Table 3.

Impedance parameters for CS in 4 M HCl free and containing various concentrations of the prepared inhibitors at room temperature.

Inh	Conc. M	RS (Ω.cm2)	CPE		Rct (Ω.cm2)	Rf (Ω.cm2)	RP (Ω.cm2)	Cdl, (F/cm2) × 10–9	τ, (s)	χ2 × 10–3
			n	Y° (μF)
–	Blank	2.386 ± 1.02	0.8532 ± 0.07	418.18 ± 1.45	35.24 ± 3.13	–	35.24 ± 1.15	65.81	0.0134	4.013	–
DCSM-8	1 × 10–6	2.707 ± 0.91	0.8525 ± 0.08	62.29 ± 1.27	545.53 ± 2.05	8.24 ± 0.15	553.77 ± 1.06	9.75	0.030	3.241	93.64
	1 × 10–5	4.488 ± 0.80	0.8488 ± 0.07	22.57 ± 1.35	628.64 ± 3.14	9.31 ± 0.09	637.95 ± 1.33	8.46	0.038	2.847	94.48
	5 × 10–5	5.419 ± 0.72	0.8379 ± 0.03	17.33 ± 2.02	704.24 ± 3.42	12.52 ± 0.08	716.76 ± 2.20	6.28	0.050	2.771	95.08
	1 × 10–4	6.230 ± 1.13	0.8303 ± 0.09	13.53 ± 1.93	832.3 ± 4.06	16.33 ± 0.08	848.63 ± 1.13	3.62	0.058	1.984	95.85
	5 × 10–4	6.809 ± 0.92	0.8232 ± 0.08	11.39 ± 2.28	891.47 ± 2.65	19.84 ± 0.14	911.31 ± 3.05	3.04	0.064	0.859	96.13
	1 × 10–3	7.687 ± 0.85	0.8095 ± 0.06	8.25 ± 3.30	982.88 ± 4.12	21.27 ± 0.17	1004.15 ± 2.17	1.63	0.072	1.221	96.49
DCSM-10	1 × 10–6	4.702 ± 1.14	0.8265 ± 0.12	49.48 ± 2.15	593.32 ± 1.55	9.11 ± 0.07	602.43 ± 2.21	7.57	0.071	2.230	94.15
	1 × 10–5	4.915 ± 0.76	0.8367 ± 0.08	18.24 ± 2.34	684.48 ± 1.96	11.34 ± 0.14	695.82 ± 2.50	7.02	0.083	2.182	94.94
	5 × 10–5	5.296 ± 0.90	0.8452 ± 0.16	16.08 ± 1.86	768.54 ± 2.77	17.02 ± 0.09	785.56 ± 1.37	6.11	0.088	1.873	95.51
	1 × 10–4	4.805 ± 1.04	0.8388 ± 0.09	10.43 ± 3.10	872.42 ± 1.69	20.16 ± 0.19	892.58 ± 2.26	3.06	0.091	1.624	96.05
	5 × 10–4	4.937 ± 0.82	0.8456 ± 0.09	8.86 ± 1.79	963.72 ± 2.60	24.41 ± 0.16	988.13 ± 3.09	2.24	0.094	0.937	96.43
	1 × 10–3	5.602 ± 0.68	0.8456 ± 0.08	7.10 ± 2.46	1087.59 ± 3.15	28.97 ± 0.08	1116.56 ± 1.14	1.41	0.103	0.881	96.84
DCSM-12	1 × 10–6	4.209 ± 0.87	0.8234 ± 0.06	21.17 ± 3.06	676.75 ± 2.51	10.28 ± 0.07	687.03 ± 3.05	4.42	0.166	2.024	94.87
	1 × 10–5	5.413 ± 0.96	0.8345 ± 0.03	13.69 ± 3.44	788.73 ± 3.20	13.32 ± 0.13	802.05 ± 3.36	3.65	0.193	1.883	95.61
	5 × 10–5	4.722 ± 1.08	0.8133 ± 0.08	11.11 ± 2.71	894.53 ± 2.07	19.21 ± 0.08	913.74 ± 2.32	3.21	0.215	1.540	96.14
	1 × 10–4	4.226 ± 0.95	0.8345 ± 0.07	9.58 ± 2.32	1018.73 ± 4.11	23.25 ± 0.08	1041.98 ± 2.27	2.81	0.266	0.802	96.62
	5 × 10–4	7.287 ± 1.21	0.8187 ± 0.11	8.04 ± 1.52	1108.53 ± 3.21	27.08 ± 0.12	1135.61 ± 1.56	1.46	0.293	0.626	96.90
	1 × 10–3	7.578 ± 0.86	0.8096 ± 0.09	6.78 ± 1.77	1214.17 ± 2.33	31.37 ± 0.11	1245.54 ± 1.72	0.35	0.303	0.792	97.17