Table 2 EIS parameters of steel plates submerged in saline solution with and without extracts of CPA and HQZn-PA for up to 48 h.
Sample | Time/day | Rs (Ω cm2) | Rf (Ω cm2) | CPEf (× 10–3) (F) | nf | Rct (Ω cm2) | CPEdl (× 10–5) (F) | ndl |
|---|---|---|---|---|---|---|---|---|
Blank | 1 | 12.48 | – | – | – | 650.2 | 107.5 | 0.81 |
4 | 12.15 | – | – | – | 1320 | 93.7 | 0.79 | |
24 | 11.64 | – | – | – | 1176 | 176.6 | 0.75 | |
48 | 10.43 | – | – | – | 1120 | 217.7 | 0.69 | |
CPA extract | 1 | 12 | – | – | – | 675 | 75.2 | 0.82 |
4 | 12.65 | – | – | – | 856 | 61.2 | 0.85 | |
24 | 12.95 | 175 | 0.73 | 0.83 | 1710 | 39.34 | 0.85 | |
48 | 11.28 | 85 | 1.65 | 0.91 | 1071 | 24.4 | 0.81 | |
HQZn-PA extract | 1 | 413 | – | – | – | 1248 | 8.88 | 0.81 |
4 | 395 | – | – | – | 1452 | 5.75 | 0.89 | |
24 | 387 | 98 | 1.38 | 0.99 | 2508 | 4.74 | 0.91 | |
48 | 371 | 141 | 1.15 | 0.94 | 5143 | 4.51 | 0.89 |
