Physics – Condensed Matter – Soft Condensed Matter
Scientific paper
2005-11-26
Physics
Condensed Matter
Soft Condensed Matter
14 pages, 7 figures, to be published in Journal of Colloid and Interface Science
Scientific paper
Contact angle hysteresis of a macroscopic droplet on a heterogeneous but flat substrate is studied using the interface displacement model. First, the apparent contact angle of a droplet on a heterogeneous surface under the condition of constant volume is considered. By assuming a cylindrical liquid-vapor surface (meniscus) and minimizing the total free energy, we derive an equation for the apparent contact angle, which is similar but different from the well-known Cassie's law. Next, using this modified Cassie's law as a guide to predict the behavior of a droplet on a heterogeneous striped surface, we examine several scenarios of contact angle hysteresis using a periodically striped surface model. By changing the volume of the droplet, we predict a sudden jump of the droplet edge, and a continuous change of the apparent contact angle at the edge of two stripes. Our results suggest that as drop volume is increased (advancing contact lines), the predominant drop configuration observed is the one whose contact angle is large; whereas, decreasing drop volume from a large value (receding contact lines) yields drop configuration that predominantly exhibit the smaller contact angle.
No associations
LandOfFree
Contact angle hysteresis of cylindrical drops on chemically heterogeneous striped surfaces does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Contact angle hysteresis of cylindrical drops on chemically heterogeneous striped surfaces, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Contact angle hysteresis of cylindrical drops on chemically heterogeneous striped surfaces will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-365396