The sorption isotherms of oleic, linoleic, and linolenic acids from solutions in cyclohexane and heptane on magnetite

The adsorption-desorption isotherms of oleic, linoleic, and linolenic acids from solutions in cyclohexane and heptane on the surface of magnetite were obtained by the equilibrium adsorption method. The adsorption of fatty acids was described in terms of the theory of volume filling of micropores. This theory was used to calculate the limiting adsorption values, characteristic energy, and volume of the pore space. In solutions in cyclohexane, the adsorption-desorption isotherm of oleic acid was situated above the isotherms of linoleic and linolenic acids. The situation was opposite with adsorption from heptane. The conclusion was drawn that the limiting adsorption and characteristic energy values increased from linolenic to oleic acid in adsorption from cyclohexane and decreased from linolenic to oleic acid in adsorption from heptane. The adsorption-desorption isotherms exhibited hystereses. Original Russian Text ? V.V. Korolev, O.V. Balmasova, A.G. Ramazanova, 2009, published in Zhurnal Fizicheskoi Khimii, 2009, Vol. 83, No. 6, pp. 1156–1160.