Investigation of thermal stability studies of MWCNT-conducting polymer based composites for heat sensing application

Abstract: Composites of multiwall carbon nanotubes (MWNTs), electrically conducting polymers like polyaniline (PANI), and poly (3, 4-ethylenedioxythiophene)–polystyrene sulfonic acid (PEDOT: PSS) were prepared by following solution casting method. MWCNTs were functionalized with oxidative acid (5M HNO3) treatment schemes to improve the adhesion between the polymer and carbon nanotubes by a п-п stacking interaction. Structural and morphological characterization of composites has been carried out by means of Field emission scanning electron microscope (FESEM) and High resolution transmission electron microscope (HRTEM). A detailed temperature dependent resistance study of both the composites was performed to examine the thermal properties of both the composites. MWCNT-PEDOT: PSS composite was found to show improved thermal stability than MWCNT-PANI composite hence was expected as the better candidate for heat sensor applications. MWCNT-PEDOT: PSS composite was further evaluated for its heat sensing response and was found to show excellent response, less response and recovery time and good reproducibility up to 190 0 C where the polymer film without MWCNTs was found to show the same results up to 100 0 C only.