Electrochemical Deposition of Polyaniline on Carbon Steel for Corrosion Study in Geothermal Solution
| Autor: | Gabriela Aristia, Le Quynh Hoa, Ralph Baessler |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
Materials science
Carbon steel 020209 energy Mechanical Engineering Oxalic acid 02 engineering and technology Electrolyte engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics Corrosion Dielectric spectroscopy chemistry.chemical_compound chemistry Mechanics of Materials Polyaniline 0202 electrical engineering electronic engineering information engineering engineering General Materials Science 0210 nano-technology Polarization (electrochemistry) Dissolution Nuclear chemistry |
| Zdroj: | Materials Science Forum. 966:107-115 |
| ISSN: | 1662-9752 |
| DOI: | 10.4028/www.scientific.net/msf.966.107 |
| Popis: | Polyaniline has been widely developed for many applications, e.g., sensor, supercapacitor component, electrochromic devices, and anticorrosion pigments [1]. Although the addition of polyaniline pigment in organic coatings has been an alternative for corrosion protection in industrial application, the protection mechanism is still not fully understood [2]. Herein in this study, as a part of the development of polyaniline/silicon dioxide coating for geothermal application, polyaniline has been deposited electrochemically on carbon steel surface and tested in geothermal solution to study the contribution of polyaniline in the corrosion protection of a polyaniline-based composite in the geothermal system. The electrochemical deposition was carried out by immersing carbon steel in 0.1 M oxalic acid and 0.05 M aniline, with the polarization potential of -0.6 – 1.5 V vs. Ag/AgCl, and a scan rate of 10 mV/s. To observe the surface/interface reaction between the electrolyte and electrode surface during the electrochemical polymerization, electrochemical impedance spectroscopy (EIS) measurement was applied after each cycle. For corrosion study in the geothermal application, this experiment used an artificial geothermal solution with the composition of 1,500 mg/l Cl-, 20 mg/l SO42-, 15 mg/l HCO3-, 200 mg/l Ca2+, 250 mg/l K+, and 600 mg/l Na+, and pH 4 to simulate a geothermal brine found in Sibayak, Indonesia. Electrochemical measurements were performed by monitoring the open circuit potential over seven days, with the interruption of EIS every 22 hours. The experiments were performed at room temperature and 150 °C (1 MPa) in a free oxygen environment. Polyaniline coated carbon steel is more durable in a room temperature environment compared to 150 °C, which could be caused by the iron oxalate dissolution at elevated temperature. This degradation was further proven by the impedance spectra, which showed a reduction of approximately ten times for specimens measured at 150 °C as compared to the specimens measured at room temperature. |
| Databáze: | OpenAIRE |
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