Automated system for the synthesis of nanostructures via arc-discharge in liquids

L Hernández-Tabares, J G Darias-González, J Arteche-Díaz, E Carrillo-Barroso, L M Ledo-Pereda and L F Desdín-García

Abstract

Submerged arc discharge in liquids has shown to be a promising method to synthesize a wide variety of nanomaterials. However, it requires an accurate arc current control to ensure the desired purity and structure of the products. A fluctuating arc current increases the dispersion in size distribution, as well as in the obtained nanoparticles structure pattern. Consequently, the arc current stability is essential to ensure the product homogeneity and quality. A system which ensures high stability of the arc discharge is presented. It has three basic elements: an electrode gap micropositioning system controlled by a feedback arc current measurement, a current's stabilization element and a data acquisition system to record the magnitudes of the relevant physical parameters. The most suitable algorithm for micropositioning system was determined. The utilization of a step motor gave an additional advantage in measuring the anode displacement. The employed stabilization element improves the current and power stability by 4 and 2.7 times, respectively. The data acquisition system allows taking control and information about the relevant parameters of the process and the interaction between them. This system, based on direct arc current measurement, is superior in terms of achieving higher stability and current sensibility, to the ones based on arc voltage or arc light emission. It is also an adaptable tool to carry on further experiments