Crystallization and Thermal Stability of the P-Doped Basaltic Glass Fibers

The present research focuses on the influence of phosphorus oxide additives on the structure and thermal properties of the basalt glasses, produced in the form of fibers, i.e. at very high quenching speed. Basaltic glass fibers with various P2O5 contents were produced in two stages. In the first stage, the bulk glasses were prepared by adding variable amounts of (NH4)4P2O7 to milled natural andesitic basalt in order to obtain samples containing 2, 4, and 6 wt % P2O5. In the second stage, the glass fibers were obtained using a laboratory-scale system. Basalt glass fibers were characterized by Raman spectroscopy to obtain information on the structure of the obtained fibers, and by DSC-TG and XRD analyses to determine the change in crystallization mechanism of basaltic fibers. The hydrostatic weighing was used for the determination of glasses density. An increase in the content of P2O5 to 6 wt % leads to a decrease in the density of glass fibers due to the polymerizing effect of phosphorus oxide. The obtained X-ray diffraction patterns indicate that all samples are X-ray amorphous. The Raman results show that the decrease in the intensity of the line corresponding to vibrations of the structural units Q2 (about 920 cm–1) with respect to the line corresponding to Q3 (about 1125 cm–1) is related to an increase of P2O5 content. This also indicates the increase in polymerization degree of glass structure. DSC and XRD data also found out the change of phase transformations order with an increase of phosphorus oxide. The crystallization in natural and modified basalt glass fibers begins with spontaneous spinel-like phase formations that become nucleation sites for the precipitation of monoclinic pyroxene as a major phase. With an increase in the P2O5 content, there is a tendency to a decrease in the pyroxene at higher temperature, as a result of which, the hematite crystallizes at lower temperatures. That is associated with the activation of liquation processes, accompanied by the formation of amorphous phases with different viscosities with an increase in the concentration of P2O5. In conclusion, all the obtained data indicate the prospect of using the proposed approach to obtain basalt glass fibers with enhanced thermal and mechanical stability.

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Freshwater Alteration of Basaltic Glass, Hanauma Bay, Oahu, Hawaii: A Natural Analogue for the Alteration of Borosilicate Glass in Fresh Water

MRS Proceedings ◽

10.1557/proc-127-49 ◽

1988 ◽

Vol 127 ◽

Cited By ~ 6

Author(s):

Rachel Cowan ◽

Rodney C. Ewing

Keyword(s):

Fresh Water ◽

Microprobe Analysis ◽

Electron Microprobe Analysis ◽

Vertical Section ◽

Basaltic Glass ◽

Natural Analogue ◽

X Ray Diffraction ◽

Volume Percent ◽

X Ray ◽

Basalt Glasses

ABSTRACTAlteration (fresh water) products (palagonite and zeolites) of a 12, 000–28, 000 year old basaltic glass from Hanauma Bay, Hawaii, were examined by electron microprobe analysis, scanning electron microscopy, and X-ray diffraction analysis. The palagonite, 0 to 300 microns thick, is depleted in Si, Al, Ca, Na, and K and enriched in Ti and Fe. Ca-rich zeolites are associated with palagonite that is slightly more depleted in Ca; all samples contain zeolites and low Al-palagonite. The rate of palagonitization (0.002–0.005 volume percent/year) is less than the experimentally predicted rate for basalt glasses due to the episodic presence of the percolating groundwater. The Si/AI ratio of the zeolites decreases with increasing pH of the groundwater as it passes through the vertical section. Zeolite paragenesis is (first to last): analcime (NaAlSi2O 6·H2O), phillipsite [(1/2 Ca, Na, K)(Al3Si5O16).6H2O], chabazite (CaAl2SiO16.6H2O).

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Rapid Thermal Oxidation for Passivation of Porous Silicon

MRS Proceedings ◽

10.1557/proc-342-91 ◽

1994 ◽

Vol 342 ◽

Cited By ~ 6

Author(s):

I. BÁrsony ◽

J.G.E. Klappe ◽

É. Vázsonyi ◽

T. Lohner ◽

M. Fried

Keyword(s):

Porous Silicon ◽

Mechanical Stability ◽

Porous Substrate ◽

X Ray Diffraction ◽

X Ray ◽

Si Substrates ◽

Tetragonal Lattice ◽

Optical Heating ◽

Vertical Inhomogeneity ◽

Highly Porous

ABSTRACTChemical and mechanical stability of porous silicon layers (PSL) is the prerequisite of any active (luminescent) or passive (e.g. porous substrate) integrated applications. In this work X-ray diffraction (XRD) was used to analyze quantitatively the strain distribution obtained in different morphology PSL that were prepared on (100) p and p+Si substrates. Tetragonal lattice constant distortion can be as high as 1.4% in highly porous “as-prepared” samples. Incoherent optical heating RTO is governed by the absorption in the oxidized specimen. PSL show vertical inhomogeneity according to interpretation of spectroscopic ellipsometry (SE) data. Oxygen incorporation during RTO is controlled by specific surface (in p+ proportional, in p inversely proportional with porosity), while the developing compressive stress depends on pore size, and decreases with porosity in both morphologies.

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Scattering and phase-contrast X-ray methods reveal damage to glass fibers in endodontic posts following dental bur trimming

Dental Materials ◽

10.1016/j.dental.2020.10.018 ◽

2020 ◽

Author(s):

Ana Prates Soares ◽

Daniel Baum ◽

Bernhard Hesse ◽

Andreas Kupsch ◽

Bernd R. Müller ◽

...

Keyword(s):

Phase Contrast ◽

Glass Fibers ◽

X Ray ◽

Ray Methods

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Volcanic Glass as a Natural Analog for Borosilicate Waste Glass

MRS Proceedings ◽

10.1557/proc-333-605 ◽

1993 ◽

Vol 333 ◽

Cited By ~ 3

Author(s):

Maury E. Morgenstein ◽

Don L. Shettel

Keyword(s):

Silica Glass ◽

Glass Structure ◽

Volcanic Glass ◽

Waste Glass ◽

Tensile Failure ◽

Tensile Fracture ◽

Failure Behavior ◽

Basaltic Glass ◽

Glass Waste ◽

Natural Analog

ABSTRACTObsidian and basaltic glass are opposite end-members of natural volcanic glass compositions. Syngenetic and diagenetic tensile failure in basaltic glass (low silica glass) is pervasive and provides abundant alteration fronts deep into the glass structure. Perlitic fracturing in obsidian (high silica glass) limits the alteration zones to an “onion skin” geometry. Borosilicate waste glass behaves similarly to the natural analog of basaltic glass (sideromelane).During geologic time, established and tensile fracture networks form glass cells (a three-dimensional reticulated pattern) where the production of new fracture surfaces increases through time by geometric progression. This suggests that borosilicate glass monoliths will eventually become rubble. Rates of reaction appear to double for every 12C° of temperature increase. Published leach rates suggest that the entire inventory of certain radionuclides may be released during the 10,000 year regulatory time period. Steam alteration prior to liquid attack combined with pervasive deep tensile failure behavior may suggest that the glass waste form is not license defensible without a metallic- and/or ceramic-type composite barrier as an overpack.

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X-Ray Study of Glass Fibers

Journal of the American Ceramic Society ◽

10.1111/j.1151-2916.1953.tb12885.x ◽

1953 ◽

Vol 36 (9) ◽

pp. 294-298 ◽

Cited By ~ 9

Author(s):

BHUPATI KUMAR BANERJEE

Keyword(s):

Glass Fibers ◽

X Ray

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Experimental seawater-basaltic glass interaction at 50°C: Study of early developed phases by electron microscopy and X-ray photoelectron spectrometry

Geochimica et Cosmochimica Acta ◽

10.1016/0016-7037(83)90260-0 ◽

1983 ◽

Vol 47 (3) ◽

pp. 377-387 ◽

Cited By ~ 70

Author(s):

J.L. Crovisier ◽

J.H. Thomassin ◽

T. Juteau ◽

J.P. Eberhart ◽

J.C. Touray ◽

...

Keyword(s):

Electron Microscopy ◽

Basaltic Glass ◽

X Ray

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Compressibility Studies of Zirconium Based Metal-Organic Frameworks

Acta Crystallographica Section A Foundations and Advances ◽

10.1107/s2053273314098428 ◽

2014 ◽

Vol 70 (a1) ◽

pp. C157-C157

Author(s):

Claire Hobday ◽

Stephen Moggach ◽

Carole Morrison ◽

Tina Duren ◽

Ross Forgan

Keyword(s):

High Pressure ◽

Mechanical Stability ◽

Metal Organic Frameworks ◽

External Pressure ◽

X Ray Diffraction ◽

X Ray ◽

X Ray Crystallography ◽

Pressure Medium ◽

Metal Organic ◽

University Of Oslo

Metal-organic frameworks (MOFs) are a well-studied class of porous materials with the potential to be used in many applications such as gas storage and catalysis.[1] UiO-67 (UiO = University of Oslo), a MOF built from zirconium oxide units connected with 4,4-biphenyldicarboxylate (BDC) linkers, forms a face centred cubic structure. Zirconium has a high affinity towards oxygen ligands making these bridges very strong, resulting in UiO-based MOFs having high chemical and thermal stability compared to other MOF structures. Moreover, UiO-67 has become popular in engineering studies due to its high mechanical stability.[2] Using high pressure x-ray crystallography we can exert MOFs to GPa pressures, experimentally exploring the mechanical stability of MOFs to external pressure. By immersing the crystal in a hydrostatic medium, pressure is applied evenly to the crystal. On surrounding a porous MOF with a hydrostatic medium composed of small molecules (e.g. methanol), the medium can penetrate the MOF, resulting in medium-dependant compression. On compressing MOF-5 (Zn4O(BDC)3) using diethylformamide as a penetrating medium, the framework was shown to have an increased resistance to compression, becoming amorphous several orders of magnitude higher in pressure than observed on grinding the sample.[3] Here we present a high-pressure x-ray diffraction study on the UiO-based MOF UiO-67, and several new synthesised derivatives built from same metal node but with altered organic linkers, allowing us to study in a systematic way, the mechanical stability of the MOF, and its pressure dependence on both the linker, and pressure medium.

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The Use of Tailings to Make Glass as an Alternative for Sustainable Environmental Remediation: The Case of Osor, Catalonia, Spain

Minerals ◽

10.3390/min10090819 ◽

2020 ◽

Vol 10 (9) ◽

pp. 819

Author(s):

Pura Alfonso ◽

Oriol Tomasa ◽

Luis Miguel Domenech ◽

Maite Garcia-Valles ◽

Salvador Martinez ◽

...

Keyword(s):

Environmental Remediation ◽

Toxic Elements ◽

Glass Structure ◽

Glass Production ◽

Potentially Toxic Elements ◽

Raw Material ◽

Waste Materials ◽

X Ray Diffraction ◽

X Ray ◽

Melting Temperatures

Tailings from the Osor fluorite mines release large amounts of potentially toxic elements into the environment. This work is a proposal to remove these waste materials and use them as a raw material in the manufacture of glass. The chemical composition of the tailings was determined by X-ray fluorescence and the mineralogy by X-ray diffraction. Waste materials have SiO2, Al2O3 and CaO contents suitable for a glass production, but Na as NaCO3 has to be added. Two glass formulations, with 80–90% of the residue and 10–20% Na2CO3, have been produced. The crystallization temperatures, obtained by differential thermal analysis, were 875 and 901 °C, and the melting temperatures were 1220 and 1215 °C for the G80-20 and G90-10 glasses, respectively. The transition temperatures of glass were 637 and 628 °C. The crystalline phases formed in the thermal treatment to produce devitrification were nepheline, plagioclase and diopside in the G80-20 glass, and plagioclase and akermanite-gehlenite in the G90-10 glass. The temperatures for the fixed viscosity points, the working temperatures and the coefficient of expansion were obtained. The chemical stability of the glass was tested and results indicate that the potentially toxic elements of the tailings were incorporated into the glass structure.

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