ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Fabrication of a low-cost humidity sensor using polypyrrole composites containing Li₂O and ZnO nanoparticles

Rajshekar L. Madival, M. Prashantkumar, N. Nagaraja, Vinay V. Kannur, and Y. T. Ravikiran

Department of Physics, Rao Bahadur Y Mahabaleswarappa Engineering College, Ballari, India

E-mail: pacificmg@gmail.com

Received: 18 April 2023  Accepted: 27 November 2023

Abstract:

We report the structural properties and humidity sensing abilities of polypyrrole (PPy) composites containing ZnO nanoparticles (NPs) and Li₂O. The PPy was synthesized following chemical oxidation method. The PPy₅₀–ZnO(NPs)₅₀–Li₂O_x (where x = 0,2,4,6,8 & 10) composites were prepared by physical mixing using ball-milling method. The as-prepared composites were subjected to XRD, FTIR and EDAX. The structural analysis using these tools hinted at the presence of Li₂O in the composites and the effect of variation of Li₂O in the composites is emphasized. The humidity sensing ability of pristine PPy and the composites has been investigated, at room temperature, by measuring the change in electrical resistance of the sample due to the variation in relative humidity from 11 to 97% RH. The response to humidity and recovery times were determined. The mechanism of humidity sensing in these composites was understood by Grotthus theory. Among all the composites, the composite x = 10 (PZL10) has exhibited very good response and recovery time and has the potential to be used as a low-cost and highly effective humidity sensor.

Keywords: Polypyrrole; Polymer composites; Humidity sensors; Nanoparticles

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-023-03240-1

Chemical Papers 78 (4) 2313–2321 (2024)