Nanosized calcium carbonate particles were prepared with a semi-batch gas-liquid membrane contactor. A mathematical model of the semi-batch operated contactor was given, and the effects of Ca(OH)(2) concentration, CO2 partial pressure and additives on the absorption rate were estimated theoretically. The predicted data were consistent with the experimental results. The Ca(OH)(2) concentration and CO2 pressure have no apparent effects on the particles. In the presence of PVP and PEG, the particles are well-dispersed and the size is effectively reduced. After reaction, the membranes were washed with dilute hydrochloric acid and the membranes can be reused for at least 9 times without apparent performance deterioration. (C) 2011 Elsevier B.V. All rights reserved.