Fragmentation of Nanoparticle Agglomerates by Collisions in Supersonic Flows

We have developed a technology for the production of non-agglomerated nanoparticles by collisions of agglomerates in supersonic flows. To form non-agglomerated nanoparticles, we conducted the following three experiments: the collision of agglomerated particles in the supersonic flow with a fixed metal plate, the collision of agglomerates in the supersonic flow with a vibrating metal plate, and the counter-collision of two supersonic flows containing agglomerated particles. The probability of the fragmentation of agglomerates by means of the collisions was investigated by counting the number of non-agglomerated particles and agglomerated particles in TEM images. The results of the experiments revealed that the collision of agglomerates with a plate generates the problem of particles remaining on the metal plate even under low-collision velocity, and the counter-collision of two supersonic flows containing agglomerated particles induces the highly efficient fragmentation of agglomerates.