Additives as CP modifiers in an anionic micellar solution

Here we report observance of clouding phenomenon in aqueous anionic surfactant tetra-n-butylammonium dodecyl sulphate (TBADS) in presence of different inorganic and organic compounds. Inorganic salts increase the CP followed by a decrease with the continuous addition of salt. The addition of aliphatic organic compounds causes both increase and decrease in CP depending upon their solubility (in water) and hydrophilic ranking. The additives of urea family also influence CP both ways depending on whether they are containing >CO or >CS moiety. The former mainly affects water structure while the latter can interact directly with the micelle. In doing so, thio compounds may compete with tetra-n-butylammonium counterion (TBA+) for the space near the micellar surface. All sugars decrease the CP, which is in cognizance to their effect on the critical micellar concentration of surfactants. Influence of amino acids on the CP is dictated by their acidic/basic nature. The over all effect of the additives is found to depend upon their ability to modify micellar morphology and/or structure of water.