Polymer Nanocomposite Films as a Potential Sensor

Abstract

Polymer composites using carbon nanotubes (CNTs) are fast growing class of materials since CNTs exhibit a high aspect ratio, unique electrical, mechanical and structural properties which contribute to novel characteristics for engineering applications such as actuators, hydrogen storage, chemical sensors and nanoelectronic devices. Several papers have been published utilizing CNTs as the sensing material in pressure, flow, thermal, gas, optical, mass, strain, stress, chemical and biological sensors. Amongst many of its superior electro-mechanical properties, piezoresistive effect in CNTs is attractive for sensor design. When CNTs are subjected to a mechanical strain, a change in its chirality leads to modulation of its conductance. For this investigation, biocompatible polymer matrices prepared using PMMA and PCL were used to provide good interfacial bonding between VNTs. MWCNT mixed in 0.2, 0.5 and 1.0 % w/w content were used for the preparation of polymer nanocomposites. PMMA-based nanocomposites were prepared via the mixing of the MWCNT and polymer in a dichloromethane solution, while for the PCL-based nanocomposites as a solvent tetra-hyrofurane was used. Characterization of the nanocomposite films was performed by DSC, TGA, WAX, FTIR and SEM, as well as electrical measurements. Sensor activity was followed through the changes in the electrical conductivity of the nanocomposite films indicating that MWCNT into polymer matrix significantly changes their properties.