Synthesis and Characterization of Synthetic F-Mica Containing Glass-Ceramics in the System SiO2·Al2O3·B2O3·CaO·MgO·Li2O·(K,Na)2O·F

2004 ◽  
Vol 19 (4) ◽  
pp. 1234-1242 ◽  
Author(s):  
D.U. Tulyaganov ◽  
S. Agathopoulos ◽  
H.R. Fernandes ◽  
J.M.F. Ferreira
Keyword(s):  
Crystallization Temperature ◽  
Crystallization Process ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
Synthesis And Characterization ◽  
Na Ions ◽  
Anions And Cations ◽  
And Chemical Properties

Ions of Li, Na, K, and B were incorporated in Ca-mica, CaMg3Al2Si2O10F2. The crystallization process and the properties of the resulting glass-ceramics were experimentally determined, and the role of the anions and cations is discussed. According to the results, Li, K, and Na ions strongly affected the formation of the crystalline phases. Until 900 °C, pargasite and F-cannilloite amphiboles and KLi-mica were predominately crystallized. The two amphiboles are dissociated, yielding stable forsterite at 900 °C and Ca-mica and spinel at 950 °C. KLi-mica showed remarkable stability and growth within the investigated temperature range, until 1000 °C. The optimum crystallization temperature for the investigated glass-ceramics is between800 °C and 900 °C. The produced glass-ceramics exhibited capability for easy bulk crystallization, high whiteness, translucency, and mechanical and chemical properties suitable for several applications.

Non-Crystallographic Nanopores in Single Crystals: A New Approach in Nanomaterials Chemistry

2004 ◽  
Vol 443-444 ◽  
pp. 217-222
Author(s):  
Claus J.H. Jacobsen ◽  
Iver Schmidt ◽  
Michael Brorson ◽  
Astrid Boisen ◽  
Thomas W. Hansen ◽  
...  
Keyword(s):  
Single Crystals ◽  
Chemical Properties ◽  
Metal Sulfide ◽  
Building Blocks ◽  
New Approach ◽  
New Family ◽  
Physical And Chemical ◽  
And Chemical Properties

Nanomaterials are the building blocks of nanotechnology. Recently, nanotube materials have attracted considerable attention due to their unique physical and chemical properties. Here we discuss how nanotubes can be used as templates for preparation of a new family of materials, the nanoporous single crystals, and for the preparation of metal sulfide nanotube materials. Today, the characterization of these materials depends heavily on electron microscopy. However, as rational synthesis schemes are becoming available, more well-defined, homogeneous nanotube samples will be produced and the role of diffraction techniques may increase.

scholarly journals Synthesis and Characterization of Some New Tropylidene Derivatives and Studying their Biological Activities

2021 ◽  
pp. 3307-3322
Author(s):  
Muath Jabbar Tarfa Al-Abbasee ◽  
Ahmood khalaf Jebur ◽  
Afraa Sabir Shihab
Keyword(s):  
Melting Point ◽  
Biological Activities ◽  
Chemical Properties ◽  
Synthesis And Characterization ◽  
Antibacterial And Antifungal Activities ◽  
Ft Ir ◽  
Antibacterial And Antifungal ◽  
And Chemical Properties

    Some new tropylidene derivatives were prepared in this work and their in vitro antibacterial and antifungal activities were studied. All the prepared compounds were characterized by their physical properties, such as melting point and color, and chemical properties, using the techniques of FT-IR, 1H-NMR and 13C-NMR.

The Nature of S-N Bonding in Sulfonamides and Related Compounds: Insights into π-Bonding Contributions from Sulfur K-Edge XAS

2020 ◽  
Author(s):  
Tulin Okbinoglu ◽  
Pierre Kennepohl
Keyword(s):  
Density Functional ◽  
Chemical Properties ◽  
Functional Theory ◽  
Rotational Barriers ◽  
Td Dft ◽  
Nitrogen Bonds ◽  
X Ray Absorption ◽  
Related Compounds ◽  
And Chemical Properties

Molecules containing sulfur-nitrogen bonds, like sulfonamides, have long been of interest due to their many uses and chemical properties. Understanding the factors that cause sulfonamide reactivity is important, yet their continues to be controversy regarding the relevance of S-N π bonding in describing these species. In this paper, we use sulfur K-edge x-ray absorption spectroscopy (XAS) in conjunction with density functional theory (DFT) to explore the role of S<sub>3p</sub> contributions to π-bonding in sulfonamides, sulfinamides and sulfenamides. We explore the nature of electron distribution of the sulfur atom and its nearest neighbors and extend the scope to explore the effects on rotational barriers along the sulfur-nitrogen axis. The experimental XAS data together with TD-DFT calculations confirm that sulfonamides, and the other sulfinated amides in this series, have essentially no S-N π bonding involving S<sub>3p</sub> contributions and that electron repulsion and is the dominant force that affect rotational barriers.

Synthesis and Characterization of Nanocrystalline ZnO Powders by a Direct Thermal Decomposition Route Using Zinc Nitrate Hexahydrate

2013 ◽  
Vol 770 ◽  
pp. 68-71 ◽  
Author(s):  
Supphadate Sujinnapram ◽  
Uraiphorn Termsuk ◽  
Atcharawan Charoentam ◽  
Sutthipoj Sutthana
Keyword(s):  
Thermal Decomposition ◽  
Crystallization Temperature ◽  
Zinc Nitrate ◽  
Zinc Nitrate Hexahydrate ◽  
Absorption Peak ◽  
Synthesis And Characterization ◽  
Nitrate Hexahydrate ◽  
Different Temperatures ◽  
Zno Powders

The nanocrystalline ZnO powders were synthesized by a direct thermal decomposition using zinc nitrate hexahydrate as starting materials. The precursor was characterized by TG-DTA to determine the thermal decomposition and crystallization temperature which was found to be at 325 oC. The precursors were calcined at different temperatures of 400, 500, and 600°C for 4 h. The structure of the prepared samples was studied by XRD, confirming the formation of wurtzite structure. The synthesized powders exhibited the UV absorption below 400 nm (3.10 eV) with a well defined absorption peak at around 285 nm (4.35 eV). The estimated direct bandgaps were obtained to be 3.19, 3.16, and 3.14 eV for the ZnO samples thermally decomposed at 400, 500, and 600°C, respectively.

scholarly journals Eco-Compatible Construction Materials Containing Ceramic Sludge and Packaging Glass Cullet

2021 ◽  
Vol 11 (8) ◽  
pp. 3545
Author(s):  
Fernanda Andreola ◽  
Isabella Lancellotti ◽  
Paolo Pozzi ◽  
Luisa Barbieri
Keyword(s):  
Raw Materials ◽  
Construction Materials ◽  
Treatment Plant ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
Linear Shrinkage ◽  
Glass Cullet ◽  
Commercial Glass ◽  
Packaging Glass ◽  
And Chemical Properties

This research reports results of eco-compatible building material obtained without natural raw materials. A mixture of sludge from a ceramic wastewater treatment plant and glass cullet from the urban collection was used to obtain high sintered products suitable to be used as covering floor/wall tiles in buildings. The fired samples were tested by water absorption, linear shrinkage, apparent density, and mechanical and chemical properties. Satisfactory results were achieved from densification properties and SEM/XRD analyses showed a compact polycrystalline microstructure with albite and wollastonite embedded in the glassy phase, similar to other commercial glass-ceramics. Besides, the products were obtained with a reduction of 200 °C with respect to the firing temperatures of commercial ones. Additionally, the realized materials were undergone to leaching test following Italian regulation to evaluate the mobility of hazardous ions present into the sludge. The data obtained verified that after thermal treatment the heavy metals were immobilized into the ceramic matrix without further environmental impact for the product use. The results of the research confirm that this valorization of matter using only residues produces glass ceramics high sintered suitable to be used as tile with technological properties similar or higher than commercial ones.

Thermal and chemical properties of TiO2-SiO2 porous glass-ceramics

1987 ◽  
Vol 22 (7) ◽  
pp. 2583-2588 ◽  
Author(s):  
Toshinori Kokubu ◽  
Masayuki Yamane
Keyword(s):  
Porous Glass ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
And Chemical Properties
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