SYNTHESIS OF POLYANILINE ON GRAPHITE SUBSTRATE WITH CONTROLLED-CURRENT PULSED-ELECTROPOLYMERIZATION

• Main Author: Manuel Setiawan, Kevin
• Format: Final Project
• Language: Indonesia
• Subjects: Kimia
• Online Access: https://digilib.itb.ac.id/gdl/view/65698
• Institution: Institut Teknologi Bandung

Polyaniline (PANI) is an organic polymer with good conductivity and electrocatalytic activity. Therefore, PANI is an important material in supercapacitor, battery, fuel cell, solar cell, and many more. These devices needed the conducting form of polyaniline, which is polyaniline emeraldine salt (PANI ES). Conventional methods of PANI ES polymerization employ oxidating agent via two-phase emulsion system, or rapid mixing in aqueous solution. Both methods require low temperature condition, isolation/purification, and fabrication to produce the desired PANI ES film. An alternative method uses electrical work to drive oxidative polymerization. Electropolymerization is a better alternative that deposits PANI ES to a conducting substrate with high purity. In this work, PANI ES was synthesized using pulse electropolymerization. Electropolymerization was set to the controlled-current mode to control the polymerization rate of aniline into polyaniline. PANI ES with various electropolymerization duration was produced and analyzed to determine the growth rate of PANI ES film. Electropolymerization was carried out in a cell with a DC Source and a DC Load that are connected in series. The electropolymerization cell consists of synthetic graphite films as both cathode and anode. When driving potential was applied using the DC Source across the system, the DC Load sinks the driving potential into a controlled-current pulse. The initial current pulse oxidizes aniline into aniline oligomers, which is deposited in the anode. The following pulses promote oligomer growth into polyaniline. The deposited film was then characterized with Raman and ATR-IR spectroscopy. Raman shift and IR absorbance peaks confirmed the presence of benzenoid and quinonoid groups, which are the characteristics of PANI ES. Conductive PANI ES film was further identified from the polaronic C-N vibration peak in the IR and Raman spectra, and the presence of the polaronic band in the IR absorption spectrum. Controlled rate of electropolymerization was found after measuring the thickness of films at various electropolymerization duration. It was found that PANI ES film had a linear growth after 180 s of controlled-current pulse electropolymerization