Experimental Investigation of the Effect of the Ambient Gas on Evaporating Sessile Drops

S. David; Khellil Sefiane; Lounes Tadrist

doi:10.4028/www.scientific.net/DDF.258-260.461

Paper Titles

A Sulfur Diffusion Investigation in Metal and Oxide Phases
p.433

Effect of Structure on Water Diffusion in Hydrophilic Polymers
p.442

Interaction between Stress and Diffusion in Polymers
p.447

Two-Phase Hygrothermal Diffusion in an Epoxy Adhesive
p.453

Experimental Investigation of the Effect of the Ambient Gas on Evaporating Sessile Drops
p.461

On the Dynamics of Wetting of Water-Methanol Volatile Sessile Drops on Smooth Substrates
p.469

Diffusion and Segregation in Bulk Nanomaterials and Thin Layers
p.475

Phenomenological Aspects of Grain Boundary Diffusion
p.483

The Grain Boundary Wetting in the Sn– 25 at% In Alloys
p.491

HomeDefect and Diffusion ForumDefect and Diffusion Forum Vols. 258-260Experimental Investigation of the Effect of the...

Experimental Investigation of the Effect of the Ambient Gas on Evaporating Sessile Drops

Abstract:

This paper presents the results of an experimental study of evaporating sessile drops in a controlled environment. The experimental setup allowed the investigation of the evaporation rate of sessile drops under reduced pressure (40 to 1000 mbar) and various ambient gases. Sessile drops of initial volume 2.5μL are deposited on substrates and left to evaporate in a controlled atmosphere. The effect of reducing pressure on the evaporation rate as well as changing the ambient gas is studied. Three different gases are used; namely Helium, Nitrogen and Carbon Dioxide. The role of vapour diffusion as a limiting mechanism for evaporation is studied. It is found that in all cases the evaporation rate is limited by the mass diffusion in the ambient gas provided that interfacial conditions are properly accounted for. This includes important evaporative cooling observed at higher evaporation rates and lower substrate thermal conductivity.