Kinetic theory of nonisothermal binary nucleation: the stage following thermal relaxation

A kinetic theory is constructed for a nonisothermal binary nucleation at the stage following the thermal relaxation of nuclei. The three-dimensional kinetic equation to be solved reaches beyond the framework of the Fokker–Planck approximation even if one of two components has a large value of condensation heat. It is shown that, by successively applying the method of Enskog–Chapman and the method of complete separation of variables to that kinetic equation, one can reduce the problem of constructing the three-dimensional kinetic theory to the well-investigated problem of solving an one-dimensional kinetic equation of first-order phase transition, in the nonstationary case as well as in the stationary one. For the steady state, the main characteristics of nucleation, including the nucleation rate, are found. Theoretical results are numerically evaluated for the nucleation in ethanol–hexanol system and compared with predictions of classical (isothermal) theory and experimental data.