homogeneous ultrathin films with a tunable CNTsdensity. A percolation threshold of 0.25 
g/cm2 and a critical exponent 
= 1.24 have been found from dcconductivity measurements. The sheet resistance value agrees with the percolation theory for 2D films.According to AFM and electrical measurements, even when only 5% of the surface is covered by CNT-g-P2VPs, the sheet resistance is of the order of 1 M
/sq, which indicates that conductivity is imparted by anetwork of an ultralow density. When the film transmittance decreases down to ~70% at 550 nm, the occupiedsurface area is ~15% and sheet resistance falls down to ~90 k/sq. These data show that undesired in-planeclustering does not occur upon the dispersion casting of the films and that high-quality networks of CNT-g-P2VPs are built up. The electrosteric stabilization of the CNT-g-P2VP dispersions in water at low pH is atthe origin of this desired behavior. Although the multiwalled CNT films prepared in this work are lessconductive and less transparent than the SWNTs films, they could find applications, e.g., in touch screens,reflective displays, EMI shielding, and static charge dissipation.
g/cm2 and a critical exponent = 1.24 have been found from dcconductivity measurements. The sheet resistance value agrees with the percolation theory for 2D films.According to AFM and electrical measurements, even when only 5% of the surface is covered by CNT-g-P2VPs, the sheet resistance is of the order of 1 M/sq, which indicates that conductivity is imparted by anetwork of an ultralow density. When the film transmittance decreases down to ~70% at 550 nm, the occupiedsurface area is ~15% and sheet resistance falls down to ~90 k/sq. These data show that undesired in-planeclustering does not occur upon the dispersion casting of the films and that high-quality networks of CNT-g-P2VPs are built up. The electrosteric stabilization of the CNT-g-P2VP dispersions in water at low pH is atthe origin of this desired behavior. Although the multiwalled CNT films prepared in this work are lessconductive and less transparent than the SWNTs films, they could find applications, e.g., in touch screens,reflective displays, EMI shielding, and static charge dissipation.