Ea is approximatively Gm the gibbs function of mixture . It is the difference between G of mixture and G of pur constituents of Mixture. It resumes all interactions ii and ij of constituents (i,j) of mixture. 

Thank you very much Dr. Besbes for you fruitful answer.

You could also use an Eyring’s absolute rate theory for liquid viscosity to find a free energy of mixing (G) of the binary system. Finding a dependence of the free energy of the binary mixture on the temperature at the different mole fractions of components you can calculate molar enthalpy and entropy of the system. The analysis of the thermodynamic values of the system will give you a good understanding of the interaction between molecules in your binary system. This approach was used in two attached articles, where the viscosity of binary mixtures is studied. We used a similar method for analysis of molecular interactions in binary monomolecular films (Amphotericin B and Cholesterol in Monolayers and Bilayers;  Interaction of Valinomycin and Stearic Acid in Monolayers). You could find these two articles in my Researchgate contributions.

There are a number of model theories based on approximations as adviced above. At present it is the best way to rely upon the molecular dynamics simulation approach. A numerical solution to the phenomenological definition of the shear viscosity in terms of the shear stress tensors that are associated with intermolecular interactions can be obtained. The temperature effect should be studied in order to computationally get the numerical solution to the viscosity coefficient just as in the case of experiment. Viscosity has the lon-ranged nature as in the case of hydrodynamics because of the integrations involved in the definition. Repulsive intermolecular interactions are also important as well as the attractive ones.  Someone who is unfamiliar  with the modern approach may be required to find a good collaborator in this field. Some others can find a good package for the computation.