Physicochemical Studies on the Interaction between Sodium Dodecyl Sulfate and Methylene Blue in Methanol-Water Mixed Solvent Media

Table 2

Surface properties of SDS in different volume fractions of methanol-water at 298.15 K.

Volume fraction of methanol	10^6 (mol·m^−2)		(Å^2 molecule^−1)		(mN·m^−1)				(kJ·mol^−1)
	a	b	a	b	a	b	a	b	a	b	a	b
0.1	2.06	1.85	80.68	89.86	19.1	21.2	0.28	0.25	−42.59	−45.77	2.03	2.18
0.2	1.57	1.40	105.92	118.5	13.5	16.75	0.21	0.19	−40.9	−44.74	1.66	1.84
0.3	1.01	0.77	166.31	215.45	7.5	10.2	0.14	0.11	−38.13	−44.65	0.85	0.86

a = calculated value in the absence of methylene blue. b = calculated value in the presence of methylene blue.