Particle morphology, habit, and size control of CaCO3 using reverse microemulsion technique

The particle morphology, habit and size of calcium carbonate were controlled simultaneously via reverse microemulsion technique. Several important operating variables in AOT/isooctane/water reverse microemulsion system, such as a) values (water/surfactant molar ratio), S values (water/oil molar ratio), R values (molar ratio of CaCl2 to Na2CO3) and type and concentration of additives, were systematically investigated. Among which, the R value is the most important factor affecting particle habit and polymorph of calcium carbonate. On the other hand, the addition of additive strongly influences the particle morphology, size and habit of calcium carbonate. As a result nano-sized spherule and micro-sized hexagonal-plate, disk. doughnut and spindle particles of calcium carbonate were successfully synthesized in this study. These products with distinctive morphology, size, and habit are expected to be applicable in various industrial fields. (c) 2008 Elsevier Ltd. All rights reserved.