Kumar J.Choudhary A.Afzal M.SachinPhor L.Chahal S.Dhawan S.K.Singh D.Kumar D.Singh S.P.Chaudhary V.Mahidol University2025-04-012025-04-012025-03-01Journal of the Electrochemical Society Vol.172 No.3 (2025)00134651https://repository.li.mahidol.ac.th/handle/123456789/108492We explored the in situ and real-time monitoring of the electric dipolar relaxation during the interaction of ammonia (NH3) gas, a crucial phenomenon in the gas sensing mechanism of conducting polymers, with dodecyl-benzene-sulfonic acid (DBSA)-doped polyaniline (PANI) nanocomposite polymer thin films. Dielectric spectroscopy from 20 Hz to 100 MHz was performed to analyze the dynamical behavior of the interaction process of DBSA-doped PANI nanocomposite polymer thin film with NH3 molecules. Initially, with no NH3 gas, the dielectric measurement showed a negative relative dielectric constant (about −6500 at 20 Hz) at low frequencies, indicating the conducting nature of unadorned DBSA-doped PANI nano-composite thin film (PANI-DBSA). On exposing PANI-DBSA film to NH3, the low frequency dipolar relaxation process was observed in the dielectric spectra. A shift toward the high frequency as a function of NH3 exposure time was observed, elucidating a continuous increase in dielectric strength and density of dipoles in the composite film with increasing exposure time which allows the gas a deeper penetration into the film and hence the increase in the density of dipoles. Removal of NH3 gas from PANI-DBSA allowed the system to retain its previous state,which is significant for sensing applications.Materials ScienceEnergyChemistryPhysics and AstronomyArticleSCOPUS10.1149/1945-7111/adbdf82-s2.0-10500044619119457111