INVESTIGATION OF THE NUCLEATION AND GROWTH OF METHANOL CLUSTERS FROM SUPERSATURATED VAPOR BY MOLECULAR DYNAMICS SIMULATIONS

Vapor-liquid nucleation and growth kinetics of methanol clusters were investigated by molecular dynamics simulations. Supersaturated states were generated by temperature quenches of a stable gas phase. The initial methanol vapor phase density varied from 0.056 to 0.446 mol/dm(3), the target temperature after the quench ranged from 250 K to 290 K. The complete system consisted of methanol and argon, which is a carrier gas removing the latent heat of condensation from the system. The growth of the largest cluster in the system, the average cluster size, and the initial cluster size distributions were analyzed. The results were compared to calculations with the classical nucleation theory (CNT) using macroscopic properties obtained from simulations with the same molecular model. The rates calculated with the CNT and the simulation data at high supersaturation differed by two to three orders of magnitude. Simulation results and experimental data taken from the literature were consistently below the CNT values.