Pregled bibliografske jedinice broj: 20361
Effects of urotropin on the chemical and microstructural properties of Fe-oxide powders prepared by the hydrolysis of aqueous FeCl3 solutions
Effects of urotropin on the chemical and microstructural properties of Fe-oxide powders prepared by the hydrolysis of aqueous FeCl3 solutions // Materials chemistry and physics, 52 (1998), 3; 214-220 doi:10.1016/S0254-0584(97)02032-4 (međunarodna recenzija, članak, znanstveni)
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Naslov
Effects of urotropin on the chemical and
microstructural properties of Fe-oxide powders
prepared by the hydrolysis of aqueous FeCl3
solutions
Autori
Šarić, Ankica ; Nomura, Kiyoshi ; Popović, Stanko ; Ljubešić, Nikola ; Musić, Svetozar
Izvornik
Materials chemistry and physics (0254-0584) 52
(1998), 3;
214-220
Vrsta, podvrsta i kategorija rada
Radovi u časopisima, članak, znanstveni
Ključne riječi
urotropin ; iron oxide powders ; hydrolysis ; chemical properties ; microstructure
Sažetak
The effects of urotropin on the chemical and microstructural properties of Fe-oxide powders, prepared by FeCl3 hydrolysis in aqueous solutions at 90oC, were investigated using X-ray powder diffraction, transmission electron microscopy, Fourier transform infrared spectroscopy and 57Fe Mössbauer spectroscopy. In the absence of urotropin, akaganéite (b-FeOOH) particles showed different morphologies, such as spindles, stars, X- and Y-shapes. After 5 hours of aging and for an initial 0.025 M urotropin concentration, acicular b-FeOOH particles (monodispersed) of decreased size were obtained. For the same time of aging and 0.25 M urotropin the particles were amorphous for X-ray diffraction, while 57Fe Mössbauer spectroscopy indicated that these particles were of very small dimensions (superparamagnetic) and probably of the FeOOH structure. The b-FeOOH formation at pH values significantly higher than pH~2 was explained by incomplete substitution of Cl ions in Fe(III)-hydroxy polymers with OH ions. The presence of specific adsorption of organic components on the solid hydrolytical products was not confirmed by FT-IR spectroscopy. After 7 days of aging and for an initial urotropin concentration up to 0.025 M, b-FeOOH was also obtained as a single phase, while for c ł 0.1 M urotropin mixtures of goethite (a-FeOOH) and hematite (a-Fe2O3) were formed. Phase transformations b-FeOOHŽ a-Fe2O3 and b-FeOOHŽ a- FeOOHŽ a-Fe2O3 were discussed in the sense of the dissolution/precipitation mechanism.
Izvorni jezik
Engleski
Znanstvena područja
Kemija
Citiraj ovu publikaciju:
Časopis indeksira:
- Current Contents Connect (CCC)
- Web of Science Core Collection (WoSCC)
- Science Citation Index Expanded (SCI-EXP)
- SCI-EXP, SSCI i/ili A&HCI
- Scopus
