Nanosized calcium carbonate, strontium carbonate, aluminium hydroxide and alumina particles, about 50 nm in size, were prepared with a gas-liquid membrane contactor for the first time. The contactor provided large and constant interfacial area, as well as symmetrical supersaturation profile in the radial direction of the membrane fibers. Furthermore, all the gas could be absorbed in the non-disperse contacting mode, which was especially important for the expensive or hazardous gases. The effects of the reactant concentrations on the pH evolution and the particles morphology were studied. (c) 2009 Elsevier B.V. All rights reserved.