Fusion of the Extended Modified Liquid Drop Model for Nucleation and Dynamical Nucleation Theory

We present a new phenomenological approach to nucleation, based on the combination of the “extended modified liquid drop” model and dynamical nucleation theory. The new model proposes a new cluster definition, which properly includes the effect of fluctuations, and it is consistent both thermodynamically and kinetically. The model is able to predict successfully the free energy of formation of the critical nucleus, using only macroscopic thermodynamic properties. It also accounts for the spinodal and provides excellent agreement with the result of recent simulations.

Figure 1

$P\mathrm{\text{−}}V$ isotherms for LJ argon at $T=85\mathrm{K}$ and different values of $N$. The values of the surface tension, liquid density, and equilibrium vapor pressure are the same as in Ref. 9.

Figure 2

Free energy of formation of the critical cluster as a function of the saturation ratio for argon at $T=85\mathrm{K}$ using the EMLD-DNT model Eq. (6) (solid line) and CNT (dashed line).

Figure 3

Free energy of formation of the critical cluster as a function of $1/\Delta {\mu }^2$ for a truncated and shifted LJ fluid ($R_c=2.5$) at reduced temperature $T=0.741$ using the EMLD-DNT model Eq. (6) (with the LJ equation of state) (solid line) and CNT (dashed line). The circles are the data from the simulation of Ref. 7.

Figure 4

Number of molecules in the critical cluster $\Delta n^{*}$ as a function of $1/\Delta {\mu }^3$, for a LJ fluid at $T=0.741$, as predicted by the EMLD-DNT (solid line) and the CNT (dashed line), compared to the simulation results of Ref. 7 (open circles). The total number of molecules $N^{*}$ confined in the volume $V_m$ in the EMLD-DNT cluster and $n_d$ (see the text) are also plotted.