Taiji Nishi

Preparation Characteristics of Monodispersed Water-in-Oil Microspheres by a Polymer Microchannel

In this study, a low cost polymer microchannel (MC) plate with high resistance to alkali was used to produce monodispersed microsphere (MS). The effects of pressure and concentration of surfactant on the average diameter and coefficient of variation (CV) of MS produced by the polymer MC were investigated. The results indicated that when tetraglycerin condensed ricinoleic acid ester (CR-310) was used as surfactant, monodispersed (CV, about 5%) water-in-oil microspheres (W/O-MS) ranging from 40-60 µm in average diameter were produced successfully using a polymer MC with the dimension: width 20 µm, depth 10 µm, length 120 µm, and terrace length 30 µm. The optimum pressure zone to produce MS was 0.4-1.0 kPa. It was also found that the concentration of surfactant had little effect on average diameter and CV of MS in polymer MC emulsification process. A silicon MC plate with similar dimension to the polymer MC was tested for comparison, and little significant difference was observed in the average diameter and CV of MS.