Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection
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Book Part High-Performance Materials and Engineered Chemistry(CRC Press, 2018) Türk, Merve; Gümüş, Barış; Ustun, Fatma; Balköse, DevrimNano-sized nickel borate hydrate were precipitated from equimolar mixtures of dilute nickel nitrate and borax solutions at 25°C. Produced nickel borate samples were characterized by TGA, DSC, FTIR spectroscopy, X-ray diffraction, SEM, Elemental Analysis (EDX), Titration (nickel determination by EDTA, B<inf>2</inf>O<inf>3</inf> determination by NaOH), Particle Size Distribution, and Dehydration. The particles with 55 nm, 80 nm and 70 nm sizes were obtained for the cases without template, with span 60 and PEG 4000 in the reaction mixture respectively. The empirical formula of the vacuum dried precipitates were NiO.1.3B<inf>2</inf>O<inf>3</inf>.5.6 H<inf>2</inf>O, NiO.1.2B<inf>2</inf>O<inf>3</inf>.5.6 H<inf>2</inf>O and NiO.1.0B<inf>2</inf>O<inf>3</inf>.5.4 H<inf>2</inf>O for the cases without template, with span 60 and PEG 4000. The density of the nickel borate hydrates was around 2 g/ml and they had a color described by 157, 199 and 158 in RGB color scale. The nickel borate hydrates were amorphous in structure and no sharp peaks related to a crystal structure was present in their x-ray diffraction diagram. The effect of presence of span 60 and PEG 4000 were not significant on the particle size and chemical composition of the nanoparticles. © 2019 Elsevier B.V., All rights reserved.Article Citation - WoS: 8Citation - Scopus: 12A Microstructural Study of Surface Hydration on a Magnesia Refractory(Elsevier Ltd., 2010) Sütçü, Mücahit; Akkurt, Sedat; Okur, SalihHydration of the surface of a periclase refractory was studied in a controlled humidity atmosphere (92% relative humidity) at 26 °C for up to 92 h. The effect of humidity on the specimens was examined using a scanning probe microscope (SPM) and a scanning electron microscope (SEM), which showed that the degree of hydration was noticeably less in the intergranular bond phase compared to the periclase crystallites. The SPM study indicated significant growth of hydrates on the refractory grain surface. Growth rate of the hydrate layer was least on (0 0 1) orientation, higher for the (1 0 3) orientation, and highest for the (1 0 1) oriented grain. The rate of loss of refractory phases by hydration on a (1 0 1) oriented grain was 4.53 nm/h. This material loss may be insignificant for a bulk brick, but is a serious threat for a magnesia castable consisting of fine magnesia powder due to large surface area exposed to humidity or water itself. © 2010 Elsevier Ltd and Techna Group S.r.l. All rights reserved.