Fabrication of DBSA-doped PANI–PVC composites via inverse emulsion polymerization for electrochemical detection of ascorbic acid

Polyaniline (PANI) is a well-known conducting polymer recognized for its tunable electrical conductivity and structural versatility. In this work, DBSA-doped PANI–PVC composites were synthesized using inverse emulsion polymerization to improve their physicochemical and electrochemical properties. The composites were characterized using ultraviolet–visible (UV/Vis) spectroscopy, Fourier-transform infrared (FTIR) spectroscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM). UV/Vis spectra confirmed the emeraldine salt (ES) form of PANI, indicating successful doping and integration within the PVC matrix, while FTIR supported the incorporation of DBSA as a dopant. Electrical conductivity increased with decreasing PVC content, with optimal performance observed at 3% PVC. XRD patterns suggested reduced compatibility between PANI and PVC at higher PVC concentrations. SEM images of the DBSA/PANI-PVC 3% composite showed a rough, compact, and porous morphology, in contrast to the smooth surface of pure PANI. TGA results indicated enhanced thermal stability of the DBSA/PANI-PVC 3% composite compared to pure PANI. Cyclic voltammetry (CV) at various scan rates and concentrations demonstrated improved electrochemical sensing performance of the DBSA/PANI-PVC 3% composite, highlighting its potential for use in ascorbic acid (AA) detection.Graphical Abstract