Solubilization of Polycyclic Aromatic Compounds into n-Decyltrimethylammonium Perfluorocarboxylate Micelles

Characterization of Pyrene Solubilization in Selective Micellar Media of Novel Bio-degradable Natural Surfactant Saponin (Extracted from Soap Nut) and Conventional Surfactant SDBS in Presence and Absence of Common Salt NaCl

Solubilisation of pyrene (PAHs) in aqueous micellar solutions of natural surfactant saponin and conventional surfactant sodium dodecylbenzene sulfonate (SDBS) has been examined by UV-Vis and steady state fluorescence spectrometry at 30°C. The effect of addition of common salt NaCl on the I1/I3 of fluorescence has also been determined. The experiment concludes that the pyrene molecules were incorporated in the palisade layers of both micelles because of their hydrophobic character. The interaction of pyrene with a neutral saponin micelle resulted in a red shift of UV absorption spectra, while the negative headed surfactant SDBS showed no such phenomena. The resulting thermodynamic parameters proved the better efficiency of the bio-surfactant saponin for the solubilization of pyrene with respect to that of the conventional surfactant SDBS. With increasing ionic strength (on addition of NaCl) the solubilization of pyrene was found to be better and effective in both the surfactant mediums.

Solubilization of pyrene in aqueous micellar solutions of gemini surfactants C12-s-C12⋅2Br

Solubilization of pyrene in aqueous micellar solutions of quaternary ammonium gemini surfactants C(12)-s-C(12).2Br has been examined by UV spectra and steady fluorescence spectra at 30 degrees C. The results showed that pyrene molecules were incorporated in the palisade layers of the micelles and interacted with the quarterary ammonium head groups through cation-pi interaction, resulting in red shift of the UV absorption spectrum. C(12)-s-C(12)2Br (s=3,4,6) micelles have stronger ability for solubilization of pyrene than conventional surfactant C(12)TABr micelles. With increasing spacer length of C(12)-s-C(12).2Br, the micelles become more adaptable to solubilizing pyrene, which even forms the dimers as in the case of s=3,4,6, while pyrene solubilizes in the micelles (s=2) mainly in single-molecule form due to the more compact structure of the micelle in comparison with that at s>2.