Evaporation of picoliter droplets on surfaces with a range of wettabilities and thermal conductivities

Talbot, Emma L.; Berson, Arganthaël; Brown, Philip S.; Bain, Colin D.

doi:10.1103/physreve.85.061604

Evaporation of picoliter droplets on surfaces with a range of wettabilities and thermal conductivities

Talbot, Emma L.; Berson, Arganthaël; Brown, Philip S.; Bain, Colin D.

Authors

Emma L. Talbot

Arganthaël Berson

Philip S. Brown

Professor Colin Bain c.d.bain@durham.ac.uk
Pro-Vice-Chancellor (Research)

Abstract

The evaporation of picoliter water and ethanol droplets generated by drop-on-demand inkjet printing was investigated on substrates with apparent contact angles between 10∘ and 135∘ and thermal conductivities between 0.25 and 149 Wm−1K−1. Drying times were calculated from a diffusion-limited model for droplets with both pinned and moving contact lines as a function of droplet diameter and apparent contact angle. Droplets with a moving contact line take longer to dry on hydrophilic substrates than pinned droplets. The difference in drying times between evaporative modes vanishes at large apparent contact angles. Hence similar drying times are obtained for both modes on hydrophobic substrates. The predicted drying times for glass and silicon substrates were in good quantitative agreement with experimental data, suggesting that thermal effects are negligible for substrates of these base materials. However, on a PTFE substrate which has a lower thermal conductivity more relevant to inkjet printing, evaporative cooling reduces the evaporation rate causing drying times to be underpredicted by isothermal models.

Citation

Talbot, E. L., Berson, A., Brown, P. S., & Bain, C. D. (2012). Evaporation of picoliter droplets on surfaces with a range of wettabilities and thermal conductivities. Physical review E: Statistical, nonlinear, and soft matter physics, 85(6), Article 061604. https://doi.org/10.1103/physreve.85.061604

Journal Article Type	Article
Publication Date	Jun 26, 2012
Deposit Date	Jun 27, 2012
Publicly Available Date	Jun 24, 2014
Journal	Physical review . E, Statistical, nonlinear, and soft matter physics
Print ISSN	1539-3755
Electronic ISSN	1550-2376
Publisher	American Physical Society
Peer Reviewed	Peer Reviewed
Volume	85
Issue	6
Article Number	061604
DOI	https://doi.org/10.1103/physreve.85.061604

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Copyright Statement
Reprinted with permission from the American Physical Society: Talbot, E.L., Berson, A., Brown, P.S. and Bain, C.D. Physical Review E, 85, 061604, 2012. © 2012 by the American Physical Society. Readers may view, browse, and/or download material for temporary copying purposes only, provided these uses are for noncommercial personal purposes. Except as provided by law, this material may not be further reproduced, distributed, transmitted, modified, adapted, performed, displayed, published, or sold in whole or part, without prior written permission from the American Physical Society.