Direct Synthesis of Al, Mg, Ni, and Ti Nanoparticles by Induction Flow Levitation Technique

Nanoparticles of Al, Mg, Ni, and Ti with an average size less than 50 nm were obtained directly from bulk samples by the inductive flow levitation (IFL) technique. The main advantages of this method are high productivity (up to 200 g/h of nanoparticles), control over the size of nanoparticles in a wide granulometric range (0.5–500 nm), and noncontact heating (up to 2500 °C), which determines the purity of the product and the compliance of the method with the basic principles of “green chemistry” (direct synthesis). The IFL method belongs to gas-phase technologies, a distinctive feature of which is metal evaporation in a suspended state (induction levitation) and noncontact heating. For the levitation of volumetric samples, seven types of induction coils were developed in the work in which the “temperature-levitation” properties were investigated. On the inductor of the fifth type, the modes of obtaining nanoparticles with different masses of the seed and the nature of the purge gas were tested. The resulting nanoparticles were thoroughly characterized by a wide range of physicochemical methods: transmission electron microscopy (TEM), high-resolution TEM, scanning electron microscopy–energy dispersive spectroscopy, X-ray diffraction, Brunauer–Emmett–Teller, STSA, Barrett–Joyner–Halenda, dynamic light scattering, and inductively coupled plasma with mass spectrometry. In this work, it has been shown that the IFL method is one of the most promising methods for the synthesis of nanoparticles today, which allows to obtain NPs with a high degree of purity and homogeneity in one stage.