Comparative study of the synthesis of silica nanoparticles in micromixer-microreactor and batch reactor systems

Two different reactors, namely a microreactor with an interdigital micromixer and a batch reactor, have been used to prepare silica nanoparticles. The effect of synthesis variables was studied, and the results are compared in terms of particle-size distribution and synthesis reproducibility for different reaction conditions. The microreactors operated with shorter nucleation times and a greater homogeneity in terms of temperature and composition. This resulted in narrower particle-size distributions and a lower polydispersity. The synthesis reproducibility and the reactant (TEOS) conversion were also higher when using micromixers compared with batch reactors for the same synthesis times. Because of these characteristics micromixer-microreactor systems appear as a promising alternative for the continuous synthesis of nanoparticles. (C) 2011 Elsevier B.V. All rights reserved.