Calculation of non ideal terms

In addition to relaxation and electrophoretic forces (fig. 5.1), which are corrections to the main driving forces, the diffusion must be taken into account. Indeed, acoustic wave induces concentration gradients and then, diffusion effect appears. This effect will be taken into account after the calculation of ralaxation and hydro-dynamic corrections. MSA is again used to describe the equilibrium state. 

The main driving force to be included in the calculation of the relaxation effect is the electric force. Following Onsager s formalism [2], and assuming that the nonequilibrium time-dependent two particle correlation function is of the form 

Lastly, /iji is replaced by its MSA expression [70, 26, 27], which leads after some algebra, and expanding the results in a first-order power series of / Ci (typically of the order of 10 ), to the relaxation correction force 

Using eq.(5.68), it follows that the potential amplitude is given by 

97) contains three imknowns the closest-approach distance tr, the mass of the solvated anion, and that of the solvated cation. 

---