Chemical Engineering / Kimya Mühendisliği
Permanent URI for this collectionhttps://hdl.handle.net/11147/14
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Conference Object Citation - WoS: 24Effect of pH and Hydration on the Normal and Lateral Interaction Forces Between Alumina Surfaces(2006) Polat, Mehmet; Sato, Kimiyasu; Nagaoka, Takaaki; Watari, KojiNormal and lateral interaction forces between alumina surfaces were measured using Atomic Force Microscopy-Colloid Probe Method at different pH. The normal force curves exhibit a well-defined repulsive barrier and an attractive minimum at acidic pH and the DLVO theory shows excellent agreement with the data. The normal forces are always repulsive at basic pH and the theory fails to represent the measurements. Lateral forces are almost an order of magnitude smaller in the basic solutions. These differences, which have important implications in the study of stability and rheology, are attributed to the hydration of the alumina surface at basic pH. © 2013 Elsevier B.V., All rights reserved.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.