Year: 2026
Type: article
Abstract: This study investigates the electrostatic and electrochemical behavior of polyaniline (PANI) and its composite with amine-functionalized multi-walled carbon nanotubes (PANI/MWCNT–NH2) to elucidate the mechanisms governing ammonia (NH3) sensing. High-resolution atomic force microscopy (AFM) coupled with electrostatic force microscopy (EFM) demonstrates that pristine PANI forms granular macroaggregates with localized charge distribution, whereas MWCNT incorporation promotes worm-like percolative networks that enhance charge delocalization and conductivity. Electrochemical characterization by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) corroborates these nanoscale observations, revealing significantly improved interfacial electron transfer kinetics in the composite. Upon exposure to NH3, pristine PANI undergoes rapid de-doping and nonlinear signal suppression, while the composite exhibits a more progressive electrochemical modulation. Overall, the results demonstrate that NH3 sensing in PANI-based films is governed not solely by electroactive material content but by the interplay between nanoscale morphology, electrostatic heterogeneity, and charge transport topology. The nanotube-mediated formation of delocalized and percolative conductive pathways provides structural and electrochemical robustness, enabling tunable, high-sensitivity operation suitable for next-generation, low-power ammonia sensing platforms.
Source: Sensors
DOI: 10.3390/s26072169
Language: English
Subfield: Polymers and Plastics
Field: Materials Science
Domain: Physical Sciences
Open Access status: gold
Estimated APC paid: $3,137
OpenAlex ID: W7146957612