การเตรียมอนุภาคโดยใช้เทคนิคซูเปอร์คริติคัลฟลูอิด Particle Formation Using Supercritical Fluid Technique

Abstract

Supercritical fluid (SCF) is the substance at a temperature and pressureabove its critical point. The fluid exhibits intermediate behavior betweenthat of a liquid and a gas. In particular, SCFs possess liquid-like densities,gas-like viscosities and diffusities intermediate to that of a liquid and a gas.Carbon dioxide (CO2), the most widely used supercritical fluid, is cheap,chemically inert, non-toxic, and non-flammable. CO2 has an easilyaccessible critical point temperature of 31.1 oC and a critical pressure of 74bar, allowing the fluid to be used at mild conditions of temperatures (40 -60 oC). The supercritical fluid techniques for particle formation are classifiedbased on the roles of SCF including solvent, antisolvent, and solute. Therapid expansion of supercritical solution is a solvent-based process. Gasantisolvent recrystallization, supercritical antisolvent methods are theprocesses with SCF acting as an antisolvent and the particles from gassaturated solution is a solute-based process. The particles from supercriticaltechnique can be produced to meet certain morphologicalrequirements such as size, shape, and porosity by varying necessaryprocess parameters of the system.Key words: supercritical fluid, particle formation, solvent, antisolvent, solute