PGSS, microencapsulation and other processes
Elaboration of split solids with supercritical fluids

A gas under pressure can be solubilized in a liquid in large quantities: this is the property used here. A dense gas, most commonly CO₂, is dissolved in a liquid in a first autoclave. This liquid can be a solution, a suspension or even a polymer melt.

The resulting gas-saturated solution is sent through a nozzle into an expansion chamber (figure 6). Particle generation takes place during depressurization, and the particles formed are then collected in the expansion autoclave. During depressurization, CO₂ can also act as an aerosolization activator.

This process was initially developed for polymers in which large quantities of CO₂ can be dissolved. This dissolution...