Bulletin of the American Physical Society
64th Annual Meeting of the APS Division of Fluid Dynamics
Volume 56, Number 18
Sunday–Tuesday, November 20–22, 2011; Baltimore, Maryland
Session J29: Invited Session: Roughness-based Superhydrophobic Surfaces: Fundamentals and Future Directions |
Hide Abstracts |
Chair: Gareth McKinley, Massachusetts Institute of Technology Room: Ballroom III-IV |
Monday, November 21, 2011 2:00PM - 2:35PM |
J29.00001: Roughness-based Superhydrophobic Surfaces: Fundamentals and Future Directions Invited Speaker: Neelesh Patankar Superhydrophobicity of rough surfaces has attracted global interest through the past decade. There are naturally occurring instances of such surfaces, e.g., lotus leaves, which led to the popular term ``lotus effect.'' Numerous applications in wide ranging areas such as drag reduction, self-cleaning, heat exchangers, energy conversion, condensation, anti-icing, textile, desalination, etc., are being explored by researchers worldwide. The signature configuration for superhydrophobicity has been ``bead-like'' drops on rough surfaces that roll-off easily. This becomes possible if the liquid does not impale the roughness grooves, and if the contact angle hysteresis is low. Finding appropriate surface roughness is therefore necessary. A thermodynamic framework to enable analysis of this problem will be presented. It will be noted that the success of rough superhydrophobic substrates relies on the presence of gas pockets in the roughness grooves underneath the liquid. These gas pockets could be those of air from the surrounding environment. Current design strategies rely on the availability of air. However, if the rough substrates are fully submerged in the liquid then the trapped air in the roughness grooves may not be sustained. A design approach based on sustaining a vapor phase of the liquid itself in the roughness grooves, instead of relying on the presence of air, will be presented. The resulting surfaces, referred to as vapor stabilizing substrates, are deemed to be robust against wetting transition even if no air is present. Applications of this approach include low drag surfaces, nucleate boiling at dramatically low superheats, among others. The concept can be generalized to other transitions on the phase diagram, thus enabling the design of rough surfaces for phase manipulation in general. [Preview Abstract] |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700