Evaporation of water-in-oil microemulsion droplet

Fuente: arXiv
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Main Authors: Krishan, Bal, Rastogi, Preetika, Rao, D. Chaitanya Kumar, Kaisare, Niket S., Basavaraj, Madivala G., Basu, Saptarshi
Format: Preprint
Published: 2024
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author Krishan, Bal
Rastogi, Preetika
Rao, D. Chaitanya Kumar
Kaisare, Niket S.
Basavaraj, Madivala G.
Basu, Saptarshi
author_facet Krishan, Bal
Rastogi, Preetika
Rao, D. Chaitanya Kumar
Kaisare, Niket S.
Basavaraj, Madivala G.
Basu, Saptarshi
contents Emulsion fuels have the potential to reduce both particulate matter and NOx emissions and can potentially improve the efficiency of combustion engines. However, their limited stability remains a critical barrier to practical use as an alternative fuel. In this study, we explore the evaporation behavior of thermodynamically stable water-in-oil microemulsions. The water-in-oil microemulsion droplets prepared from different types of oil were acoustically levitated and heated using a continuous laser at different irradiation intensities. We show that the evaporation characteristics of these microemulsions can be controlled by varying water-to-surfactant molar ratio (ω) and volume fraction of the dispersed phase (ϕ). The emulsion droplets undergo three distinct stages of evaporation, namely pre-heating, steady evaporation, and unsteady evaporation. During the steady evaporation phase, increasing ϕ reduces the evaporation rate for a fixed ω. It is observed that the evaporation of microemulsion is governed by the complex interplay between its constituents and their properties. We propose a parameter (η) denoting the volume fraction ratio between volatile and non-volatile components, which indicates the cumulative influence of various factors affecting the evaporation process. The evaporation of microemulsions eventually leads to the formation of solid spherical shells, which may undergo buckling. The distinction in the morphology of these shells is explored in detail using SEM imaging.
format Preprint
id arxiv_https___arxiv_org_abs_2408_15780
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Evaporation of water-in-oil microemulsion droplet
Krishan, Bal
Rastogi, Preetika
Rao, D. Chaitanya Kumar
Kaisare, Niket S.
Basavaraj, Madivala G.
Basu, Saptarshi
Fluid Dynamics
Emulsion fuels have the potential to reduce both particulate matter and NOx emissions and can potentially improve the efficiency of combustion engines. However, their limited stability remains a critical barrier to practical use as an alternative fuel. In this study, we explore the evaporation behavior of thermodynamically stable water-in-oil microemulsions. The water-in-oil microemulsion droplets prepared from different types of oil were acoustically levitated and heated using a continuous laser at different irradiation intensities. We show that the evaporation characteristics of these microemulsions can be controlled by varying water-to-surfactant molar ratio (ω) and volume fraction of the dispersed phase (ϕ). The emulsion droplets undergo three distinct stages of evaporation, namely pre-heating, steady evaporation, and unsteady evaporation. During the steady evaporation phase, increasing ϕ reduces the evaporation rate for a fixed ω. It is observed that the evaporation of microemulsion is governed by the complex interplay between its constituents and their properties. We propose a parameter (η) denoting the volume fraction ratio between volatile and non-volatile components, which indicates the cumulative influence of various factors affecting the evaporation process. The evaporation of microemulsions eventually leads to the formation of solid spherical shells, which may undergo buckling. The distinction in the morphology of these shells is explored in detail using SEM imaging.
title Evaporation of water-in-oil microemulsion droplet
topic Fluid Dynamics
url https://arxiv.org/abs/2408.15780