Non-Newtonian nanofluids mediated 15-fold enhancement of mass transfer for two-phase flow systems in microchannel

Abstract

Microfluidic systems have been more popular in recent years because of its multifunctional advantages, such as the higher level of process intensification. The mass-transfer properties can further be improved by the presence of the slug flow regime in the microdomain for biphasic flow systems. Microdomain, geometrical considerations, non-Newtonian fluid and nanofluid have been independently being investigated as a tool of process intensification. To the best of our understanding, the four-in-one method of process intensification has not been studied till date hence, new systems are being investigated to bridge the gap. In this work, we describe the combination of three enhancing factors - microdomain, slug flow and non-Newtonian nanofluids (NNnF) on hydrodynamic and mass transfer studies for two-phase flow systems. The effect of non-Newtonian fluid (NNF) on the flow pattern and mass transport properties of an immiscible liquid-liquid system in straight and helical microchannels with internal diameters of 0.15 mm and 0.25 mm is being explored experimentally as well with CFD simulations. The range of slug flow has been increased along with enhancement of mass transfer coefficient with the introduction of non-Newtonian nanofluid. Unprecedentedly the addition of 0.5% (w/v) carboxy methyl cellulose (CMC) and Nickel (Ni) nanoparticles has resulted in fifteen times enhancement of mass transfer coefficient.