Polyisoprene-multi-wall carbon nanotube composites for sensing strain

Carbon nanotubes offer attractive possibilities for developing new sensors because of superior mechanical and electrical properties. So far most studies relate the mechanical deformation to the change of nano-scale electrical properties. We present an attempt to use the multi-wall carbon nanotubes (MWCNT) to develop a new material for sensing macro-scale strain. Polymer composites containing dispersed nano-size particles, for example, polyisoprene - multi-wall carbon nanotube composites (PMCNTC) were prepared by treatment of the composite matrix with chloroform providing an increase of mobility and better dispersion of the nano-particles within the matrix. MWCNT with a small amount of solvent was carefully ground in a china pestle before adding to the polyisoprene matrix. Both the polyisoprene matrix solution and concentrated MWCNT product were mixed in a mixer with small glass beads at room temperature for 15 min. The product was dried at 40 degrees C for over 12 h and vulcanized under high pressure at 160 degrees C for 20 min. PMCNTC shows attractive tensile and compressive strain sensing properties. A mechanism of sensing effects is being investigated. (c) 2006 Elsevier B.V. All rights reserved.