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Abstract

The evaporation of colloidal dispersions is an elegant and straightforward route to controlled self-assembly of particles on a solid surface. In particular, the evaporation of particle laden drops placed on solid substrates has received considerable attention for more than two decades. Such particle filled drops upon complete evaporation of the solvent leave behind a residue, commonly called particulate deposit pattern. In these patterns, typically, more particles accumulate at the edge compared to the interior, a feature observed when coffee drops evaporate. Consequently, such evaporative patterns are called coffee stains. In this article, the focus is on the evaporation of highly dilute suspension drops containing particles of larger diameters ranging from 3 to 10 μm drying on solid substrates. This helps us to investigate the combined role of gravity-driven settling of particles and capillary flow-driven particle transport on pattern formation in drying drops. In the highly dilute concentration limit, the evaporative patterns are found to show a transition, from a monolayer deposit that consists of a single layer of particles, to a multilayer deposit as a function of particle diameter and initial concentration of particles in the drying drop. Moreover, the spatial distribution of particles as well as the ordering of particles in the deposit patterns are found to be particle size dependent. It is also seen that the order–disorder transition, a feature associated with the organization of particles at the edge of the deposit, observed typically at moderate particle concentrations, disappears at the highly dilute concentrations considered here. The evaporation of drops containing particles of 10 μm diameter, where the effect of gravity on the particle becomes significant, leads to uniform deposition of particles, i.e, suppression of the coffee-stain effect and to the formation of two-dimensional percolating networks.

Details

1007418
Identifier / keyword
Supplemental data
Langmuir. 2021 Apr. 02, v. 37, no. 14 p.4395-4402 American Chemical Society, NAL-AP-2-clean
Title
Further Insights into Patterns from Drying Particle Laden Sessile Drops
Correspondence author
Publication title
Volume
37
Issue
14 p.4395-4402
Pages
p. 4395-4402
Number of pages
8
Publication year
2021
Publisher
American Chemical Society
ISSN
1520-5827
Source type
Scholarly Journal
Peer reviewed
Yes
Format availability
Available from publisher's site
Language of publication
English
Document type
Journal Article
Holding library
DNAL
Accession number
IND607338236
ProQuest document ID
2986727153
Document URL
https://www.proquest.com/scholarly-journals/further-insights-into-patterns-drying-particle/docview/2986727153/se-2?accountid=208611
Last updated
2024-03-27
Database
ProQuest One Academic