Liquid Crystals in Aqueous Solutions of Sodium Naphthenates

Phase Behavior of Sodium Naphthenates, Toluene, and Water

“…Close similarity between the solubilization of toluene by SN and the solubilization of different hydrophobic compounds by hydrotropes (9) suggests that the multicomponent SN is in effect a hydrotrope. The shape of the single-phase range L1 (Fig.…”

“…Thus, no effort was made to determine the composition of the equilibrium phases. The properties of the phase diagrams with pseudo components were discussed in our previous paper (9). The appearance of two types of gel phases (Fig.…”

“…The choice of sodium naphthenates for phase diagram studies is also supported by the fact that the lamellar liquid crystal (LLC) phase has been identified in water/sodium naphthenate systems (9). This would imply the possibility of LLC stabilization of O/W or W/O emulsions.…”

“…However, crude oils, especially heavy oils and bitumen, contain substantial quantities of natural surfactants, mostly derivatives of naphthenic acids, which are capable of self-assembly into organized phases (9). According to our best knowledge, crude oils or bitumen has never been a target of phase diagram investigations.…”

The Hydrotrope Action of Sodium Xylenesulfonate on the Solubility of Lecithin

“…Third, the hydrotrope action of SXS on hydrophobic materials is strongly dependent on the chemical structure of these materials. For example, SXS enhances the solubility of nitrobenzene in water 50-fold (50) but SXS is not able to increase the solubility of toluene in water (51). On the basis of the first and second pieces of information, one can still interpret the increased solubility of lecithin along the lines of some kind of non specific mechanism (for example, salting-in effect); the third piece of information makes it probable that the increased solubility is related to a specific interaction between the SXS and lecithin.…”