Investigation of the Energy Balance in the Spark Discharge Generator for Nanoparticles Synthesis

Abstract

Optimization of Serratia nematodiphila using Response surface methodology to silver nanoparticles synthesis for aquatic pathogen control S Rajeshkumar and C Malarkodi Abstract. In this paper we investigate the balance of energy in the discharge circuit of a spark discharge generator (SDG) for nanoparticles synthesis. The released energy consists of several parts: the energy in a discharge gap and the energy dissipated in the other elements of the circuit. In turn, in the gap a one part of the energy releases in preanode and precathode regions and the other part in an arc between electrodes. We measured these parts and proposed ways to optimize energy efficiency of the nanoparticles production. IntroductionNanoparticles of ultra-small sizes (1 − 10 nm) are in demand for a number of promising applications: gas and optical sensors (Ag, SnO 2 , etc.) [1], luminophores (Si, Ge, etc.), different methods of aerosol printing [2], manufacturing of inks for jet printing (Ag, Al, Si, Ge, SiO 2 , C, etc.). With these inks by methods of printed electronics it is possible to create transistors [3], the elements of solar panels [4] (Si, Ag, Al, etc.), antennas, and other devices.There are various methods of nanoparticles gas-phase synthesis: the electric explosion of wires, the laser vaporization of the target, the electrical erosion of electrodes in the pulsed gas discharge. The electric explosion, in this series, was historically the first method, which gives nanoparticles with a large mass yield of the order of hundreds of grams per hour, but the resulting particles are of sufficiently large diameters, on the order of 20 − 300 nm. The electric explosion is by far the most energy-efficient gas-phase method (∼ 50 kWh/kg), as all the energy input goes directly to the evaporation of a wire and particle formation. The laser vaporization method produces much smaller particles (10 − 30 nm), but requires specially trained targets of compressed powder. Energy costs account for 80 − 300 kWh/kg. The gas-discharge synthesis is a unique method that allows one to obtain particles of very small size, up to clusters of a few atoms [5]. Other advantages include possibility to obtain nanoparticles of any conductive material, including metals and doped semiconductors. There are only two requirements to a workpiece material, not too high electrical resistance and an ability to manufacture a rod from the material to be used as an electrode. At the same time, this method requires a lot of specific energy input about of 1600 kWh/kg. For the industrial use of the method it is of interest to find ways to minimize particle synthesis energy.In the aerosol SDG a capacitor charged to a high voltage discharges through a system of the two electrodes with the gas gap between them. The energy releases in the discharge gap (useful energy) and in the capacitor and busbars. It is clear that heat released out of the gap should be kept to a minimum, this can be done by reducing the resistance of an external part of the circuit. The ratio of the energy released ...