Effect of polyaniline on the structural, conductivity, and dielectric properties of chitosan

• Main Authors: Nicole Ashley V. Santos, Maria Teresa R. Pulido, Doebner von C. Tumacder, Kathrina Lois M. Taaca
• Format: Article
• Language: English
• Published: Elsevier 2021-12-01
• Series: Carbohydrate Polymer Technologies and Applications
• Subjects: Conductivity; Dielectric; PANI; Chitosan; Dopants; Degree of oxidation
• Online Access: http://www.sciencedirect.com/science/article/pii/S2666893921000979

Polyaniline-chitosan (PANI-Cs) blends were prepared by in situ oxidative polymerization with acetic (CH3COOH) acid and hydrochloric (HCl) acid as dopants. Using Fourier transform infrared (FTIR) spectroscopy, the C N and C C stretching of quinoid and benzenoid of PANI in the PANI-Cs blends was confirmed at ranges 1528cm−1 to 1571cm−1 and 1490cm−1 to 1493cm−1, respectively. PANI emeraldine state was stipulated in all samples and PANI-Cs HCl samples have the highest degree of oxidation which is 48.56±0.23%. The ultraviolet-visible (UV–vis) spectroscopy identified the glucopyranose of Cs (282–308 nm), and π−π* transition of benzenoid (389–437 nm) and quinoid rings (551–554 nm) of PANI. The PANI-Cs blends yielded optical band gap values of 1.968±0.014 to 2.009±0.005 eV due to the presence of PANI. One-way ANOVA was also performed, and results showed the significant effect of using different dopants towards the degree of oxidation of the samples. Frequency dependent behavior was observed to the PANI-Cs samples with AC conductivity values around 1.2–4.1 Scm−1 at 105–107 Hz. The 102 Hz dielectric peak intensity of the samples varied due to influence of dopants on charge polarization. Lastly, PANI-Cs samples showed dominance of DC loss and relaxation at low frequencies 10–103 Hz.