(82d) Characterizing Nanoparticle Agglomerates in a Nanopowder Fluidized Bed
Here, we study different ceramic oxide nanoparticles. In our lab, we use such particles to functionalize them via atomic layer deposition in a fluidized bed, e.g. for catalysis. In order to optimize this process, it is important to know the structure of the agglomerates. We describe the structural characteristics of each hierarchical level of complex agglomerate formation obtained from two in situ techniques: small-angle neutron scattering for the smaller scales, and a settling tube coupled with a boroscope for the larger scales. The first scale, namely aggregates, are open structures with a fractal dimension of about 1.5, which then form simple agglomerates with a fractal dimension close to 3, that later cluster into complex agglomerates that present a fractal dimension of about 2. In addition, we characterize the contact mechanics of the nanopowders agglomerates using atomic force microscopy. Finally, we will discuss the entrainment of nanosized clusters from the fluidized bed.