Dynamical aspects of nanoparticle formation by wire explosion process

P Ranjan,R Sarathi,L Chen,I Cotton,H Suematsu,D H Nguyen,S R Chakravarthy,R Jayaganthan

doi:10.1088/2632-959x/ab97ec

Abstract

Copper nanoparticles (NPs) were produced by wire explosion process (WEP) and it was noted that the amount of energy (E) deposited on the wire and the ambient pressure play a major role on the size of particles formed. Dynamic diffusion and condensation processes of NPs formation by WEP were modelled. Calculations of critical size of embryo, activation energy and nucleation rate of the formation of NPs in WEP were made considering classical homogeneous nucleation theory. Decrease in critical size of nuclei and activation energy, increase in nucleation rate with high E (540 J) and low operating pressure (10 kPa) confirm the formation of small size NPs (26 nm). Different cooling rates due to unsymmetrical shape of the vapour cloud has been identified as the cause for generating mixed particle sizes. The qualitative analysis conducted in this work validates the obtained experimental results and can be used as a design tool for industrial apparatus to produce NPs in bulk.

Highlights

Nanotechnology provides a systematic control on the morphology of functional nanomaterials and its unique characteristics have potential applications in catalysis, nano-manufacturing, photonics, sensor technology, environmental remediation etc (Rogers et al 2015)
Based on the known facts, the present study aims to calculate through Fick’s diffusion, the kinetics and concentration profile of the vapour/plasma generated in wire explosion process (WEP) as a function of time with the radial distance of the wire vapour
Diffusion of metal vapour/plasma of spherical geometry formed after the explosion was calculated by Fick’s second law

Summary

Introduction

Nanotechnology provides a systematic control on the morphology of functional nanomaterials and its unique characteristics have potential applications in catalysis, nano-manufacturing, photonics, sensor technology, environmental remediation etc (Rogers et al 2015). The principle of wire explosion process (WEP) is based on the pulsed current injection through the conducting wire (mostly metal) to vaporise it after the joule heating (Kotov 2003) It utilizes the wide difference in temperature and density of the vapour and that of the ambient fluid which acts as the cooling medium. The kinetics would lead to the different morphology of formed NPs as shown by Simchi et al 2007 for Silver and Cu-Tin alloy in vapour phase condensation process. Based on the known facts, the present study aims to calculate through Fick’s diffusion, the kinetics and concentration profile of the vapour/plasma generated in WEP as a function of time with the radial distance of the wire vapour. The variation in nucleation rate considering the homogeneous nucleation in vapour phase is elaborated in the present work

Experimental details

Results and analysis

Conclusions