Introduction
Supercritical Fluid Extraction can be used to generate a finely controlled stream of micro particles. The desired substrate is solubilised in the supercritical fluid and transported to an orifice where the sudden expansion of carbon dioxide creates a stream of nano-micro particles. Control of orifice shape, temperature and pressure differential are used for definition of particle size and morphology.
Features
- Unimodal particle size distributions with the pulsation free pump.
- Creation of fine particles without thermal and chemical degradations.
- Contamination free recirculation of supercritical solvent.
- Diamond orifices with diameters from 15 to 300 microns.
Measures
Particles are created either by the RESS (Rapid Expansion of Supercritical Solutions) or GAS (Gas Anti-Solvent Recrystallization). Examples of RESS include bioerodible polymeric microspheres loaded with a therapeutic drug; chemical phase change ie PVDF α to β form. Examples of GAS include Creation of fine powder explosives such as RDX cyclotrimethylenetrinitramine ; crystallization of aspirin; production of colour pigments.