Applying Gradient theory to calculate nucleation rates and compare with data.

1. Applying Gradient theory to calculate nucleation rates and compare with data. Nora Al-Zubi Dr. Abdalla Obeidat Department of Physics JUST

2. Outline • Metastability and nucleation • Temperature dependence of classical theories • DFT and the road to GT (why GT?) • Applications to GT • Conclusions

3. Metastable and unstable regions for the van der Waals fluid fluid critical point liquid gas spinodal binodal • The binodal curve (solid dome)separates one-phase and two-phase states • TC = criticaltemperature • The spinodal curve (dashed dome) separates metastable and unstable states • One true horizontal isotherm is shown • Adapted from Davis (1996)

4. Classical nucleation rates are too low at low T; too high at high T.

5. Chain of Rotators Equation of state for Ethanol and Methanol

6. DFT and the road to GT

7. Density Gradient theory

8. The ingredients for GT

9. DFT Adv. Statistical Mechanical approach disAdv. Depends on intermolecular potential GT disAdv. Approximation to DFT Adv. Semi form of DFT Depends on EOS GT Why?

10. Applications to GT using JA and CPHB • Density profiles • Thicknesses • Number of molecules • Radius of droplets • Work formation • Nucleation rates

11. Density Profiles

12. Nucleation rates of H2O based on CPHB

13. Conclusions • Gradient theory is promising theory to improve the temperature dependence of nucleation rates.

14. Thank You