The sorption capacity of ultrafiltration membranes and the potential field of the surface forces in solutions of milk proteins
The paper presents analysis of literature data to study the sorption capacity of the membranes and of the field potential of surface forces. Formulated the objectives based on the literature review, performed the selection of the studied ultrafiltration membranes UAM-150 UPM-100. The method of variable concentrations of experimental study of sorption activity of ultrafiltration membranes protein from cheese whey. The numerical values of equilibrium distribution coefficient of the protein in the membranes UAM-150 UPM-100, and solutions of milk whey in the range of protein concentrations from 9 to 32 g/l at temperatures from 293 to 308 K. based On the experimental data numerical values of empirical coefficients in the Freundlich equation for theoretical calculation of the equilibrium distribution coefficient. It is observed that the main factors influencing the sorption of substances by membranes from solution include the initial concentration in the solution and the temperature of the solution and analyzed the effect of temperature and concentration of the solution of milk protein on sorption capacity of ultrafiltration membranes UAM-150 UPM-100. In the case of increasing the temperature of the protein solution the sorption activity of membranes UAM-150 UPM-100 increased. The temperature increase reduces the viscosity and density of the solution and simultaneously increases its osmotic pressure. The decrease in the viscosity and density leads to increased permeability of the protein, increasing the concentration leads to saturation of the membranes with protein molecules, which further does not significantly increase the protein concentration in the membrane. The change in the concentration of solute at the membrane surface compared to its concentration in solution due to the influence of the field of surface forces. The calculated potential field of the surface forces of semi-permeable membranes UAM-150 UPM-100 and interpreted it change depending on the temperature and concentration of milk protein.