2001 journal article

Formation of perfluoropolyether coatings by the rapid expansion of supercritical solutions (RESS) process. Part 2: Numerical modeling

INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, 40(26), 6127–6139.

By: R. Franklin n, . Edwards n, Y. Chernyak n, R. Gould n, F. Henon n & R. Carbonell n

Source: Web Of Science
Added: August 6, 2018

The rapid expansion of supercritical solutions (RESS) process is a promising method for the production of ultrafine powders and aerosols of narrow size distribution for coatings and other applications. In this article, part 2 of a two-part study, the nucleation and subsequent growth of 2500 Mw perfluoropolyether diamide (PFD) from supercritical carbon dioxide (CO2) by expansion through a small-diameter nozzle is modeled in a three-stage, multidimensional fashion. The stages include a hydrodynamic solution, solvent−solute phase equilibria analyses, and an aerosol transport model. The hydrodynamics model successfully captures the vapor−liquid transition that occurs as carbon dioxide is expanded to ambient conditions. Cloud-point pressures and equilibrium compositions of the separated solvent−solute system are determined and are used in a multidimensional aerosol transport model. This model incorporates various mechanisms influencing droplet growth. Parametric studies are conducted to investigate the influen...