Anisotropic carbon nanotube papers fabricated from multiwalled carbon nanotube webs

• Published in: Carbon (New York) Vol. 49; no. 7; pp. 2437 - 2443
• Main Authors: Inoue, Yoku, Suzuki, Yusuke, Minami, Yoshitaka, Muramatsu, Junichi, Shimamura, Yoshinobu, Suzuki, Katsunori, Ghemes, Adrian, Okada, Morihiro, Sakakibara, Shingo, Mimura, Hidenori, Naito, Kimiyoshi
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.06.2011; Elsevier
• Subjects: Alignment; Anisotropy; Carbon nanotubes; Cross-disciplinary physics: materials science; rheology; Electrical resistivity; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; Heat transfer; High speed; Materials science; Physics; Specific materials; Thermal conductivity; Webs; Design; Multiwalled nanotube; Anisotropy; Technology; High speed; Displacement rates; Carbon nanotubes; Thermal conductivity; Stacks; Forces; Binders; Structure
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2011.02.010

We fabricated large-scale anisotropic carbon nanotube (CNT) paper sheets by stacking long-lasting multiwalled CNT (MWCNT) webs without using binder materials. The MWCNTs are highly aligned in the webs and they retain their alignment in the fabricated paper. Although MWCNTs are just connected by van der Waals force, tensile strength is as strong as 75.6 MPa. In addition, resistivity and thermal conductivity is as good as 2.5 × 10 −3 Ω cm and 70 W/m K, respectively. The present high anisotropy ratios of 7.3 in resistivity and of 8.1 in thermal conductivity are due to the high alignment of the ultra-long MWCNTs which have lengths of millimeters. High-speed web drawing with a draw speed of over 10 m/s enables very rapid fabrication. The material properties of CNT structures can be measured by conventional methods for macroscopic samples rather than methods designed for nanomaterials. CNT web technology will enable CNTs to be used in new applications.