Water microdroplets on molecularly tailored surfaces: correlation between wetting hysteresis and evaporation mode switching
| Autor: | Dinah M. Soolaman, Hua-Zhong Yu |
|---|---|
| Rok vydání: | 2006 |
| Předmět: |
Materials science
Time Factors Surface Properties Analytical chemistry Evaporation Water Surface finish Models Theoretical Microscopy Atomic Force Silicon Dioxide Surfaces Coatings and Films Contact angle Hysteresis Kinetics Wetting transition visual_art Materials Chemistry visual_art.visual_art_medium Wetting Physical and Theoretical Chemistry Polycarbonate Composite material Contact area Polytetrafluoroethylene Physics::Atmospheric and Oceanic Physics |
| Zdroj: | The journal of physical chemistry. B. 109(38) |
| ISSN: | 1520-6106 |
| Popis: | The evaporation of water microdroplets from solid surfaces was studied using digital contact angle analysis techniques. An inclusive trend for the evaporation process, that is, a switch from the initial constant contact area to the subsequent constant contact angle mode was observed for all surfaces examined, including mixed self-assembled monolayers (SAMs) on gold and "conventional" surfaces such as silicon wafers, polycarbonate, and Teflon. More importantly, it has been shown that the change in contact angle during the evaporation process (i.e., evaporation hysteresis, delta theta(evap), the difference between the initial and "equilibrated" contact angle) correlates well with the wetting hysteresis determined directly (i.e., measuring the advancing and receding contact angles on these surfaces by changing the drop volume). The comparison between mixed SAM surfaces and conventional solids revealed that the evaporation/wetting hysteresis is dominated by the roughness (from nanometer to micrometer scale) rather than the chemical heterogeneity of the surface. The evaporation rates of water microdroplets on these surfaces were also monitored and modeled. |
| Databáze: | OpenAIRE |
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