Comparatively electrochemical studies at different operational temperatures for the effect of nanoclay platelets on the anticorrosion efficiency of DBSA-doped polyaniline/Na⁺–MMT cla

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• 作者：Kung-Chin Chang ; Guang-Way Jang ; Chih-Wei Peng ; Chang-Yu Lin ; Jen-Chyuan Shieh ; Jui-Ming Yeh ; Jen-Chang Yang ; Wen-Tyng Li
• 关键词：Polyaniline ; Clay ; Nanocomposite ; Corrosion ; Emulsion polymerization
• 刊名：Electrochimica Acta
• 出版年：2007
• 出版时间：30 April 2007
• 年：2007
• 卷：52
• 期：16
• 页码：5191-5200
• 全文大小：1031 K

文摘

In this paper, DBSA-doped polyaniline (PANI)/Na⁺–montmorillonite (MMT) clay nanocomposite (PCN) materials have been successfully prepared with dodecylbenzenesulfonic acid (DBSA) as emulsifier and dopant for the emulsion polymerization of aniline. The as-prepared DBSA-doped samples were subsequently characterized by FTIR spectroscopy, WAXRD patterns and TEM. It should be noted that the nanocomposite coating containing 1 wt. % of clay loading was found to exhibit an observable enhanced corrosion protection on cold-rolled steel (CRS) electrode at higher operational temperature of 50 °C, which was even better than that of uncoated and electrode-coated with PANI alone at room temperature of 30 °C based on the electrochemical parameter evaluations (e.g., E_corr, R_p, I_corr, R_corr and impedance). In this work, all electrochemical measurements were performed at a double-wall jacketed cell, covered with a glass plate, through which water was circulated from a thermostat to maintain a constant operational temperature of 30, 40 and 50 ± 0.5 °C. Moreover, a series of electrochemical parameters shown in Tafel, Nyquist and Bode plots were all used to evaluate PCN coatings at three different operational temperatures in 5 wt. % aqueous NaCl electrolyte. Effect of material composition on the molecular weight and optical properties of neat PANI and PCN materials, in the form of solution, were studied by gel permeation chromatography (GPC) and UV–vis spectra, respectively. Finally, electrical conductivity at three different operational temperatures of PANI and PCN powder-pressed pellets doped with different inorganic acids such as HCl, HNO₃ and H₂SO₄ was also investigated through the measurements of standard four-point-probe technique.