Characterization and Optimization of Arc Spray Process Parameters for Synthesis of TiO<SUB>2</SUB> Nanoparticles

Abstract

This article presents the process characterization and optimization of the nanoparticle fabrication process known as the Submerged Arc Spray Nanoparticle Synthesis System (SANSS) by using a developed on-line nanoparticle measurement system and Taguchi method. Without process characterization and optimization, preliminary experimental results indicated that the average secondary diameter of prepared nanoparticles, widely ranging from 45 to 350 nm, are significantly influenced by the process parameters, such as operating pressure, temperature, electrical current and type of dielectric liquids employed. To improve this, an on-line particle sizing system was developed and deployed to measure the particle dimension and analyze the nanoparticle synthesis process. Experiments based on Taguchi method were then conducted to investigate the optimum process parameters for producing nanoparticles with improved properties, such as particle size and uniformity. The experimental results revealed that the pulsed peak voltage and the pulsed peak current have the most significant effect on decreasing the secondary particle size of the TiO2 nanoparticles and that the on-time duration and off-time duration also play an important predominant effect. Using the optimized process parameters, the average secondary diameter of prepared TiO2 particles was reduced from 160 to 65 nm and the range of particle size disparity was narrowed from 300 to 170 nm. The primary particle size observed from TEM results also confirmed a significant reduction of the averaged TiO2 nanoparticle diameter and size disparity.