The synthesis of polycaprolactone (PCL) microspheres containing cerium (III) nitrate (Ce(NO3)3) self-healing agent via double emulsion evaporation method

Abstract

In this study, the synthesis of polycaprolactone (PCL) microspheres containing cerium (III) nitrate (Ce(NO3)3) as a self-healing agent was performed by water-in-oil-in-water (W1/O/W2) double emulsion evaporation (DEE) method. The parameters including stirring speeds (100, 200, 400, 600, 800, and 1000 rpm) and mixing temperatures (room temperature, 50 °C, 60 °C, and 70 °C) were investigated during the DEE formation. Based on the results, an increase in stirring speeds resulted in a decrease in an average particle size of the PCL microspheres containing Ce(NO3)3; yet it did not affect the average particle size of the PCL microspheres without Ce(NO3)3 inside. The suitable temperature for synthesizing PCL microspheres containing Ce(NO3)3 as well as PCL microspheres without Ce(NO3)3 inside should not exceed 50 °C during DEE formation because the PCL compound started to melt at temperature above 50 °C. Based on the results, the conditions of DEE formation at the stirring speed of 1000 rpm and mixing temperature of 50 °C yielded the PCL microspheres containing Ce(NO3)3 with an average size of 5.48 μm.