Synthesis of precipitated calcium carbonate nanoparticles using a two-membrane system

Precipitated calcium carbonate (PCC) nanoparticles were synthesized using a two-membrane system composed of a combination of a dialysis membrane tubing (DMT) and an emulsion liquid membrane (ELM). During the process, Ca²⁺ was diffused through the DMT, then the ELM, and finally reacted with CO₃^2– ions in the internal water-in-oil (w/o) emulsion droplets. Each individual droplet was used as a microreactor. Results showed that the particle size and morphology of PCC were depended not only on the diffusion rate of Ca²⁺ across the liquid membrane, but also the carrier concentration as well. The PCC particles were mainly in vaterite form and their size increased steadily with the reaction time, as proved by X-ray diffraction and transmission electron microscopy studies.From Kolloidnyi Zhurnal, Vol. 66, No. 6, 2004, pp. 829–834.Original English Text Copyright © 2004 by Zeshan Hu, Yulin Deng, Qunhui Sun.This article was submitted by the authors in English.