Giant dielectric constant and resistance-pressure sensitivity in carbon nanotubes/rubber nanocomposites with low percolation threshold

Nanocomposites consisting of methylvinyl silicone rubber (VMQ) with excellent elasticity as polymer matrix and multiwall carbon nanotube (MWNT) with large slenderness ratio and high conductivity as filler were fabricated by a solution method and subsequently hot pressing technology. Studies on dielectric property and resistance-pressure sensitivity of the MWNT/VMQ composites showed that there was a giant dielectric constant and significant resistance-pressure sensitivity as the concentration of MWNT was near a low percolation threshold, f(c)approximate to 0.012. After the composite applied an enough pressure for long time, the resistance-pressure sensitivity still shows an excellent reproducibility due to the good dispersion and low loading of MWNT. (c) 2007 American Institute of Physics.