Monitoring Entering and Spreading of Emulsion Droplets at an Expanding Air/Water Interface: A Novel Technique
| Autor: | Natalie E. Hotrum, T. van Vliet, G.A. van Aken, M.A. Cohen Stuart |
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| Rok vydání: | 2002 |
| Předmět: |
Entering coefficient
Whey protein Physics and Physical Chemistry of Foods Low protein Laboratorium voor Fysische chemie en Kolloïdkunde Whipping cream Whey protein isolate Surface pressure Spreading coefficient Biomaterials Surface tension Colloid and Surface Chemistry Equilibrium thermodynamics Thin film Physical Chemistry and Colloid Science VLAG Chromatography biology Chemistry Emulsion eye diseases Surfaces Coatings and Films Electronic Optical and Magnetic Materials Sodium caseinate Chemical engineering biology.protein Interfacial tension Air/water interface Protein adsorption |
| Zdroj: | Journal of Colloid and Interface Science 247 (2002) Journal of Colloid and Interface Science, 247, 125-131 |
| ISSN: | 0021-9797 |
| Popis: | The entering and spreading of emulsion droplets at quiescent and expanding air/water interfaces was studied using a new apparatus consisting of a modified Langmuir trough in which the air/water interface can be continuously expanded by means of rollers in the place of traditional barriers. When sodium caseinate and whey protein isolate-stabilized emulsion droplets were injected under the surface of sodium caseinate and whey protein isolate solutions, respectively, it appeared that the droplets entered the air/water interface only if the air/water surface pressure did not exceed a threshold value of approximately 15 mN/m. This condition was satisfied either under quiescent conditions for low protein concentrations or by continuous expansion of the interface at higher protein concentrations. According to equilibrium thermodynamics, entering of the droplets and the formation of lenses should occur for all the systems investigated, but this was not observed. At surface pressures higher than approximately 15 mN/m, immersed emulsion droplets were metastable. This is probably due to a kinetic barrier caused by the formation of a thin water film bounded by protein adsorption layers between the emulsion droplet and the air/water interface. |
| Databáze: | OpenAIRE |
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