Impurity driven clustering in a gas aggregation source

Gas phase Nan and Nan(NaOH)2 nanoparticles (n=50–250) are produced in a gas aggregation source. Heterogeneous Nan(NaOH)2 clusters are shown to be produced by accretion of sodium atoms on nucleation centers initially formed by a chemical reaction between H2O and Na or Na2 molecules. Mass distributions are compared for Nan grown on an homogeneous nucleation center and for Nan(NaOH)2 developing on an heterogeneous seed in the same condensation source, allowing the comparison between homogeneous and heterogeneous clustering efficiency.