Thermal conductivity of MWCNT/epoxy composites: The effects of length, alignment and functionalization

• Published in: Carbon (New York) Vol. 50; no. 6; pp. 2083 - 2090
• Main Authors: Park, Jin Gyu, Cheng, Qunfeng, Lu, Jun, Bao, Jianwen, Li, Shu, Tian, Ying, Liang, Zhiyong, Zhang, Chuck, Wang, Ben
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.05.2012; Elsevier
• Subjects: Alignment; Bonding; Carbon; carbon nanotubes; Chemistry; Cross-disciplinary physics: materials science; rheology; epoxides; Exact sciences and technology; Fullerenes and related materials; diamonds, graphite; General and physical chemistry; Heat transfer; Materials science; Multi wall carbon nanotubes; Physics; Polymer matrix composites; Specific materials; Surface physical chemistry; temperature; Thermal conductivity; Walls; Interfaces; Electrical conductivity; Composite materials; Functionalization; Multiwalled nanotube; Ambient temperature; Carbon nanotubes; Thermal conductivity; Carbon
• ISSN: 0008-6223; 1873-3891
• DOI: 10.1016/j.carbon.2011.12.046

Carbon nanotubes (CNTs) show great promise to improve composite electrical and thermal conductivity due to their exceptional high intrinsic conductance performance. In this research, long multi-walled carbon nanotubes (long-MWCNTs) and its thin sheet of entangled nanotubes were used to make composites to achieve higher electrical and thermal conductivity. Compared to short-MWCNT sheet/epoxy composites, at room temperature, long-MWCNT samples showed improved thermal conductivity up to 55W/mK. The temperature dependence of thermal conductivity was in agreement with κ∝Tn (n=1.9–2.3) below 150K and saturated around room temperature due to Umklapp scattering. Samples with the improved CNT degree of alignment by mechanically stretching can enhance the room temperature thermal conductivity to over 100W/mK. However, functionalization of CNTs to improve the interfacial bonding resulted in damaging the CNT walls and decreasing the electrical and thermal conductivity of the composites.