17 research outputs found

    Synthesis of Zinc Ferrites in RF Thermal Plasma Reactor

    Get PDF
    Formation of nanosized zinc ferrite spinels was studied from iron- and zinc oxide powders and corresponding nitrate solutions, respectively in a radiofrequency thermal plasma reactor. From the viewpoint of applications, the research was motivated by the potential use of these materials in advanced magnetic devices on the one hand, and by their biomedical applications such as drug carriers or agents for cancer treatment by hyperthermia on the other. In this work effects of synthesis conditions on properties of products were studied in details. The products were characterised for chemical composition, phase conditions, particle size distribution, morphologies and saturation magnetisation. Most products exhibited ferrimagnetic behaviour. Correlations among domain- and particle sizes were also investigated. Conditions for the synthesis of nanosized, inverse zinc ferrites of high saturation magnetisation were established. It was proved that in thermal plasma conditions normal and inverse ferrites could be produced in a single step process

    Synthesis of Spinel Ferrites in Radiofrequency Thermal Plasma Reactor

    Get PDF
    Formation of nanosized zinc-ferrites and nickel-zinc ferrites from iron- and zinc oxide powders and corresponding nitrate solutions, respectively, was studied in RF thermal plasma conditions. The products were characterized for chemical composition, phase conditions, particle size distribution, morphologies and saturation magnetization. Effects of synthesis conditions on properties of products were studied in details

    A versatile characterization of poly(N-isopropylacrylamideco- N,N'-methylene-bis-acrylamide) hydrogels for composition, mechanical strength, and rheology

    Get PDF
    Poly(N-isopropylacrylamide-co-N,N"-methylene-bisacrylamide) (P(NIPAAm-co-MBA)) hydrogels were prepared in water using redox initiator. The copolymer composition at high conversion (> 95%) was determined indirectly by HPLC (high performance liquid chromatography) analysis of the leaching water and directly by solid state 13C CP MAS NMR (cross polarization magic angle spinning nuclear magnetic resonance) spectroscopy of the dried gels, and was found to be close to that of the feed. The effect of cross-linker (MBA) content in the copolymer was investigated in the concentration range of 1.1–9.1 mol% (R:90–10; R = mol NIPAAm/mol MBA) on the rheological behaviour and mechanical strength of the hydrogels. Both storage and loss modulus decreased with decreasing cross-linker content as revealed by dynamic rheometry. Gels R70 and R90 with very low cross-linker content (1.2–1.5 mol% MBA) have a very loose network structure, which is significantly different from those with higher cross-linker content manifesting in higher difference in storage modulus. The temperature dependence of the damping factor served the most accurate determination of the volume phase transition temperature, which was not affected by the cross-link density in the investigated range of MBA concentration. Gel R10 with highest cross-linker content (9.1 mol% MBA) behaves anomalously due to heterogeneity and the hindered conformation of the side chains of PNIPAAm

    Magyar TanĂ­tĂłkĂ©pzƑ 39 (1926) 2-3

    Get PDF
    Magyar TanĂ­tĂłkĂ©pzƑ A TanĂ­tĂłkĂ©pzƑ-intĂ©zeti TanĂĄrok OrszĂĄgos EgyesĂŒletĂ©nek közlönye 39. Ă©vfolyam, 2-3. szĂĄm Budapest, 1926. ĂĄprili

    Magyar TanĂ­tĂłkĂ©pzƑ 37 (1922) 4-8

    Get PDF
    Magyar TanĂ­tĂłkĂ©pzƑ A TanĂ­tĂłkĂ©pzƑ-intĂ©zeti TanĂĄrok OrszĂĄgos EgyesĂŒletĂ©nek közlönye 37. Ă©vfolyam, 4-8. szĂĄm Budapest, 1922. jĂșniu

    Magyar TanĂ­tĂłkĂ©pzƑ 27 (1912) 04

    Get PDF
    Magyar TanĂ­tĂłkĂ©pzƑ A TanĂ­tĂłkĂ©pzƑ-intĂ©zeti TanĂĄrok OrszĂĄgos EgyesĂŒletĂ©nek közlönye 27. Ă©vfolyam, Negyedik fĂŒzet Budapest, 1912. ĂĄprilis h

    Magyar TanĂ­tĂłkĂ©pzƑ 10 (1895) 09

    Get PDF
    Magyar TanĂ­tĂłkĂ©pzƑ A TanĂ­tĂłkĂ©pzƑ-intĂ©zeti TanĂĄrok OrszĂĄgos EgyesĂŒletĂ©nek közlönye 10. Ă©vfolyam, 09. fĂŒzet Budapest, 1895. november h
    corecore