Interaction of Natural Dye (Allium cepa) with Ionic Surfactants

Table 2

Thermodynamic parameters for the interaction of dyes with surfactants at 25°C by conductivity method.

Surfactant	[Dye]; added; (g/L)	CMC; (mol dm^−3)	“β”; Degree of counter ion dissociation	−Δ𝐺^∘mic±0.05; (kJ mol^−1)	Δ𝑆^∘mic±0.10; (JK^−1 mol^−1)	Δ𝐻^∘mic±0.05; (kJ mol^−1)
CTAB; (0.02 g/L)	Nil	9.8 × 10^−4	0.75	27.5	90.76	−2.22
	0.1	9.3 × 10^−4	0.87	27.22	91.33	−0.56
	0.2	8.8 × 10^−4	0.90	27.33	91.71	−1.44
	0.3	7.7 × 10^−4	0.91	27.67	92.86	−1.09
NaLS; (0.20 g/L)	Nil	8.3 × 10^−3	0.66	21.79	73.14	−0.62
	0.1	7.7 × 10^−3	0.70	21.97	73.72	+1.03
	0.2	6.8 × 10^−3	0.80	22.25	74.67	−1.15
	0.3	6.3 × 10^−3	0.90	22.48	75.44	−0.07