Thermodynamic and Interfacial Properties of DTABr/CTABr Mixed Surfactant Systems in Ethanolamine/Water Mixtures: A Conductometry Study

Table 1

The degree of counterion binding, thermodynamic function, micellar composition, interaction parameters, and critical micelle concentration of the DTABr + CTABr in aqueous medium.

Temp (K)	𝛼DTABr	β	Δ𝐺^𝐸 (J/mol)	Δ𝐻𝑀 (J/mol)	Δ𝑆𝑀 (J/mol⋅K)	Δ𝐺𝑀 (J/mol)	𝜒1	𝛽12	𝑓DTABr	𝑓CTABr	cmc* (mM)
298.1	0.1	0.79	−1081.9	−1081.9	3.17	−2010.9	0.124	−4.02	0.046	0.940	0.824
	0.2	0.68	−893.1	−893.1	3.27	−1867.5	0.134	−3.11	0.097	0.946	0.923
	0.3	0.67	−818.2	−818.2	3.46	−1851.0	0.147	−2.64	0.146	0.944	1.003
	0.4	0.59	−1187.4	−1187.4	4.15	−2427.3	0.200	−2.99	0.147	0.887	1.102
	0.5	0.73	−1402.9	−1402.9	4.57	−2767.0	0.239	−3.12	0.166	0.837	1.150
	0.6	0.65	−1282.1	−1282.1	4.74	−2695.3	0.253	−2.71	0.225	0.836	1.401
303.1	0.1	0.75	−714.4	−714.4	2.52	−1479.1	0.090	−3.45	0.058	0.972	0.871
	0.2	0.68	−909.6	−909.6	3.39	−1937.8	0.142	−2.96	0.112	0.942	0.939
	0.3	0.65	−751.9	−751.9	3.34	−1766.0	0.139	−2.50	0.157	0.953	1.053
	0.4	0.72	−898.7	−898.7	3.83	−2061.4	0.173	−2.49	0.183	0.928	1.151
	0.5	0.70	−1299.9	−1299.9	4.48	−2659.3	0.230	−2.91	0.177	0.857	1.181
	0.6	0.69	−1243.8	−1243.8	4.70	−2668.7	0.253	−2.61	0.237	0.846	1.420
308.1	0.1	0.74	−686.0	−686.0	2.52	−1463.4	0.090	−3.25	0.067	0.973	0.885
	0.2	0.68	−595.6	−595.6	2.76	−1444.5	0.103	−2.51	0.131	0.973	0.983
	0.3	0.63	−415.1	−415.1	2.71	−1250.1	0.100	−1.79	0.234	0.982	1.135
	0.4	0.73	−761.1	−761.1	3.64	−1882.2	0.159	−2.22	0.207	0.945	1.193
	0.5	0.71	−1302.8	−1302.8	4.48	−2684.5	0.230	−2.87	0.182	0.859	1.217
	0.6	0.68	−1117.5	−1117.5	4.60	−2533.8	0.242	−2.38	0.254	0.870	1.484
313.1	0.1	0.74	−217.9	−217.9	1.47	−678.1	0.043	−2.01	0.154	0.996	0.954
	0.2	0.68	−331.8	−331.6	2.16	−1009.4	0.073	−1.89	0.196	0.990	1.033
	0.3	0.64	−325.9	−325.9	2.47	−1100.8	0.088	−1.56	0.272	0.998	1.158
	0.4	0.75	−743.7	−743.7	3.59	−1869.9	0.156	−2.17	0.213	0.948	1.201
	0.5	0.73	−698.1	−698.1	4.28	−2041.1	0.212	−1.61	0.368	0.931	1.267
	0.6	0.72	−1116.6	−1116.6	4.58	−2551.4	0.240	−2.35	0.257	0.873	1.493

∗Critical micellar concentration.