Sol–gel method as a way of carbonyl iron powder surface modification for interaction improvement

Journal Article · Sun Mar 15 00:00:00 EDT 2015 · Journal of Solid State Chemistry

DOI:https://doi.org/10.1016/J.JSSC.2015.03.002· OSTI ID:22475658

Kolman, K.; Pigłowski, J. ^[1]; Kaleta, J. ^[2]

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1. Polymer Engineering and Technology Division, W-3, Wrocław University of Technology, Smoluchowskiego 25, 50 370 Wrocław (Poland)
2. Department of Mechanics, Materials Science and Engineering, W-10, Wrocław University of Technology, Smoluchowskiego 25, 50-370 Wrocław (Poland)

This article presents a method for modification of carbonyl iron particles’ surface (CIP), (d{sub 50}=4–9 µm) by silica coatings obtained using the sol–gel method. Reaction parameters were determined to obtain dry magnetic powder with homogeneous silica coatings without further processing and without any by-product in the solid or liquid phase. This approach is new among the commonly used methods of silica coating of iron particles. No attempt has been made to cover a carbonyl iron surface by silica in a waste-free method, up to date. In the current work two different silica core/shell structures were made by the sol–gel process, based on different silica precursors: tetraethoxy-silane (TEOS) and tetramethoxy-silane (TMOS). The dependence between the synthesis procedure and thickness of silica shell covering carbonyl iron particles has been described. Surface morphology of the modified magnetic particles and the coating thickness were characterized with the use of scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Determination of the physicochemical structure of the obtained materials was performed by the energy-dispersive X-ray spectroscope (EDS), and the infrared technique (IR). The surface composition was analyzed using X-ray photoelectron spectroscopy (XPS). Additionally, distribution of particle size was measured using light microscopy. The new, efficient process of covering micro-size CIP with a nanometric silica layer was shown. Results of a performed analysis confirm the effectiveness of the presented method. - Highlights: • Proper covering CIP by sol–gel silica layer avoids agglomeration. • A new solid waste-free method of CIP coating is proposed. • Examination of the properties of modified CIP in depends on washing process. • Coatings on CIP particles doesn’t change the magnetic properties of particles.

• OSTI ID: 22475658
• Journal Information: Journal of Solid State Chemistry, Vol. 226; Other Information: Copyright (c) 2015 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC
ORGANIC
PHYSICAL AND ANALYTICAL CHEMISTRY
AGGLOMERATION
CARBONYLS
COATINGS
IRON
LAYERS
MAGNETIC PROPERTIES
MORPHOLOGY
NANOSTRUCTURES
PARTICLE SIZE
PARTICLES
POWDERS
SCANNING ELECTRON MICROSCOPY
SILANES
SILICA
SOL-GEL PROCESS
SURFACES
SYNTHESIS
TRANSMISSION ELECTRON MICROSCOPY
VISIBLE RADIATION
X-RAY PHOTOELECTRON SPECTROSCOPY