Uniform polyaniline (PANI) nanotubes were synthesized by a self-assembly method under relatively dilute hydrochloric acid (HCl) solution. Scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and UV-Vis-NIR spectroscopy were employed to characterize the morphology and molecular structure of the PANI products. SEM images show that the PANI nanotubes have uniform morphology and form compact coating on the substrate surface. For comparison, aggregated PANI was also synthesized by conventional polymerization method. The performance of the PANI products on carbon steel was studied using eletrochemical measurement and immersion corrosion experiment in 3.5 wt% NaCl aqueous solution. The corrosion potentials of carbon steel samples increase by 0.196 V and 0.060 V after coated with PANI nanotubes and aggregated PANI, respectively, and the corrosion currents density decrease by about 76.32% and 36.64%, respectively. The 6-day immersion experiment showed that the carbon steel samples coated by PANI nanotubes showed more excellent anticorrosion performance, because the more compact coating formed by PANI nanotubes may inhibit the corrosion process between the anodic and cathodic.

中文翻译：

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一维聚苯胺纳米管作为防腐涂层的制备

在相对稀的盐酸 (HCl) 溶液下通过自组装法合成了均匀的聚苯胺 (PANI) 纳米管。扫描电子显微镜 (SEM)、傅里叶变换红外 (FTIR) 光谱和紫外-可见-近红外光谱用于表征 PANI 产品的形态和分子结构。SEM 图像显示 PANI 纳米管具有均匀的形态并在基板表面形成致密的涂层。为了比较，聚合聚苯胺也通过常规聚合方法合成。通过电化学测量和在 3.5 wt% NaCl 水溶液中的浸没腐蚀实验研究了 PANI 产品在碳钢上的性能。碳钢样品涂有聚苯胺纳米管和聚苯胺后，腐蚀电位分别增加了 0.196 V 和 0.060 V，腐蚀电流密度分别下降约 76.32% 和 36.64%。为期6天的浸泡实验表明，PANI纳米管涂层的碳钢样品表现出更优异的防腐性能，因为PANI纳米管形成的更致密的涂层可以抑制阳极和阴极之间的腐蚀过程。