Generation of copper nanoparticles by electro-exploding wire technique for various pressures of the surrounding medium

This paper presents the experimental results on explosion of copper wire at a discharge voltage of 9kV for the generation of Cu nanoparticles in nitrogen environment at different pressures. The current and voltage waveforms for different pressures of the nitrogen gas have been recorded by a current transformer and a high voltage probe. Nanoparticles generated by the electro exploded wire method were characterized by both optical microscopy and transmission electron microscopy. Experiments show that the variation of pressure of nitrogen gas inside the exploding chamber determines the size of the particles formed during the explosion of the copper wire. It is observed that for a pressure of less than 230 mbar of nitrogen gas, the wire does not explode and the copper wire remains intact. Micro particle generation occurred at a pressure of 2.3×10 2 mbar of nitrogen gas and nanoparticles were formed when the pressure was further increased to 1×10 3 mbar. Experimental results show that we could deposit maximum energy into the metal core when the wire was exploded by working in the high pressure regime of the nitrogen gas resulting in the production of nanoparticles. Transmission electron microscopy reveals the size of the nanoparticles to be in the range of 35 to 75 nm.