Thermodynamic and kinetic study of spinodal phase separation in heptane–phenol system

• We calculated the phase diagram of heptane–phenol binary system.
• Phase separation patterns under different conditions were simulated.
• The speed of phase separation is affected by the quench temperatures.
• The resultant morphology is determined by the initial average concentration.

The Flory–Huggins theory and phase-field method were used for thermodynamic optimization and kinetic simulation of spinodal phase separation in heptane–phenol binary system in this paper, respectively. The interaction parameter χ12χ12 was optimized, and the calculated phase diagram was in good agreement with experimental data. The kinetic simulations indicated that the speed of spinodal phase separation is significantly affected by the quench temperature and the resultant morphology is determined by the initial average concentration. The results obtained could shed light on investigating phase separation patterns in immiscible organic systems.

Graphical AbstractThe Flory–Huggins theory and phase-field method were used for thermodynamic optimization and kinetic simulation of spinodal phase separation in heptane–phenol binary system in this paper, respectively. The interaction parameter χ12χ12 was optimized, and the calculated phase diagram was in good agreement with experimental data. The kinetic simulated results indicated that the speed of spinodal phase separation is significant affected by the quench temperature and the resultant morphology is determined by the initial average concentration Calculated phase diagram of heptane–phenol binary system Phase separation patterns at different quench temperatures in heptane–phenol system. (a) time steps t=50; (b) final stage The phase separation patterns with different initial average concentrations at 280 K in heptane–phenol system during time steps 50 and 100Figure optionsDownload as PowerPoint slide