Counter-Intuitive Evaporation in Nanofluids Droplets due to Stick-Slip Nature

Hari Govindha, A. and Katre, Pallavi and Balusamy, Saravanan and Banerjee, Sayak and Sahu, Kirti Chandra (2022) Counter-Intuitive Evaporation in Nanofluids Droplets due to Stick-Slip Nature. Langmuir, 38 (49). pp. 15361-15371. ISSN 0743-7463

Text (Green Open Access)
Langmuir_1.pdf - Published Version
Available under License Creative Commons Attribution.
Download (9MB)

Abstract

We experimentally investigate the evaporation characteristics of a sessile ethanol droplet containing Al2O3 and Cu nanoparticles of sizes 25 and 75 nm on a heated substrate using shadowgraphy and infrared imaging techniques. Our results demonstrate that the droplet contact line dynamics resulting from the presence of various nanoparticles plays a dominant role in the evaporation process. This is in contrast to the widely held assumption that the enhanced evaporation rate observed in sessile nanofluid droplets is due to the higher thermal conductivity of the added nanoparticles. We observe that even though the thermal conductivity of Al2O3 is an order of magnitude lower than that of Cu, droplets containing 25-nm-sized Al2O3 exhibit pinned contact line dynamics and evaporate much more rapidly than droplets containing Cu nanoparticles of both sizes and 75 nm Al2O3 nanoparticles that exhibit stick-slip behavior. We also found that the droplets with different nanoparticles display distinct thermal patterns due to the difference in contact line behavior, which alters the heat transfer inside the droplets. We establish this counter-intuitive observation by analyzing the temporal variations of the perimeter, free surface area, and deposition patterns on the substrate. © 2022 American Chemical Society.

[error in script]

IITH Creators:

IITH Creators	ORCiD
Banerjee, Sayak	https://orcid.org/0000-0002-9595-6456
Sahu, Kirti Chandra	https://orcid.org/0000-0002-7357-1141

Item Type:

Article

Additional Information:

The financial support from Science & Engineering Research Board, India through grant number: CRG/2020/000507 is gratefully acknowledged.

Uncontrolled Keywords:

Alumina; Aluminum oxide; Copper; Evaporation; Heat transfer; Nanofluidics; Nanoparticles; Slip forming; Stick-slip; Thermal conductivity; Thermography (imaging)

Subjects:

Physics > Mechanical and aerospace
Chemical Engineering

Divisions:

Department of Chemical Engineering
Department of Mechanical & Aerospace Engineering

Depositing User:

Ms Palak Jain

Date Deposited:

19 May 2023 12:05

Last Modified:

19 May 2023 12:05

URI:

http://raiithold.iith.ac.in/id/eprint/11492