Synthesis of nanophase silver particles using an aerosol reactor

In this work, nanophase silver (Ag) particles were produced by an evaporation/condensation aerosol process in a jet flow reactor, and collected via electrostatic precipitation. Silver nitrate (AgNO3) was used as the precursor and the aqueous AgNO3 solution was delivered into the reactor by liquid atomization. From transmission electron microscopy, the mean particle diameter was determined to range from 16 to 53 nm at different experimental conditions that were studied, and the formation of rounded and unagglomerated particles was evident. Currently, the effects of mixing rate and precursor concentration on the characteristics of the resulting Ag particles were examined. The mean particle size was also estimated from the measurements of the particle number concentration entering the collection device. Collection efficiency above 90% using an electrostatic precipitator was attributed to a sufficiently high particle charging efficiency. Particles collected by filtration rather than electrostatic precipitation formed agglomerates, suggesting that electrical charging greatly reduced the coagulation rate. (C) 2002 Elsevier Science Ltd. All rights reserved.