Solubility Enhancement of Polycyclic Aromatic Hydrocarbons (PAHs) Using Synergistically Interacting Gemini-Conventional Surfactant Systems

The aqueous solubility of otherwise slightly soluble organic substances can be enhanced by the incorporation of surfactant micelles. In this research, the water solubility enhancements of polycyclic aromatic hydrocarbons (PAHs) viz. naphthalene, anthracene and pyrene, by micellar solutions at 30 ºC using gemini-conventional (ionic and nonionic) surfactants in their single and binary systems have been measured and compared. The solubilization capabilities of gemini surfactant butanediyl-1,4-bis(dimethylcetylammonium bromide) (G4) with cationic cetyltrimethylammonium bromide (CTAB), anionic sodium bis(2-ethylhexyl)sulfosuccinate (AOT) and nonioinic polyoxyethylene (20) cetyl ether (Brij 58) have been quantified in terms of molar solubilization ratio (MSR), partition coefficient ( K m ) and free energy of solubilization (Δ G s 0 ) of the PAHs. The order of solubilizing power of pure surfactants is Brij 58 > G4 > CTAB > AOT and in binary systems G4-Brij 58 > G4-CTAB > G4-AOT.