Heating of polyacrylamide ferrogel by alternating magnetic field
| Autor: | O. M. Samatov, Ekaterina A. Mikhnevich, Alexander P. Safronov, I. S. Tyukova, I.V. Beketov |
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| Rok vydání: | 2016 |
| Předmět: |
010302 applied physics
Ferrofluid Materials science Orders of magnitude (temperature) Maghemite Nanoparticle 02 engineering and technology Adhesion engineering.material 021001 nanoscience & nanotechnology Condensed Matter Physics 01 natural sciences Electronic Optical and Magnetic Materials Magnetic field Dipole Nuclear magnetic resonance Dynamic light scattering Chemical physics 0103 physical sciences engineering 0210 nano-technology |
| Zdroj: | Journal of Magnetism and Magnetic Materials. 415:24-29 |
| ISSN: | 0304-8853 |
| Popis: | Ferrogel based on polacryamide network with embedded maghemite nanoparticles with mean number average particle diameter 12 nm was synthesized by radical polymerization in water-based ferrofluid. The network structure of ferrogel was characterized by Flory–Rehner theory and it was shown that the embedded particles were substantially larger than the mesh size. It prevented the translational movement of particles in the ferrogel. The immobilization of particles was confirmed by dynamic light scattering. The adhesion of macromolecular chains to the particles was determined by calorimetry using thermochemical cycle. The enthalpy of interfacial adhesion was found several orders of magnitude higher than the energy of dipoles in typically applied magnetic fields. Despite the differenve in the mobility of particles in ferrofluid and ferrogel the comparative study of their heating in alternating magnetic field, however, revealed their close similarity. In both cases it was goverened by superposing of Neel and Brownian relaxation mechanisms. |
| Databáze: | OpenAIRE |
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