Molecular Organized Assemblies Formed by Tetradecyl Aryl Sulfonate

Abstract

We investigated the micelles,reverse micelles,and microemulsions formed by three kinds of tetradecyl aryl sulfonates synthesized in our laboratory under different conditions using surface tension,iodine spectrometry,water solubilization,and phase diagram methods. The influences of molecular structure,solvents,inorganic saltss and short chain alcohols on these molecular organized assemblies were discussed. Results show that aqueous solutions or mixed polar solvents (EG-water) are unfavorable for micelle formation but that reverse micelle formation in non-polar solvents (n-heptane) is favorable when the branching coefficients of the lipophilic group in the tetradecyl aryl sulfonate molecules increase. A decrease in solvent polarity causes the surfactant solution to transform from a micellar solution to a monomer solution and then to a reverse micellar solution. Upon addition of inorganic salts or short chain alcohols,micelle formation is favored in aqueous solutions. Together with higher counter-ion valence states or alcohol alkyl carbon atoms,micelle formation increases even further. As the concentration of inorganic salt increases,the surfactant/ n-butanol/n-octane/NaCl/ water microemulsion systems transform from Winsor I to Winsor III and then to Winsor II at specific temperatures.