Freeze Drying of Aluminum Nanoflakes from Cyclohexane Suspensions

Hydrophobic aluminum nanoflake slurries were freeze dried using varying freezing conditions, aluminum concentrations, and shelf temperatures. The effectiveness of using cyclohexane as a carrier to produce dry, de-agglomerated aluminum powders was determined from light scattering measurements. Significantly less aggregation was observed in the dried aluminum powders when cyclohexane was used as opposed to water, with most aggregation being prevented by freeze drying dilute aluminum slurries at low shelf temperatures. A significant increase in the primary rate of freeze drying was also observed when particles were dried from cyclohexane compared to particles dried from water.