Reinforcement of Polymers with Carbon Nanotubes:  The Role of Nanotube Surface Area

• Published in: Nano letters Vol. 4; no. 2; pp. 353 - 356
• Main Authors: Cadek, M, Coleman, J. N, Ryan, K. P, Nicolosi, V, Bister, G, Fonseca, A, Nagy, J. B, Szostak, K, Béguin, F, Blau, W. J
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.02.2004
• Subjects: Condensed matter: structure, mechanical and thermal properties; Cross-disciplinary physics: materials science; rheology; Deformation and plasticity (including yield, ductility, and superplasticity); Exact sciences and technology; Materials science; Mechanical and acoustical properties of condensed matter; Mechanical properties of solids; Nanoscale materials and structures: fabrication and characterization; Nanotubes; Physics; Tensile tests; Carbon nanotubes; Experimental study; Coatings; Thin films; Interfaces; Young modulus; Composite materials; Polyvinyls; Reinforcement; Surface area; Nanostructured materials; Organic compounds
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/nl035009o

Tensile tests were carried out on free-standing composite films of poly(vinyl alcohol) and six different types of carbon nanotubes for different nanotube loading levels. Significant increases in Young's modulus by up to a factor of 2 were observed in all cases. Theories such as the rule-of-mixtures or the Halpin-Tsai-theory could not explain the relative differences between composites made from different tube types. However, it is possible to show that the reinforcement scales linearly with the total nanotube surface area in the films, indicating that low diameter multiwall nanotubes are the best tube type for reinforcement. In addition, in all cases crystalline coatings around the nanotubes were detected by calorimetry, suggesting comparible polymer−nanotube interfaces. Thus, the reinforcement appears to be critically dependent on the polymer−nanotube interfacial interaction as previously suggested.