2017 Volume 54 Issue 7 Pages 432-436
Oscillatory zoning (OZ) is an example of internal composite patterns of materials. It has been reported that microparticles with OZ are obtained by a simple reaction-diffusion system. The two species of cations (Ba2+ and Sr2+) diffuse into a gel, while a reactive anion (SO42−) diffuses from the opposite side. After several days, OZ particles are prepared in a resultant precipitation band in the gel. Our goal is the clarification of detailed formation mechanism of such OZ particles and the control of the internal patterns of microparticles for practical applications. In this study, we examine the effect of ionic species on the resultant particles with various combinations of cations (Ba2+, Sr2+, Mg2+, and Ca2+) and anions (SO42− and CO32−). As a result, we found that OZ particles, core-shell (CS) particles, or particles with homogeneous composition are prepared depending on the combinations.
