Coarsening and solidification via solvent-annealing in thin liquid films
We examine solidification in thin liquid films produced by annealing amorphous Alq[subscript 3] (tris-(8-hydroxyquinoline) aluminium) in methanol vapour. Micrographs acquired during annealing capture the evolution of the film: the initially-uniform film breaks up into drops that coarsen, and single...
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| 语言: | en_US |
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Cambridge University Press
2014
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| 在线阅读: | http://hdl.handle.net/1721.1/87630 https://orcid.org/0000-0002-0960-2580 |
| _version_ | 1826195237428527104 |
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| author | Yu, Tony S. Bulovic, Vladimir Hosoi, Anette E. |
| author2 | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science |
| author_facet | Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Yu, Tony S. Bulovic, Vladimir Hosoi, Anette E. |
| author_sort | Yu, Tony S. |
| collection | MIT |
| description | We examine solidification in thin liquid films produced by annealing amorphous Alq[subscript 3] (tris-(8-hydroxyquinoline) aluminium) in methanol vapour. Micrographs acquired during annealing capture the evolution of the film: the initially-uniform film breaks up into drops that coarsen, and single crystals of Alq[subscript 3] nucleate randomly on the substrate and grow as slender ‘needles’. The growth of these needles appears to follow power-law behaviour, where the growth exponent, γ, depends on the thickness of the deposited Alq[subscript 3] film. The evolution of the thin film is modelled by a lubrication equation, and an advection–diffusion equation captures the transport of Alq[subscript 3] and methanol within the film. We define a dimensionless transport parameter, α, which is analogous to an inverse Sherwood number and quantifies the relative effects of diffusion- and coarsening-driven advection. For large α-values, the model recovers the theory of one-dimensional, diffusion-driven solidification, such that γ→1/2. For low α-values, the collapse of drops, i.e. coarsening, drives flow and regulates the growth of needles. Within this regime, we identify two relevant limits: needles that are small compared to the typical drop size, and those that are large. Both scaling analysis and simulations of the full model reveal that γ→2/5 for small needles and γ→0.29 for large needles. |
| first_indexed | 2024-09-23T10:09:34Z |
| format | Article |
| id | mit-1721.1/87630 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:09:34Z |
| publishDate | 2014 |
| publisher | Cambridge University Press |
| record_format | dspace |
| spelling | mit-1721.1/876302022-09-30T19:15:57Z Coarsening and solidification via solvent-annealing in thin liquid films Yu, Tony S. Bulovic, Vladimir Hosoi, Anette E. Massachusetts Institute of Technology. Department of Electrical Engineering and Computer Science Bulovic, Vladimir We examine solidification in thin liquid films produced by annealing amorphous Alq[subscript 3] (tris-(8-hydroxyquinoline) aluminium) in methanol vapour. Micrographs acquired during annealing capture the evolution of the film: the initially-uniform film breaks up into drops that coarsen, and single crystals of Alq[subscript 3] nucleate randomly on the substrate and grow as slender ‘needles’. The growth of these needles appears to follow power-law behaviour, where the growth exponent, γ, depends on the thickness of the deposited Alq[subscript 3] film. The evolution of the thin film is modelled by a lubrication equation, and an advection–diffusion equation captures the transport of Alq[subscript 3] and methanol within the film. We define a dimensionless transport parameter, α, which is analogous to an inverse Sherwood number and quantifies the relative effects of diffusion- and coarsening-driven advection. For large α-values, the model recovers the theory of one-dimensional, diffusion-driven solidification, such that γ→1/2. For low α-values, the collapse of drops, i.e. coarsening, drives flow and regulates the growth of needles. Within this regime, we identify two relevant limits: needles that are small compared to the typical drop size, and those that are large. Both scaling analysis and simulations of the full model reveal that γ→2/5 for small needles and γ→0.29 for large needles. 2014-06-04T18:34:48Z 2014-06-04T18:34:48Z 2013-04 2013-02 Article http://purl.org/eprint/type/JournalArticle 0022-1120 1469-7645 http://hdl.handle.net/1721.1/87630 Yu, Tony S., Vladimir Bulović, and A. E. Hosoi. “Coarsening and Solidification via Solvent-Annealing in Thin Liquid Films.” J. Fluid Mech. 723 (May 2013): 69–90. © Cambridge University Press 2013. https://orcid.org/0000-0002-0960-2580 en_US http://dx.doi.org/10.1017/jfm.2013.115 Journal of Fluid Mechanics Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf Cambridge University Press MIT web domain |
| spellingShingle | Yu, Tony S. Bulovic, Vladimir Hosoi, Anette E. Coarsening and solidification via solvent-annealing in thin liquid films |
| title | Coarsening and solidification via solvent-annealing in thin liquid films |
| title_full | Coarsening and solidification via solvent-annealing in thin liquid films |
| title_fullStr | Coarsening and solidification via solvent-annealing in thin liquid films |
| title_full_unstemmed | Coarsening and solidification via solvent-annealing in thin liquid films |
| title_short | Coarsening and solidification via solvent-annealing in thin liquid films |
| title_sort | coarsening and solidification via solvent annealing in thin liquid films |
| url | http://hdl.handle.net/1721.1/87630 https://orcid.org/0000-0002-0960-2580 |
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