Thermodynamics Research Center / ThermoML | Fluid Phase Equilibria

ABSTRACT

A capillary apparatus is presented for the measurement of liquid-liquid interfacial tension of two immiscible liquids, very easy to use with highly accurate results. The method benefits in essence having two concurrent capillarity actions united in one. The results of measurement over the range of 298 to 333 K for alkane + water, heptanol + water and hexanoic acid + water demonstrate that capillary rise method is a highly accurate method of liquid-liquid interfacial tension measurement, as known to be the case for liquid-vapor system. The coexisting capillarity actions involving liquid-liquid system is studied by the capillary constant, and importantly is practiced to be the augmentation of the two neat liquid capillary constants less a length scale proportional to the extent of effective dispersion interaction at the liquid-liquid interface.