Solubilization of Phenanthrene and Fluorene in Equimolar Binary Mixtures of Gemini/Conventional Surfactants

This study deals with the enhanced solubilization of polycyclic aromatic hydrocarbons (PAHs) such as phenanthrene (PHE) and fluorene (FLR) in a pure cationic gemini (G6) and three conventional surfactants polyethylene glycol dodecyl ether (Brij35), cetyltrimethyl ammonium bromide (CTAB) and sodium lauryl sulfate (SDS)] as well as in their equimolar binary combinations (G6-Brij35, G6-CTAB and G6-SDS). Their solubilization efficiency toward PHE and FLR has been quantified in terms of the molar solubilization ratio (MSR) and themicelle-water partition coefficient (K_m). The ideality/nonideality of the mixed micelles is discussed with the help of Clint, Rubingh and Rosen's approaches. These theories determine the deviation of experimental critical micelle concentration (CMC) values fromideal criticalmicelle concentration, whichwas measured by evaluating the interaction parameters (β^m and β^σ). Negative values of β^m were observed in all the equimolar binary systems, which show synergismin the mixedmicelles.Whereas at air/liquid interface synergismwas observed in the systems G6-CTAB and G6-Brij35; G6-SDS exhibited an antagonistic effect. The order of MSR and K_m was G6-CTAB N G6-Brij35 N G6-SDS for phenanthrene as well as for fluorene.