This paper reports on electrical resistance vs. aging time for the response of polyaniline films under exposure to water, ethanol and nitric acid （HNO3） solution. Camphor sulfonic acid-doped polyaniline films were p...This paper reports on electrical resistance vs. aging time for the response of polyaniline films under exposure to water, ethanol and nitric acid （HNO3） solution. Camphor sulfonic acid-doped polyaniline films were prepared by a ＂doping-dedoping-redoping＂ method, the morphology and microstructures of the films were characterized by a scanning electron microscope and an x-ray diffractometer, the electrical resistance was measured by a four-probe method. It was found that a lower amount of water molecules infiltrating the film can decrease the film＇s resistance possibly due to an enhancement of charge carrier transfer between polyaniline chains, whereas excessive water molecules can swell inter-chain distances and result in a quick increase of resistance. The resistance of the film under exposure to ethanol increases and becomes much larger than the original value. However, HNO3 solution can decrease the film＇s resistance sharply possibly owing to doping effect of protonic acid. These results can help to understand the conduction mechanism in polyaniline films, and also indicate that the films have potential application in chemical sensors.展开更多
Polyaniline (PANI) film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte. The potential sweep rates were changed to achieve the PANI film with dif...Polyaniline (PANI) film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte. The potential sweep rates were changed to achieve the PANI film with different thickness and structures. Protective properties of the PANI film for corrosion of stainless steel in 3% NaCl aqueous solution were investigated by monitoring potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that the PANI film which was formed with lower sweep rate led to more positive shift of corrosion potential and greater charge transfer resistance, reflecting higher inhibition for corrosion of the stainless steel.展开更多
基金Project supported by the Program for New Century Excellent Talents in University of China(Grant No.NCET-07-0472)the National Natural Science Foundation of China(Grant Nos.10604038 and 10910101081)
文摘This paper reports on electrical resistance vs. aging time for the response of polyaniline films under exposure to water, ethanol and nitric acid （HNO3） solution. Camphor sulfonic acid-doped polyaniline films were prepared by a ＂doping-dedoping-redoping＂ method, the morphology and microstructures of the films were characterized by a scanning electron microscope and an x-ray diffractometer, the electrical resistance was measured by a four-probe method. It was found that a lower amount of water molecules infiltrating the film can decrease the film＇s resistance possibly due to an enhancement of charge carrier transfer between polyaniline chains, whereas excessive water molecules can swell inter-chain distances and result in a quick increase of resistance. The resistance of the film under exposure to ethanol increases and becomes much larger than the original value. However, HNO3 solution can decrease the film＇s resistance sharply possibly owing to doping effect of protonic acid. These results can help to understand the conduction mechanism in polyaniline films, and also indicate that the films have potential application in chemical sensors.
文摘Polyaniline (PANI) film was electrosynthesized on 304 stainless steel by cyclic voltammetry using aqueous oxalic acid as supporting electrolyte. The potential sweep rates were changed to achieve the PANI film with different thickness and structures. Protective properties of the PANI film for corrosion of stainless steel in 3% NaCl aqueous solution were investigated by monitoring potentiodynamic polarization curves and electrochemical impedance spectroscopy (EIS). The results showed that the PANI film which was formed with lower sweep rate led to more positive shift of corrosion potential and greater charge transfer resistance, reflecting higher inhibition for corrosion of the stainless steel.
