Hydrodynamic fragmentation of nanoparticle aggregates at orthokinetic coagulation

The aerodynamics of aero-dispersed nanoparticle aggregates is analogous to the hydrodynamics of lio-dispersed solid particles. Therefore the hydrodynamic fragmentation model may be used to partially interpret the stability of nanoparticle fluidization process. Our model indicates that, without continued doublet fragmentation of nano-aggregates, the fluidized nanoparticle suspension would be de-fluidized within minutes via the cascading aggregation. However, the experimental evidence of a sustained operation of fluidization of nanoparticle aggregates over a very long time period without changing the size of nanoparticle aggregates indicates that there is a dynamic balance between the aggregation and fragmentation of nano-aggregates in nanoparticle fluidization. The prediction of critical size of nanoparticle aggregates caused by fragmentation in stabilized fluidization agrees with our in situ measurements.