Abstract: Processes for the simultaneous and selective growth of single walled and multiwalled carbon nanotubes in a single set of experiments are disclosed. The processes may include preparing a graphite electrode rod containing catalyst selected from Fe, Co, Ni, and a mixture thereof, acting as an anode. The process may include preparing another graphite electrode rod, each electrode having a distal and a proximal end. The process may include placing the above said two electrodes parallel to each other and their axis being substantially aligned in a chamber. The process may further include creating a DC-arc discharge inside the chamber by applying a DC-current voltage. The process may further include an cooling assembly having a cooling coil that surrounds the two electrodes. The cooling assembly may be used to maintain a temperature gradient that permits the depositing of single walled and multiwalled carbon nanotubes simultaneously in one experiment.

Abstract: The present invention provides a process for the simultaneous and selective growth of single walled and multiwalled carbon nanotubes using electric arc discharge technique. According to present development it is possible to synthesise and collect catalyst free carbon nanotubes from cathode deposit. A mechanism of cooling coil arrangement was designed and used inside the arc discharge chamber so as to be capable to grow sufficient amount of single walled carbon nanotubes in the form of webs surrounding the coil. The present invention offers a scalable way for producing both SWNTs and MWNTs in the single run.