Controlling self-assembly and buckling in nano fluid droplets through vapour mediated interaction of adjacent droplets

Hegde, O and Kabi, P and Agarwal, S and Basu, S (2019) Controlling self-assembly and buckling in nano fluid droplets through vapour mediated interaction of adjacent droplets. In: Journal of Colloid and Interface Science, 541 . pp. 348-355.

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Abstract

Hypothesis: Sessile droplets of contrasting volatilities can communicate via long range (∼O (1) mm) vapour-mediated interactions which allow the remote control of the flow driven self-assembly of nanoparticles in the drop of lower volatility. This allows morphological control of the buckling instability observed in evaporating nanofluid droplets. Experiments: A nanofluid droplet is dispensed adjacent to an ethanol droplet. Asymmetrical adsorption induced Marangoni flow (∼O (1) mm/s) internally segregates the particle population. Particle aggregation occurs preferentially on one side of the droplet leaving the other side to develop a relatively weaker shell which buckles under the effect of evaporation driven capillary pressure. Findings: The inter-droplet distance is varied to demonstrate the effect on the precipitate shape (flatter to dome shaped) and the location of the buckling (top to side). In addition to being a simple template for hierarchical self-assembly, the presented exposition also promises to enhance mixing rates (∼1000 times) in droplet-based bioassays with minimal contamination.

Item Type:	Journal Article
Publication:	Journal of Colloid and Interface Science
Publisher:	Academic Press Inc.
Additional Information:	The copyright for this article belongs to Academic Press Inc.
Keywords:	Agglomeration; Buckling; Nanofluidics; Remote control; Self assembly, Buckling instabilities; Hierarchical self-assembly; Inter-droplet distance; Marangoni convection; Mediated interaction; Morphological control; Nanofluids; Particle aggregation, Drops, alcohol; nanoparticle, adsorption; advection; Article; capillary pressure; concentration (parameter); contact angle; diffusion; evaporation; molecular interaction; nanofluidics; priority journal; reduction (chemistry); surface tension; vapor; wettability
Department/Centre:	Division of Interdisciplinary Sciences > Interdisciplinary Centre for Energy Research Division of Mechanical Sciences > Mechanical Engineering
Date Deposited:	30 Nov 2022 09:46
Last Modified:	30 Nov 2022 09:46
URI:	https://eprints.iisc.ac.in/id/eprint/78351

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