Understanding nanoparticle formation by a wire explosion process through experimental and modelling studies

Abstract

A wire explosion process (WEP) has been used to produce nano aluminium powder in nitrogen, argon and helium atmospheres. The impact of energy deposited into the exploding conductor on the size and shape of the particles was analysed using TEM analysis, which forms the first part of the study. It is observed that the higher the energy deposited, the smaller the particles formed. In the second part, modelling studies were carried out by solving the general dynamic equation through the nodal approach, and the particle size distributions were predicted. It is realized that, at the point of high saturation ratio and nucleation rate, the size of the critical nucleus formed is low. The particle size distribution predicted by the model correlates well with the experimental results. Time-series analysis of particle formation indicates that particles of lower dimensions form and, in the process of coagulation, larger particles are formed. It is realized that the plasma formed during the explosion plays a major role in the particle formation, and the modelling studies confirm that particle formation is not an instantaneous process but requires a certain time period to form stable sizes and shapes.

Aerosol synthesis and reactive behavior of faceted aluminum nanocrystals

“…This technique uses a high density current pulsed through an Al wire to create a microplasma, which yields ultrafine aluminum after a quench. Sindhu et al [8] combined experimental and modeling studies to fully characterize the explosive Al wire process. Anderson and Foley.…”

Surface modification and submicron structure of carbon fibers through high current pulse

“…3(b) presents the particles and broken fibers, as two typical productions. If the electrically exploded conductor is metal wire, the productions by electrical explosion process are no other than particles, which have been discussed widely [12,18]. However, in the case of carbon fiber, the particles and broken fibers coexisted, implying the electrical explosion process is incomplete.…”

“…Namely, there is a dynamic equilibrium between the selfmagnetic field force and the plasma thermal stress, determining the development of plasma gas. Based on the steady-state solution of the magneto-hydrodynamic (MHD) equations, in the case of isotropic pressure, the radius of the plasma column is given by r ¼ ði=pÞ ffiffiffiffiffiffiffiffiffiffiffiffiffi m=4 p p , where i is the current going through the carbon fiber, m is the plasma magnetic conductivity, and p is the plasma pressure [12]. Clearly, the radius of the plasma gas column is closely related to the discharge current and plasma pressure.…”

“…The mechanisms governing the electrical explosion are mainly attributed to the thermal instability due to Joule heating by high density current [10]. During the electrical explosion process, a number of phenomena, including instabilities, shunting discharges, and stratification, develop which makes the underlying mechanism significantly complicated [11,12].…”

A Review of Methods for Synthesis of Al Nanoparticles

“…Also Sindhu et al proposed a modelling of the nanoparticles formation in the wire explosion process. It was found that the plasma formed during the explosion plays a major role in the particle formation, and the modelling studies confirm that particle formation is not an instantaneous process but requires a certain time period to form stable sizes and shapes 41 . Generally the wire explosion technique has several advantages for the generation of nanoparticles.…”