Sensitive conductive polymer nanocomposites from multiwalled carbon nanotube coated with polypyrrole and hydroxyl-terminated poly(butadiene-co-acrylonitile) polyurethane for detection of chloroform vapor

Abstract

Sensitive conductive polymer nanocomposites based on noncovalent interactions were prepared via combination of an in situ oxidative and stepwise polymerization, which consisted of multiwalled carbon nanotubes coated with polypyrrole and hydroxyl-terminated poly (butadiene-co-acrylonitile) polyurethane (MWCNTs@PPY/HTBN PU). The nanocomposites were fabricated into thin film sensors to detect CHCl3 vapor in environments. The experimental results indicated that the covering of PPY contributed to the improvement of the compatibility and conductivity of the composite systems, whereas the incorporation of the HTBN PU made for improving the dispersion behavior, the structural stability, the film-forming properties and vapor responsivity mainly triggered by the swelling of PU cross-linking networks. The vapor sensors could detect CHCl3 vapor as low as 50 ppm, and offered a wide vapor concentration range, good restorability and high vapor sensitivity of 0.055 at the CHCl3 concentration of 500 ppm. The cyclic sensing measurements showed good repeatability, stability and thus a great practical application prospect in detection of environmental gaseous pollutants.