Dynamic elasticity of films formed by poly(N-isopropylacrylamide) microparticles on a water surface
| Autor: | G. S. Rybnikova, Kirill A. Timoshen, Boris A. Noskov, A. A. Novikova, Ivan M. Zorin, Alexander V. Akentiev |
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| Rok vydání: | 2017 |
| Předmět: |
chemistry.chemical_classification
Materials science Relaxation (NMR) Analytical chemistry 02 engineering and technology Surfaces and Interfaces Polymer 010402 general chemistry 021001 nanoscience & nanotechnology 01 natural sciences 0104 chemical sciences chemistry.chemical_compound Colloid and Surface Chemistry chemistry Metastability Monolayer Poly(N-isopropylacrylamide) Compression (geology) Physical and Theoretical Chemistry Microparticle 0210 nano-technology Dispersion (chemistry) |
| Zdroj: | Colloid Journal. 79:571-576 |
| ISSN: | 1608-3067 1061-933X |
| Popis: | Surface dilatational dynamic elasticity e of films formed by cross-linked poly(N-isopropylacrylamide) microparticles on a water/air interface has been determined as a function of polymer surface concentration Γ. The experimental dependences exhibit two maxima of e at surface pressures π of nearly 6 and 35 mN/m. In the region of the second maximum, the pattern of the dependence is governed by a method used to vary Γ. At π > 25 mN/m, film compression leads to the formation of a metastable monolayer, while the gradual addition of a microparticle dispersion results in the establishment of equilibrium between the monolayer and surface aggregates. In the region of π values corresponding to the second maximum of e, slow relaxation processes with a characteristic time substantially longer than 10 s occur in the system. At π > 35 mN/m, the film collapses due to the displacement of microgel particles from the water surface. |
| Databáze: | OpenAIRE |
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