(544j) Classification of Nanopowders in An Ultracentrifuge

In many energetic and structural applications a narrow particle size distribution is frequently desired to control specific properties such as ignition delay and propagation velocity of the combustion front. However, up to now most size classification techniques available require that the material be in an aerosol form. These classification methods have very low throughputs. Our newly developed size classification technique for nanopowders is based on interfacial particle transport between two immiscible liquids using ultracentrifugal forces. This wet classification process allows for both batch and continuous flow size fractionation of a slurry consisting of nanopowders. The key parameters that effect the separation efficiency are: type of liquids, use of dispersants in the initial slurry, initial deagglomeration of the particles, ultracentrifuge speed and run time, and the initial particle loading of the slurry. The up to date results show that the use of the two liquid classification system allows for the classification of the nano-materials based on their particle size. This classification system will also be modeled using computational fluid dynamic FLUENT software. The modeling of this system will allow for the prediction of the centrifuge speed and run time that will be needed for the desired fractionation of the initial slurry. The classification results for different nano-material systems will be presented.