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Surfactant Control of Coffee Ring Formation in Carbon Nanotube Suspensions

[Image: see text] The coffee ring effect regularly occurs during the evaporation of colloidal droplets and is often undesirable. Here we show that adding a specific concentration of a surfactant can mitigate this effect. We have conducted experiments on aqueous suspensions of carbon nanotubes that w...

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Autores principales: Howard, N. S., Archer, A. J., Sibley, D. N., Southee, D. J., Wijayantha, K. G. U.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: American Chemical Society 2023
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9878724/
https://www.ncbi.nlm.nih.gov/pubmed/36607610
http://dx.doi.org/10.1021/acs.langmuir.2c01691
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author Howard, N. S.
Archer, A. J.
Sibley, D. N.
Southee, D. J.
Wijayantha, K. G. U.
author_facet Howard, N. S.
Archer, A. J.
Sibley, D. N.
Southee, D. J.
Wijayantha, K. G. U.
author_sort Howard, N. S.
collection PubMed
description [Image: see text] The coffee ring effect regularly occurs during the evaporation of colloidal droplets and is often undesirable. Here we show that adding a specific concentration of a surfactant can mitigate this effect. We have conducted experiments on aqueous suspensions of carbon nanotubes that were prepared with cationic surfactant dodecyltrimethylammonium bromide added at 0.2, 0.5, 1, 2, 5, and 10 times the critical micelle concentration. Colloidal droplets were deposited on candidate substrates for printed electronics with varying wetting characteristics: glass, polyethylene terephthalate, fluoroethylene propylene copolymer, and polydimethylsiloxane. Following drying, four pattern types were observed in the final deposits: dot-like, uniform, coffee ring deposits, and combined patterns (coffee ring with a dot-like central deposit). Evaporation occurred predominantly in constant contact radius mode for most pattern types, except for some cases that led to uniform deposits in which early stage receding of the contact line occurred. Image analysis and profilometry yielded deposit thicknesses, allowing us to identify a coffee ring subfeature in all uniform deposits and to infer the percentage coverage in all cases. Importantly, a critical surfactant concentration was identified for the generation of highly uniform deposits across all substrates. This concentration resulted in visually uniform deposits consisting of a coffee ring subfeature with a densely packed center, generated from two distinct evaporative phases.
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spelling pubmed-98787242023-01-27 Surfactant Control of Coffee Ring Formation in Carbon Nanotube Suspensions Howard, N. S. Archer, A. J. Sibley, D. N. Southee, D. J. Wijayantha, K. G. U. Langmuir [Image: see text] The coffee ring effect regularly occurs during the evaporation of colloidal droplets and is often undesirable. Here we show that adding a specific concentration of a surfactant can mitigate this effect. We have conducted experiments on aqueous suspensions of carbon nanotubes that were prepared with cationic surfactant dodecyltrimethylammonium bromide added at 0.2, 0.5, 1, 2, 5, and 10 times the critical micelle concentration. Colloidal droplets were deposited on candidate substrates for printed electronics with varying wetting characteristics: glass, polyethylene terephthalate, fluoroethylene propylene copolymer, and polydimethylsiloxane. Following drying, four pattern types were observed in the final deposits: dot-like, uniform, coffee ring deposits, and combined patterns (coffee ring with a dot-like central deposit). Evaporation occurred predominantly in constant contact radius mode for most pattern types, except for some cases that led to uniform deposits in which early stage receding of the contact line occurred. Image analysis and profilometry yielded deposit thicknesses, allowing us to identify a coffee ring subfeature in all uniform deposits and to infer the percentage coverage in all cases. Importantly, a critical surfactant concentration was identified for the generation of highly uniform deposits across all substrates. This concentration resulted in visually uniform deposits consisting of a coffee ring subfeature with a densely packed center, generated from two distinct evaporative phases. American Chemical Society 2023-01-06 /pmc/articles/PMC9878724/ /pubmed/36607610 http://dx.doi.org/10.1021/acs.langmuir.2c01691 Text en © 2023 The Authors. Published by American Chemical Society https://creativecommons.org/licenses/by/4.0/Permits the broadest form of re-use including for commercial purposes, provided that author attribution and integrity are maintained (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Howard, N. S.
Archer, A. J.
Sibley, D. N.
Southee, D. J.
Wijayantha, K. G. U.
Surfactant Control of Coffee Ring Formation in Carbon Nanotube Suspensions
title Surfactant Control of Coffee Ring Formation in Carbon Nanotube Suspensions
title_full Surfactant Control of Coffee Ring Formation in Carbon Nanotube Suspensions
title_fullStr Surfactant Control of Coffee Ring Formation in Carbon Nanotube Suspensions
title_full_unstemmed Surfactant Control of Coffee Ring Formation in Carbon Nanotube Suspensions
title_short Surfactant Control of Coffee Ring Formation in Carbon Nanotube Suspensions
title_sort surfactant control of coffee ring formation in carbon nanotube suspensions
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9878724/
https://www.ncbi.nlm.nih.gov/pubmed/36607610
http://dx.doi.org/10.1021/acs.langmuir.2c01691
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