In order to realize continuously and rapidly prepare core-shell structured nanoparticles
a high-frequency impinging stream (HFIS) reactor is explored on the basis of the secondary rotation principle. In this reactor
not only the homogeneous nucleation and heterogeneous nucleation are coupled together
but the liquid-liquid multi-scale mixings are greatly intensified. And then
well-defined nano Fe3O4/MnOOH composites were fleetly obtained. The influences of four parameters on the macro and intrinsic kinetics of the coating process were investigated and discussed. Experimental results revealed that low coating ratio prolonged the induction period. Higher initial flux of the main stream intensified the initial dispersion
meso-mixing and micro-mixing. With the total flux of the branch streams being lowered
the initial dispersion was bad off. Furthermore
the computational fluid dynamics (CFD) simulations indicated that the inner layer of the S-shaped main stream had lower pressure and higher flow rate distributions. Therefore
the impinging points should be located in there. Two design defects of the reactor were found
and the corresponding improved schemes were proposed. Through continuous improvement
this reactor is promisingly used for the large-scaled
low-cost and high-quality production of various core-shell nanomaterials.