Multiwalled carbon nanotube monoliths prepared by spark plasma sintering (SPS) and their mechanical properties

Issue title: Selected papers presented at the International Symposium on Nanotoxicity Assessment and Biomedical Environmental Application of Fine Particles and Nanotubes, Hokkaido, Japan, 16–17 June 2008, Part 1

Article type: Research Article

Authors: Uo, Motohiro^; | Hasegawa, Tomoka | Akasaka, Tsukasa | Tanaka, Isao | Munekane, Fuminori | Omori, Mamoru | Kimura, Hisamichi | Nakatomi, Reiko | Soga, Kohei | Kogo, Yasuo | Watari, Fumio

Affiliations: Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Sapporo, Japan | Shimizu Corporation, Tokyo, Japan | Nano Carbon Technologies Co., Ltd., Tokyo, Japan | Institute of Materials Research, Tohoku University, Sendai, Japan | Department of Materials Science and Technology, Faculty of Industrial Science and Technology, Tokyo University of Science, Tokyo, Japan

Note: [] Address for correspondence: Motohiro Uo, Department of Biomedical Materials and Engineering, Graduate School of Dental Medicine, Hokkaido University, Kita 13, Nishi 7, Kita-ku, Sapporo 060-8586, Japan. Tel./Fax: +81 11 706 4250; E-mail: [email protected].

Abstract: Three types of multiwalled carbon nanotube (MWCNT) monoliths without any binders were obtained by spark plasma sintering (SPS) treatment at 2000°C under 80 MPa sintering pressure. Three MWCNTs with different diameters: thin (∅20–30 nm, CNT Co., Ltd., Korea), thick (∅100 nm, Nano Carbon Technologies Co., Ltd., Japan) and spherical thin (∅20–30 nm, granulated diameter = 1–3 μm, Shimizu Corporation, Japan) were employed for SPS. SEM observation confirmed that these materials maintained the nanosized tube microstructure of raw CNT powder after SPS treatment. The densest monolith was prepared with the spherical MWCNTs. The mechanical properties of this material were estimated by the dynamic hardness test. The elastic modulus of the monolith did not depend on the difference of MWCNTs, but the hardness of spherical MWCNTs was higher than that of thick MWCNTs. The high density and hardness of the spherical MWCNTs were caused by the high packing density during the SPS process because of its spherical granulation. Thus, the spherical MWCNTs were most useful for the MWCNT monolith preparation with the SPS process and its application as a bone substitute material and a bone tissue engineering scaffold material was suggested.

Keywords: Carbon nanotube, spark plasma sintering, elastic modulus, hardness

DOI: 10.3233/BME-2009-0558

Journal: Bio-Medical Materials and Engineering, vol. 19, no. 1, pp. 11-17, 2009