Concentration dependence of mutual diffusion coefficients in regular binary solutions: a new predictive equation

1985 ◽  
Vol 24 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Francis A. L. Dullien ◽  
Abdul Fattah A. Asfour
2006 ◽  
Vol 258-260 ◽  
pp. 305-309 ◽  
Author(s):  
Ana C.F. Ribeiro ◽  
Cecilia Isabel A.V Santos ◽  
Victor M.M. Lobo ◽  
Artur J.M. Valente ◽  
Pedro M.R.A. Prazeres ◽  
...  

Binary mutual diffusion coefficients have been measured for aqueous solutions of some carbohydrates (glucose, fructose, lactose, sucrose, α-cyclodextrin and β- cyclodextrin) at concentrations from 0.002 mol dm-3 to 0.010 mol dm-3. The concentration dependence of the diffusion coefficients at physiological temperature, 37 °C, is discussed on the basis of their structures.


Author(s):  
V. Nikonova ◽  
V. Obukhovsky

In the article within the complex-associative model of liquid systems the nonlinear diffusion for a number of binary solutions, such as acetone-chloroform, tetrachlorethane-chloroform, diethyl ether-chloroform and benzene-chloroform, is considered: Real binary solutions are replaced by ideal three-component ones, which consist of averaged two associates of substance and solvent and an effective averaged complex, which is the result of quasi-chemical reactions of molecular solutions. The coefficient of mutual diffusion, which nonmonotonically depends on the concentration of the solvent, is represented as a matrix of partial coefficients of mutual diffusion, which are constant values and represent the material parameters of the considered solutions. The method of analytical calculation of numerical values of such quantities when considering the simplest type of one averaged complex is developed. It is shown that the partial coefficients are constant values and the analysis of their values for the considered solutions depending on the structure of the molecules of the substance, enthalpy and temperature is carried out. Based on the proposed approach, the deviation of the calculated «Fick’s» coefficient of mutual diffusion through the matrix of partial coefficients in comparison with experimental data is less than 2.5%.


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