Investigation of Vapor‐Liquid Nucleation for Associating Fluids by Density Gradient Theory

Abstract

An equation of state (EOS) applicable to both the uniform and non-uniform associating fluids was established by using the density-gradient expansion, in which the influence parameter κ is formulated as a function of temperature. The molecular parameters were regressed by fitting to the experimental data of vapor pressures and liquid densities. Within the framework of density gradient theory (DGT), the nucleation rates for water, heavy water, methanol, ethanol, 1-propanol, 1-butanol, 1-pentanol and 1-hexanol were calculated. The results were satisfactory compared with the experimental data. Our study shows that DGT preserves all the advantages of density functional theory (DFT) in capturing the structure and properties of nucleus but gives much more accurate nucleation rates by adjusting the influence parameter.

Bulk and Interfacial Properties for CO2‐SO2 Binary Mixtures

“…[11][12][13][22][23][24][25][26][27][28][29][30][31][32][33] The expansion is expressed as: κ κ is the cross-influence parameter. Keeping the lowest order term in the expansion, the Helmholtz free energy can be expressed as:…”

Study on Vapor‐Liquid Nucleation Rates for n‐Alcohols by Density Functional Theory

“…DFT is theoretically better than DGT because in the calculations of interfacial properties and nucleation properties, DFT only needs the molecular parameters regressed from bulk properties as input. However, in the calculation of DGT, for the determination of both surface tension [53][54][55] and nucleation rates, 42 additional influence parameters are need.…”

“…Recently, Fu and Liu 42 used a density gradient theory (DGT) to correlate the nucleation rates for n-alcohols (n from 1 to 6) and their results showed that DGT preserves all the advantages of DFT in capturing the structure and properties of nucleus but gives much more accurate nucleation rates by adjusting the influence parameter. However, in the work of Fu and Liu, 42 the influence parameters were regressed by fitting to the experimental data of nucleation rates, hence their model has a lack of predictive function.…”