Film Trapping Technique: Precise Method for Three-Phase Contact Angle Determination of Solid and Fluid Particles of Micrometer Size
| Autor: | Ivan B. Ivanov, Roumiana Dimova, Asen Hadjiiski, Nikolai D. Denkov, Rajendra P. Borwankar |
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| Rok vydání: | 1996 |
| Předmět: |
Laplace's equation
Capillary pressure Capillary condensation business.industry Chemistry Surfaces and Interfaces Condensed Matter Physics law.invention Physics::Fluid Dynamics Contact angle Optics law Oil droplet Micrometer Electrochemistry Meniscus Particle General Materials Science Composite material business Spectroscopy |
| Zdroj: | Langmuir. 12:6665-6675 |
| ISSN: | 1520-5827 0743-7463 |
| Popis: | A novel method for determination of the three-phase contact angle at the surface of a micrometer-sized particle (latex sphere, oil droplet, or biological cell) is described. The particle is entrapped within a liquid filmofequilibriumthicknesssmallerthantheparticlediameter. Thusaliquidmeniscus(alayerofuneven thickness) is formed around the particle. When observed in reflected monochromatic light, this meniscus appearsasaninterferencepatternofconcentricbrightanddarkfringes. Fromtheradiioftheinterference fringes, one can restore the meniscus shape by using the solution of the Laplace equation of capillarity. In this way the three-phase contact angle of the particle and the capillary pressure can be determined. We demonstrate the applicability of our method to latex spheres from several batch samples (between 1 and 7 Im in diameter) and to oil droplets, stabilized by adsorbed protein layer. The numerical procedures used for contact angle determination are described, and illustrative results are presented and discussed. |
| Databáze: | OpenAIRE |
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