The corn starch micro-spheres were prepared in a W/O reverse emulsion via grafting and cross-linking polymerization in presence of cross-linker N,N-methylene bisacrylamide. The effect of ultrasonic treatment on the reverse emulsion and granularity of micro-spheres were investigated. A mechanism for ascorbic acid absorbed by the corn starch micro-sphere was studied by means of electrochemical method using ascorbic acid (AA) as model drug, and the paraffin-graphite power electrode modified by the starch micro-spheres as working electrode. The results showed that the diameter of micro-spheres was about 10～15 μm and these micro-spheres have a remarkable assimilation to ascorbic acid. This is mainly attributed to the inter-molecule hydrogen bond interaction.

corn starch micro-sphere; ultrasonic emulsification; cyclic voltammetry; hydrogen bond interaction