Vol. 7, Issue 1 (2018)

Author(s):
Naseem AR Deshpande, Mandar A Kulkarni and Sanjay D Chakane

Abstract:
Formaldehyde is a carcinogenic VOC and its extensive usage in household and industries leads to overexposure. As per WHO statement, exposure limit of formaldehyde should not exceed 0.78 ppm per 30 min. The present work reports the study of doped polyaniline (PANI) as a formaldehyde sensor at room temperature. The polyaniline was synthesized by chemical oxidative polymerization from monomer aniline and ammonium persulfate (APS) as an oxidant and HCl, HClO₄ and HNO₃ acid as dopants. The prepared doped polyaniline samples were characterized using XRD, SEM and FTIR characterization technique. Subsequently, the prepared polyaniline samples were developed in the form of pellets for formaldehyde sensing studies. A two-probe gas sensing assembly was built to monitor the resultant changes in electrical resistance on exposure to formaldehyde (2 ppm) at room temperature. It was inferred that Polyaniline doped with HNO3 exhibits a good candidature for Formaldehyde sensing.