Preparation of narrow-dispersed electronic ink microcapsules

Electronic ink microcapsules in narrow dispersity were prepared by complex coacervation using gelatin and gum Arabic as wall materials. The effect of various parameters, such as sodium dodecyl sulphate (SDS) and agitation rate, was investigated. From experiment, the average diameter and dispersity of core droplets decrease as the concentration of SDS and agitation rate increase. And the relationship between average diameter and agitation rate is linear in log-log scale. The optimal reaction conditions of the synthesis of microcapsules were 0.01 wt% of SDS and 800 r/min of agitation. The capsules prepared by the optimized process are even and regular and their surfaces are smooth. The diameter of the capsules and the thickness of the shell wall were about 40 and 2 microns, respectively.