Issue 36, 2009

Measurements and simulations of the near-surface composition of evaporating ethanol–water droplets

Abstract

The evolving composition of evaporating ethanolwater droplets (initially 32.6 or 45.3 μm radius) is probed by stimulated Raman scattering over the period 0.2 to 3 ms following droplet generation and with a surrounding nitrogen gas pressure in the range 10 to 100 kPa. The dependence of the evaporation rate on the relative humidity of the surrounding gas phase is also reported. The measured data are compared with both a quasi-steady state model and with numerical simulations of the evaporation process. Results from the numerical simulations are shown to agree closely with the measurements when the stimulated signal is assumed to arise from an outer shell with a probe depth of 2.9 ± 0.4% of the droplet radius, consistent with a previous determination. Further, the time-dependent measurements are shown to be sensitive to the development of concentration gradients within evaporating droplets. This represents the first direct measurement of the spatial gradients in composition that arise during the evaporation of aerosol droplets and allows the influence of liquid phase diffusion within the condensed phase on droplet evaporation to be examined.

Graphical abstract: Measurements and simulations of the near-surface composition of evaporating ethanol–water droplets

Article information

Article type
Paper
Submitted
26 Feb 2009
Accepted
07 May 2009
First published
03 Jun 2009

Phys. Chem. Chem. Phys., 2009,11, 7780-7791

Measurements and simulations of the near-surface composition of evaporating ethanolwater droplets

C. J. Homer, X. Jiang, T. L. Ward, C. J. Brinker and J. P. Reid, Phys. Chem. Chem. Phys., 2009, 11, 7780 DOI: 10.1039/B904070F

To request permission to reproduce material from this article, please go to the Copyright Clearance Center request page.

If you are an author contributing to an RSC publication, you do not need to request permission provided correct acknowledgement is given.

If you are the author of this article, you do not need to request permission to reproduce figures and diagrams provided correct acknowledgement is given. If you want to reproduce the whole article in a third-party publication (excluding your thesis/dissertation for which permission is not required) please go to the Copyright Clearance Center request page.

Read more about how to correctly acknowledge RSC content.

Social activity

Spotlight

Advertisements