Measurement of Interface Tension of Phosphoric Acid In Emulsion Liquid Membrane System by Visualization

Abstract: Interface tension is a concept of macrography world. In submicroscopic space, is the concept of interface tension exist? In my experiment, combined with infrared spectroscopy and visualization technology, the interfacial tension could be easily got in perspective of submicroscopic.

During this experiment, dodecyl benzene sulfonic acid as the interface activator was respectively dissolved in kerosene, ethanol, n-butanol and n-octanol, and made into specimens of different concentrations. Then using a capillary to take these specimens into the wet-process phosphoric acid. By self-designed visualization device, the mass transfer of dodecyl benzene sulfonic acid magnesium (calcium) was observed. After the mass transfer was finished, Then curvature radius of gas-liquid interface was measured by image analysis software and visualization device. Finally obtained interface tension in liquid-liquid phase and the cmc(critical micelle concentration) of dodecyl benzene sulfonic acid magnesium in different solvent. The cmc of dodecyl benzene sulfonic acid magnesium was 0.0024mol/L in kerosene and the other was 0.0179mol/L, 0.0043mol/L and 0.0119mol/L in ethanol, n-butanol and n-octanol. Those interfacial tensions were 0.0105N/m, 0.0334N/m, 0.0231N/m, and 0.0306N/m respectively in those solvents.