Abstract

Tetraethyl orthosilicate (TEOS) was used as a chemical precursor to deposit ultra-thin SiO_xC_y plasma polymer films onto mild steel surfaces for preventing the corrosion process. The structure–property relationships of the coatings were evaluated by X-ray Photo Spectroscopy (XPS), X-Ray Diffraction (XRD), Fourier Transform InfraRed spectroscopy (ATR-FTIR) and Energy Dispersive X-ray spectroscopy (EDX) completed with Scanning Electron Microscopy (SEM). The SEM micrographs confirmed a pinhole-free surface morphology of the low-pressure deposited plasma polymer films. The TEOS molecules become fragmented in the plasma by numerous collisions with energy-rich electrons and heavier particles. Recombination of fragments and condensation onto the steel substrate is responsible for the formation of organic SiO containing plasma polymer layers. Such thin layers consist of predominantly SiO_x structures. Their properties are determined largely by the gap distance between the two samples used as electrodes in the plasma. The efficiency of the corrosion-protecting coating was compared with uncoated samples. The corrosion protection was determined by exposure of samples to 3.5% NaCl aqueous solutions. For this purpose, polarization and Electrochemical Impedance Spectroscopy (EIS) were used to monitor the corrosion. The optimal gap distance between the electrodes was determined for corrosion protection. The best protective efficiency reached more than 97% of the total protection as measured at room temperature.

摘要

原硅酸四乙酯 (TEOS) 用作化学前驱体以沉积超薄 SiO _x C _y等离子聚合物薄膜覆盖在低碳钢表面上，以防止腐蚀过程。通过 X 射线照片光谱 (XPS)、X 射线衍射 (XRD)、傅立叶变换红外光谱 (ATR-FTIR) 和能量色散 X 射线光谱 (EDX) 评估涂层的结构 - 性能关系，并通过扫描完成电子显微镜（SEM）。SEM 显微照片证实了低压沉积的等离子体聚合物膜的无针孔表面形态。TEOS 分子在等离子体中通过与富含能量的电子和较重粒子的多次碰撞而破碎。碎片的重组和凝结在钢基材上是形成含有等离子聚合物层的有机 SiO 的原因。这种薄的层由主要的SiO _X结构。它们的特性很大程度上取决于用作等离子体中电极的两个样品之间的间隙距离。将防腐涂层的效率与未涂层的样品进行比较。通过将样品暴露于 3.5% NaCl 水溶液中来确定腐蚀保护。为此，使用极化和电化学阻抗谱 (EIS) 来监测腐蚀。确定电极之间的最佳间隙距离以进行腐蚀保护。在室温下测得的最佳保护效率达到总保护的 97% 以上。