Effect of aspect ratio of multiwall carbon nanotubes on resistance-pressure sensitivity of rubber nanocomposites

To explore the effect of aspect ratio (AR) of nanotubes on conductivity and resistance-pressure sensitivity, four kinds of multiwall carbon nanotubes (MWNT) with different aspect ratios (AR=50, 75, 333, and 500) were dispersed into methylvinyl silicone rubber (VMQ) to fabricate the MWNT/VMQ nanocomposites. Results show that the composites with low concentration nanotubes at low AR value show great resistance-pressure sensitivity. High AR is not beneficial for the improvement of conductivity, and at the same concentration of MWNT, the composites with high AR tubes display large resistance-pressure sensitivity. The sensitivity is dependent on the quantity of conductive channels formed in the composites. (C) 2007 American Institute of Physics.