Conducting Polymer Films: A Comparative Study on Polyaniline–Cellulose Nanofibers Composite Film with and without Sorbitol Plasticizer

Polyaniline–cellulose nanofiber (PANI–CNF) composite films were created to examine how changing the aniline content and adding sorbitol affect their structure, electrical properties, and thermal behavior. Composite films containing 2[Formula: see text]wt.%, 5[Formula: see text]wt.%, and 10[Formula: see text]wt.% aniline were prepared with and without a fixed sorbitol content. Structural and spectroscopic tests using XRD, FTIR, Raman, and UV–Vis confirmed effective interaction among PANI chains, CNF backbones, and sorbitol molecules. Electrical measurements showed that the film with 5[Formula: see text]wt.% aniline and no sorbitol had the highest conductivity at 0.129[Formula: see text]S[Formula: see text]cm[Formula: see text]. The films with 2[Formula: see text]wt.% and 10[Formula: see text]wt.% aniline had conductivities of 0.047[Formula: see text]S[Formula: see text]cm[Formula: see text] and 0.114[Formula: see text]S[Formula: see text]cm[Formula: see text], respectively. Adding sorbitol increased film flexibility but reduced conductivity to 0.057[Formula: see text]S[Formula: see text]cm[Formula: see text] for the same composition. This indicates that plasticizer-induced chain mobility reduces the efficiency of charge transport through the conductive network. Thermal analysis showed that composites without sorbitol had greater stability, while those with sorbitol broke down at lower temperatures because of plasticization. Overall, this study demonstrates that independent control of aniline concentration and sorbitol content enables systematic tuning of electrical conductivity, mechanical flexibility, and thermal stability in PANI–CNF composite films. This makes these composites suitable for new flexible and sustainable electronic materials.