Dye Aggregates as New Stabilizers for (Mini)emulsions
| Autor: | Susanne Sihler, Ulrich Ziener |
|---|---|
| Rok vydání: | 2017 |
| Předmět: |
02 engineering and technology
Surfaces and Interfaces Electrolyte 010402 general chemistry 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences 0104 chemical sciences Styrene chemistry.chemical_compound chemistry Chemical engineering Pulmonary surfactant Polymer chemistry Self-healing hydrogels Amphiphile Electrochemistry General Materials Science Absorption (chemistry) Sodium dodecyl sulfate 0210 nano-technology Spectroscopy Stabilizer (chemistry) |
| Zdroj: | Langmuir. 33:1239-1247 |
| ISSN: | 1520-5827 0743-7463 |
| Popis: | Water-soluble organic dyes such as fluorescein are widely used, mainly for coloration of, e.g., biological samples and groundwater tracing, and they are not obviously amphiphilic by molecular structure like surfactants. Here, we show that the dyes alone stabilize oil-in-water emulsions. Exemplarily, fluorescein is compared with the classical surfactant sodium dodecyl sulfate (SDS) by means of surface/interfacial tension, concentration of stabilizer and electrolyte, as well as pH. The principle can be extended to further classes of water-soluble dyes, which keep up with or exceed SDS by efficiency. Various organic liquids of different polarities can be employed and be polymerized in the case of styrene as disperse phase. Thus, surfactant free latex solely stabilized by water-soluble dyes is accessible. The emulsions can be destabilized by absorption of the dyes to hydrogels, and their complete removal is easily followed visually. The stabilization mechanisms are different for SDS and the dyes: The latter stabilize droplets not as monomers but by their aggregates as molecular scale Pickering stabilizers, which is a new concept of stabilization. |
| Databáze: | OpenAIRE |
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