Nanocomposites and nanomaterials
Electrotechnical complex for production of nanostructured and ultradisperse materials by means of volumetric electrospark erosion 
S.A. Lapshin1, K.G. Lopatko1, Y. G. Aftandiliants 1, O.V. Zazimko1,                  T.A. Tmenova2,3, A.N. Veklich2, V.F. Boretskij2, Y. Cressault3, F. Valensi3
1 National University of Life and Environmental Sciences of Ukraine, 15, Heroyiv Oborony Str., Kiev, 0304, Ukraine.
E-mail: lapschinserega@ukr.net
2 Taras Shevchenko National University of Kyiv; Faculty of Radio Physics, Electronics and Computer Systems; 64, Volodymyrs`ka Str., Kyiv, Ukraine.
3 Université de Toulouse; UPS, INPT; LAPLACE (Laboratoire Plasma et Conversion d’Energie); 118 route de Narbonne, F-31062, Toulouse Cedex 9, France.
The existing level of development of science and technology, for many reasons, forces specialists to consider more promising and topical areas, including those related to the integration of modern development of technologies associated with obtaining nanoscale objects.
Nowadays, electrospark technologies for production of metal nanoscale and ultradisperse powders and alloys are one of the most effective methods that meet the requirements of the present scientific and applied problems. These technologies find their application in processes of coagulation water treatment, obtainment of nano- and ultradisperse metal powders, and, moreover, they are being tested as a method of bifunctional materials’ fabrication.
Implementation of the low-voltage spark discharges was performed on technological unit, consisting of pulse generator, control unit, discharge chamber, and other measuring and auxiliary devices. Load on electrodes caused the occurrence of a current flow along the chain of randomly located granules in the stochastic switching mode. Study of the technological parameters’ influence on dispersion and morphology of products of metal granules’ erosion as a result of local electrospark discharges was performed through control over the discharge circuit’s electrical parameters.
During the synthesis, the main parameters of the discharge circuit were monitored as: capacitance of the working capacitor, voltage, pulse duration, duty cycle, frequency, which directly influenced the size and morphology of synthesized nanoparticles.
Investigation of plasma channels in contact areas between metal granules was carried out using the optical emission spectroscopy (OES) techniques, which allow to perform the noninvasive and express analysis and quantitatively determine numerous elements in a wide range of concentrations with acceptable accuracy.
 Knowledge of the underwater electric spark plasma parameters, parameters of the discharge circuit, makes it possible to estimate the energy input and, correspondingly, to clarify the paths of energy dissipation of such process, directed on obtaining nanoscale objects with given properties.