Inhibition Effect of 1-Butyl-4-Methylpyridinium Tetrafluoroborate on the Corrosion of Copper in Phosphate Solutions

Figure 5

SEM micrographs of the surface of copper: (a) before, (b) after being immersed in 0.5 M PO⁴³⁻ (pH 2) for 24 hours, (c), (d) corrosive solution contained additionally 50.0 mM of 1-Butyl-4-methylpyridinium tetrafluoroborate of pH 4 and 2, respectively, after removal of the inhibiting film for pH: (e) 4 and (f) 2 (magnification 750x).

(a)

(b)

(c)

(d)

(e)

(f)