A STUDY OF MANUFACTURING MICRO-NANO PARTICLES OF GREEN TEA BY RAPID EXPANSION OF SUPERCRITICAL SOLUTIONS METHOD

摘要

One of the most important areas of research in the material science field is the manufacture of fine particles. Small particles have an improved dissolution rate and are therefore more easily absorbed into biological in-vivo tissue or the skin surface layer. This study investigates the effects of temperature and pressure on the particle size of green tea powder manufactured via the rapid expansion supercritical solution method. The dissolution rate of the green tea extract in the supercritical carbon dioxide solution is enhanced via the addition of a modest quantity of ethyl alcohol. The size of the particles produced under different temperature and pressure conditions is analyzed using a laser particle size analyzer. The results show that under constant temperature conditions, a higher pressure causes the particle size decreased. Meanwhile, for a constant pressure, both the particle size and the volume of powder produced reduce as the temperature is increased. Overall, the results show that a minimum particle size of 58 nm is obtained at a pressure of 2000 psi and a temperature of 45°C.