Preparation and Size Control of Starch Microgels by the Heat Treatment of their Coacervates

Abstract

Concentrated aqueous solutions of starch and poly( ethylene oxide) were prepared at 80 °C, and they were mixed to form simple coacervates of starch through the phase separation. This suspension was immediately cooled in an ice-containing water bath to get spherical starch microgels. The average diameter was measured to be 35 pm by particle size analyzer. The average diameter was revealed to increase with incubation time as coacervates before cooling. For example, starch microgels with average diameter of 180 pm were obtained by the cooling of the coacervates incubated at 80 °C, for 10 min.