Surfactant-Mediated Transport Through Liquid Hydrocarbon Membranes

Abstract

Water flux through layers of hexadecane and isopropyl myristate has been measured in the presence of non-ionic surfactants. In the absence of surfactant the diffusion coefficient for water through a layer of hexadecane is 4.10 x 10⁻⁵ cm²s⁻¹ and a permeability coefficient of 8.29 x 10⁻⁹ cm s⁻¹ through a 0.267 cm layer of hexadecane was calculated. Water flux and the permeability coefficient of layers of hexadecane and isopropyl myristate increased on addition of sorbitan mono-oleate (Span 80). The effect of a combination of hydrophilic and lipophilic surfactants in the oil layers on water flux has been studied. At a constant Span 80 concentration, increasing concentration of either sorbitan poly-(oxyethylene) oleate (Tween 80) or sorbitan poly-(oxyethylene) tri-oleate (Tween 85) increased water flux.