Vaterite production and particle size and shape control using seawater as an indirect carbonation solvent
Sehun Kim, Junhyeok Jeon, Myoung‐Jin Kim
Abstract
Vaterite, a type of calcium carbonate, has recently raised the potential for use as a drug delivery material and a filler for bone defects due to its high specific surface area and solubility, low specific gravity, and high porosity. However, existing methods of producing fine-particle vaterite exhibit limitations that annexed processes such as adding excessive additives or irradiating ultrasound are necessary, and mass production is impossible. We developed a simple, chemical additive-free, low-cost technology with mass production capability that can overcome problems faced in conventional vaterite production. We found that seawater is favorable for vaterite production and enables the reduction of its particle size because of its supersaturation in CaCO3, absence of magnesium, and high viscosity, and the reduced surface energy of vaterite. Using seawater as a solvent for indirect carbonation, we succeeded in producing a vaterite content of 100% containing fine particles without additives or additional processing. Spherical or elliptical vaterite was separately formed by adjusting the ionic strength of seawater. In addition, the ionic strength of seawater controlled the surface area and pore size of vaterite.