Effect of Caffeine-Zn2+ System in Preventing Corrosion of Carbon Steel in Well Water
Figure 3
2D AFM images of the surface of (a) polished carbon steel (control), (b) carbon steel immersed in well water (blank), (c) carbon steel immersed in well water containing caffeine (200 ppm)-Zn2+ (50 ppm), and (d) carbon steel immersed in well water containing caffeine (200 ppm)-Zn2+ (50 ppm)-malic acid (25 ppm). 3D AFM images of the surface of (e) polished carbon steel (control), (f) carbon steel immersed in well water (blank), (g) carbon steel immersed in well water containing caffeine (200 ppm)-Zn2+ (50 ppm), and (h) carbon steel immersed in well water containing caffeine (200 ppm)-Zn2+ (50 ppm)-malic acid (25 ppm). The cross sectional profiles, which are corresponding to as shown broken lines in AFM images of (i) polished carbon steel (control), (j) carbon steel immersed in well water (blank), (k) carbon steel immersed in well water containing caffeine (200 ppm)-Zn2+ (50 ppm), and (l) carbon steel immersed in well water containing caffeine (200 ppm)-Zn2+ (50 ppm)-malic acid (25 ppm).
