Pressure and temperature induced electrical resistance change in nano-carbon/epoxy composites

Enthalten in
Composites science and technology 
Volume
115
Start Page
1
End Page
8
Citation
Composites Science and Technology (115): 1-8 (2015-08-02)
Publisher DOI
10.1016/j.compscitech.2015.04.016
Scopus ID
2-s2.0-84928685748
Publisher
Elsevier
In this study, we investigate the changes of electrical resistance of the carbon black (CB) and carbon nanotube (CNT) filled epoxy composites upon compression, swelling and temperature variation. For all samples we observe a decrease of electrical resistance under compression, while an increase of electrical resistance is found upon swelling due to water absorption. With the same volumetric change, the CB/epoxy composites have a more pronounced change of electrical resistance than the CNT/epoxy composites. The influence of temperature variations on the overall electrical resistance is somewhat more complex. At low temperatures, electrical resistance clearly decreases with increasing temperature, mainly owing to the thermal fluctuation induced tunneling conduction mechanism. At high temperatures, electrical resistance decreases much slower and may even increase due to a more prominent thermal expansion effect. The thermal expansion of the epoxy matrix leads to a decrease of tunneling conduction. Without the contribution of the thermal expansion, the sensitivity and linearity of electrical resistance change upon temperature variations is higher.
Schlagworte
A. Carbon nanotubes
A. Polymer-matrix composites (PMCs)
B. Electrical properties
DDC Class
600: Technik
More Funding Information
The German Research Foundation (DFG) and its graduate school ‘‘Kunst und Technik’’ at the Technische Universität Hamburg-Harburg is gratefully acknowledged for financial support (DFG GRK 1006/1). The writing and organizing the content of this paper is carried out under the project number M21.7.11422 in the framework of the research program of the Materials innovation institute M2i, Delft, The Netherlands.