Characterizing dynamic wetting behaviour on irregularly roughened surfaces

Elms, Justin (2018) Characterizing dynamic wetting behaviour on irregularly roughened surfaces. Masters thesis, Memorial University of Newfoundland.

[English] PDF - Accepted Version Available under License - The author retains copyright ownership and moral rights in this thesis. Neither the thesis nor substantial extracts from it may be printed or otherwise reproduced without the author's permission. Download (2MB)

Abstract

Surface wettability describes the behavior of liquids on substrates and their ability to remain in contact with them. Quantification of wettability is often reduced to a measurement of the contact angle that a liquid droplet makes on the surface. Although this practice has become ubiquitous in the literature, a growing number of researchers have voiced concerns that static contact angles alone cannot fully describe surface wetting properties. Our research findings fall in line with this sentiment and highlight some of the difficulties encountered when quantifying dynamic wetting behavior. The wetting dynamics of more than 300 droplets were studied on randomly roughened surfaces to demonstrate the range over which advancing and receding contact angles can vary. Factors such as droplet size, rate of volume change, and shape fitting algorithms affected measured contact angles. The relation between static and dynamic contact angle data was compared based on empirical models developed by others [Furmidge J. Colloid Sci., 1962, 17(4), 309; Xiu et al., J. Phys. Chem. C, 2008, 112(30), 11403]. The results of these comparisons demonstrate that static contact angles alone are not enough to characterize irregularly roughened surfaces, and that more information related to dynamic wetting behavior, such as sliding angles and hysteresis, is essential.

Actions (login required)

View Item