Phase Behavior of Microemulsions Formulated with Sodium Alkyl Polypropylene Oxide Sulfate and a Cationic Hydrotrope

Abstract

The partial ternary phase diagram of anionic extended surfactant of alkyl polypropylene oxide sulfate C 12 (PO) 4 SO 4 alone and combined with the cationic hydrotrope, tetrabutyl ammonium bromide with water and decane were determined under ambient conditions. Middle phase microemulsion was formulated using salinity scans in the dilute region of surfactant/brine/decane. Visual inspection as well as cross polarizer and optical microscopy were used to detect anisotropy. Spinning drop tensiometer was used to measure interfacial tension (IFT). The first ternary phase diagram using the extended surfactant alone showed three one phase regions, the anisotropic lamellar liquid crystalline phase, L a and the isotropic L 1 micellar liquid and L 3 sponge phase. In the second ternary phase diagram using the extended surfactant combined with tetra butyl ammonium bromide, an isotropic micellar region, L 1 , appeared in the diluted area of the phase diagram. Meanwhile the L a phase disappeared completely and the three phase region has a bluish transparent middle phase. Interfacial tension measurements between middle phase and brine, and between decane and brine yielded ultra low values. Calculated IFT values using the characteristic length obtained using De Gennes approximation gave almost half the measured values. The interfacial rigidity was also calculated and compared to values obtained from the literature.

The magic of aqueous solutions of ionic liquids: ionic liquids as a powerful class of catanionic hydrotropes

“…There are few cationic hydrotropes known, 1 and only in the past few years some sparse studies using quaternary ammonium-based salts were reported. [70][71][72] In summary, the results obtained here clearly support that ILs may constitute a novel series of cationic hydrotropes. Effect of the cation alkyl side chain length 1) and all the compounds have a similar impact on the solubility irrespective of their alkyl side chain lengths.…”

Water-Diesel Microemulsions Stabilized by an Anionic Extended Surfactant and a Cationic Hydrotrope

“…[18] Earlier, we showed that the presence of the cationic hydrotrope, tetra butyl ammonium bromide (TBAB) had completely eliminated the formation of liquid crystal from the ternary phase diagram of C 12-13 PO 4 SO 4 Na, water and decane. [19] Therefore, in the present study we used TBAB in most of the work and compared it with another cationic hydrotrope, Variquat cc-9 NS which is a poly propylene oxide ammonium bromide.…”

Microemulsions as Emerging Electrolytes: The Correlation of Structure to Electrochemical Response

“…For instance, the γ interface at the oil/water interface without a surfactant is . Surfactants lower the γ interface significantly to for ionic surfactants and to for nonionic surfactants. − These values also correspond to the maximum mutual solubility between the oil and water phases. ,, Therefore, significant increases in the interfacial area occur to balance the low interfacial tension and control the formation of μEs. Underlying these changes in the interfacial area are changes in surfactant packing and any transport processes that are connected to it.…”