(169e) The Effect of Supersaturation on Supercritical Fluid Antisolvent Precipitation of Particles

Supercritical fluid antisolvent precipitation is a versatile approach to formation of small, and uniform, particles. The process involves dispersion of a solution into a supercritical fluid which is miscible with the solvent, but acts as an antisolvent to the solute resulting in precipitation of particles. The morphology of the particles produced depends, among other things, on the rate at which the solvent phase expands with the supercritical fluid, and the rate at which the solvent is dispersed in the supercritical fluid phase. In this work, the concentration gradient between the solvent and supercritical fluid phase is varied to investigate the effect of changing the rate at which the solvent phase is dispersed. Results are reported in relation to thermodynamic models for the antisolvent precipitation process. Several characteristic organic solvent/solute systems are investigated with CO2 as the supercritical antisolvent phase.