Electrical And Optical Properties Of Conducting Polymer: Polypyrrole And Polyaniline Blends

Abstract

This dissertation aimed to study the electrical and optical properties of conducting polymer blends of polypyrrole (PPy) and Polyaniline (PANI). Polymer blend was a combination of two or more polymers to make a new product with unique properties. The properties of the blends depend on the miscibility of the polymer to each other. Study the effect of miscibility on the optical and electrical properties of polymer blends of common polymers PANI and PPy. Chapter 4: This report was on the miscibility and phase behavior of polypyrrole-polyaniline (PPy-PANI) as a various function of blend compositions. The PPy-PANI blends were prepared by solution processing method, using dimethyl sulfoxide (DMSO) solvent. The synthesized polymer blends were characterized based on the data analysis from FT-IR, XRD, and DSC. The PPy-PANI system was successful to form blends in the DMSO solvent. The polymer blends showed almost amorphous nature in XRD spectra because of intermolecular interaction between PPy and PANI macromolecules, which was confirmed by FT-IR data. Specifically, the DSC result for the PPY: PANI= 50:50 wt.% blend showed only one glass transition temperature (Tg), which indicates that the two polymers are well miscible without undergoing any phase separation. Chapter 5.1: This work aims to present the optical and thermal study on doped and dedoped polyaniline (PANI) nanoparticles. Herein, PANI nanoparticles are successfully synthesized by chemical oxidative polymerization of aniline in the presence of hydrochloric acid and ammonium persulphate as oxidant. Then PANI power samples are characterized by FT-IR, XRD, TGA, and UV-Vis. The crystallinity of doped PANI is significantly decreased once it is dedoped. The average crystallite size of PANI is estimated to be ca. 24.27 nm based on Scherrer’s equation. The optical absorption peaks of transition are observed at 337 nm and 320 nm for doped and dedoped PANI, respectively. Chapter 5.2: This work aimed to study the polymer-blend morphologies, electrical and optical properties of PPy/PANI materials. The polymer blends have been developed by varying the ratio of the constituent polymer. The characteristic techniques, SEM-EDX, UV-Vis, PL, and I-V were applied to study the blends. The result determines the optical band gap of different composition of the blends were in the range of 1.53-1.95 eV. The chemical composition of the PPy/PANI blends materials were determined. Finally, the electrical transport and the conductivity of the blend observed in the range of 10-6 to 10-3 S/cm at room temperature. The PPy/PANI blend has exhibits a semiconductor behavior. Chapter 6: This paper reported that the preparation of a thin film of pure PANI and PPy-PANI blend on Indium Tin Oxide (ITO) substrate by using the drop-casting xvii method. Investigated an application of the blend as an electrode material. Cyclic Voltammetry (CV) indicated that the PPy/PANI blend has an ideal capacitive behavior. Electrochemical impedance spectroscopy (EIS) and Galvanostatic charge-discharge (GCD) measurements proved that the blend electrode with composition PPy: PANI = 50:50+0.01SDS showed that the lower value of ESR, no semicircle was observed and the highest areal specific capacitance (134.36 F.cm 2 at 0.1 mA.cm-2 ) compared to other compositions. The electrochemical studies of PPy-PANI blends showed that PPy-PANI blends were suitable materials for electrodes of the supercapacitors.