Manufacturing Polymer Nano Particles by Using Supercritical Fluids

The aerosol solvent extraction system (ASES), which is one of the supercritical anti-solvent system (SAS), has been studied to produce nano-particles of polymers such as poly(l-lactic acid) (PLLA) and polystyrene (PS), etc. Dichloromethane (DCM, CH2Cl2) and supercritical carbon dioxide were adopted as a solvent and as an anti-solvent material, respectively. The effect of the process parameters such as temperature, pressure and solution concentration ,etc., on particle size has been investigated. The morphology and size of the particles re-crystallized by ASES process were observed by using a scanning electron microscope (SEM) image. The mean particle size and its distribution of processed particles were measured by using a laser diffraction particle size analyzer (PSA). The particle size increased with increasing temperature and pressure. Also, higher solution concentration led to lager particle size and broader particle size distribution