Abstract
This manuscript reports the partitioning of benzothiophene (BNP), a bioactive organic compound, between the aqueous phase and micellar media of an anionic surfactant, sodium dodecyl sulphate (SDS) and a cationic surfactant, cetyl trimethyl ammonium bromide (CTAB). Simple and differential UV/visible spectroscopic studies of said systems have been conducted in premicellar and post-micellar concentration ranges. The experimental results reveal that in the premicellar region, the molecules of BNP get attached with monomeric surfactant molecules, while in the post-micellar region; they are accommodated within the micelle. The bathochromic shift is observed in the UV/visible spectra of BNP in the presence of both surfactants. The water/micelle partition coefficient (
K
x
) and binding constant (
K
b
) were calculated using differential absorption data and subsequently the values of free energy of partition (∆
G
p
) and free energy of binding (∆
G
b
) were calculated. The values of
K
x
show that the solubilization of BNP is more spontaneous and takes place to a greater extent in micellar media of SDS than in CTAB.