(328c) Size Classification of Nano and Submicron Particles in An Ultracentrifuge

Many nano-powders produced by wet or high temperature processes result in a relatively wide particle size distribution. The newly proposed classification method uses ultracentrifugal force for interfacial particle transport between two immiscible liquids. This process allows both batch and continuous multiple size fractionation of a particulate slurry. The effect of key parameters such as, type of liquids, use of dispersants, initial deagglomeration of particles by attrition milling, ultracentrifuge speed and run time, and the initial slurry concentration in the top liquid on separation efficiency will be presented for various powder systems. Current results show a separation at 40 nm for an initial slurry with a particle size distribution from ~25-100 nm. This method for the classification of nano-materials may result in a narrow particle size distribution that is frequently desired for many energetic and structural applications.