Temperature dependence of droplet nucleation in a Yukawa fluid

We have studied the temperature dependence of gas-to-liquid nucleation in Yukawa fluids with gradient theory and density functional theory. Each of these nonclassical theories exhibits a weaker (i.e., better) temperature dependence than classical nucleation theory. At fixed temperature, the reversible work to form a critical nucleus found from gradient theory approaches the value given by density functional theory as the supersaturation increases. At high temperatures, the two theories remain quite close over a wide range of vapor densities. As the temperature is reduced, the difference between the two theories increases with decreasing vapor density. Compared to the classical theory we find that gradient theory can improve the predicted temperature dependence of the nucleation rate, although not always to the same degree as density functional theory. Finally, our results show that the scaling behavior of density functional theory proposed by McGraw and Laaksonen can be extended to higher temperatures if the incompressibility assumption is avoided when evaluating the classical reversible work. (C) 2003 American Institute of Physics.