Investigations of Dissolving Mechanically Processed Quartz Grains

Steinike, U.; Hennig, H.‐P.; Richter‐Mendau, J.; Kretzschmar, U.

doi:10.1002/crat.2170171223

Cited by 14 publications

(8 citation statements)

References 4 publications

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“…From X-ray powder diffraction investigation it follows that only the disturbed partially cristalline part of quartz dissolves and reacts with y-Al,O, forming zeolite. The zeolite formation shows the same dependence on the quartz crystallinity as in ( BERNHARD et al ;STEINIKE et al 1982) cited quartz solubility after the mechanical activation under pressure and shear stress (in a vibration mill). Further experiments were made with precipitated amorphous SiO,.…”

Section: Zeolite Formationsupporting

confidence: 67%

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The Influence of Mechanical Activation of Quartz and Quartz/γ‐Al₂O₃ Mixtures on the Sodium A Zeolite Formation

Wutzler¹,

Klevzov

Steinike³

et al. 1991

Cryst. Res. Technol.

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It could be shown that the preparation of sodium A zeolite is possible by the reaction of quartz and y-A1,03 with NaOH-solution. The zeolite formation is dependent on the mechanical preliminary treatment of quartz. Only the partially crystalline part of quartz dissolves and reacts with Al,O, to form zeolite. The grinding of quartzly-Al,O, mixtures can in certain limits raise the zeolite formation but essentially only influences the kinetics of the zeolite formation.Es konnte gezeigt werden, daD eine Na-A-Zeolithbildung aus Quarz und y-Al,O, durch Umsetzung mit NaOH-Losung erfolgen kann. Die Zeolithbildung ist abhangig von der mechanischen Vorbehandlung des Quarzes. Es wird nur der partiell-kristalline Anteil des Quarzes aufgelost und mit y-Al,O, zu Zeolith umgesetzt. Eine Quarz/y-Al,O, Gemischmahlung kann die Zeolithbildung in bestimmten Grenzen erhohen, beeinflu& aber im wesentlichen nur die Kinetik der Zeolithbildung.

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Section: Zeolite Formationsupporting

confidence: 67%

“…The elementary step of the dissolution is influenced by lattice defects, e.g. bond breakings and deformation (WEYL;STEINIKE et al (1982)). Such defects could e.g.…”

Section: Introductionmentioning

confidence: 99%

The Influence of Mechanical Activation of Quartz and Quartz/γ‐Al₂O₃ Mixtures on the Sodium A Zeolite Formation

Wutzler¹,

Klevzov

Steinike³

et al. 1991

Cryst. Res. Technol.

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“…52,112 The perturbed external amorphous layer (known as Beilby layer), which often covers quartz particles, stems from such a process. [10][11][12]113 As a consequence, the surface of a crystalline silica particle with whom cells interact is not a perfect and regular crystalline face, but rather an almost amorphous and irregular one. A scanning electron microscopy (SEM) image showing conchoidal fractures on a microscopic quartz particle obtained by ball milling of larger crystals is reported in Figure 3b.…”

Section: Filling the Gaps In The Association Between Particle Surface...mentioning

confidence: 99%

“…Since ancient times, crystallinity was considered to be the prerequisite feature for silica pathogenicity, in spite of some reports on nonpathogenic quartz dusts ,, and the general notion among mineralogists that quartz particles generated by grinding yield irregular distributions of crystallographic surfaces, expose conchoidal fractures, , and are mostly covered by an amorphous layer. − The cells and tissue would have indeed been in direct contact with amorphous surfaces. Observing the occurrence of major occupations associated with silica exposure and related disasters (Table ), one feature emerges: in nearly all cases, crystalline silica (more often quartz, but also the other common polymorphs cristobalite and tridymite) was ground, crushed, or abraded.…”

Section: Variability Of Quartz Hazardmentioning

confidence: 99%

Unveiling the Variability of “Quartz Hazard” in Light of Recent Toxicological Findings

Pavan

Fubini

2016

Chem. Res. Toxicol.

101

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The variability of quartz hazard stands as one of the most puzzling issues in particle toxicology, notwithstanding the fact that silicosis, the most ancient occupational disease, was the very topic from which the study of the toxicity of particulates developed. Over the years, other adverse effects of silica particles (i.e., lung cancer and autoimmune diseases) were detected and described. However, a few gaps are still present in the physicochemical determinants and cellular pathways involved in the mechanisms of silica pathogenicity. In this perspective, we illustrate how pooling together studies in occupational health and nanotoxicology might fill such gaps, yielding a consistent picture of what imparts toxicity to a given silica source. Recent investigations have shown that crystallinity is not implied in the pathogenic process of silica per se, while patches of disorganized silanols at the surface of both crystalline and amorphous particles can promote membrane damage and inflammation, a process at the origin of silica-related diseases. Introducing these new findings into the accepted multistep model of silica pathogenicity, we obtain a picture of the chemical features of silica governing each cellular step in agreement with the outcomes of major previous studies. We ascribe the origin of the variability of silica hazard mainly to the distribution of various moieties at the particle surface, with silanols playing the major role. Toxicity turns out to be likely predictable by an ad hoc surface characterization. Tailored modifications of the surface can be envisaged to prepare safe materials or blunt toxicity in existing ones.

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“…The mechanical activation of silica particles can result in the formation of free radicals at the surface of the particles 1–5. The reactive free radicals may initiate covalent grafting of functional components onto the surface of the silica particles 6–9.…”

Section: Introductionmentioning

confidence: 99%

Production of filled hydrogels by mechanochemically induced polymerization

Damm

Mallembakam

Voronov

2010

J of Applied Polymer Sci

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Silica nanoparticles functionalized with polyvinylpyrrolidone (PVP) were obtained by the grinding/ mechanical activation of quartz or nonfunctionalized silica nanoparticles in a stirred media mill in the presence of 1-vinyl-2-pyrrolidone, as proven by Fourier transform infrared spectroscopy. The polymer layer thickness formed on the silica nanoparticles after 8 h of mechanical activation in the absence of polymerization initiators amounted to about 10 nm, as derived from shear rheology. The silica nanoparticles functionalized with the hydrophilic PVP by mechanochemical polymerization reaction were used as fillers for hydrogels based on poly(hydroxyethyl methacrylate) (polyHEMA). The water absorption, release properties, and mechanical properties of the polyHEMA-silica composites were measured as functions of the filler content and particle size of the filler. PolyHEMA samples containing 20 wt % of the functionalized silica particles exhibited a higher maximum water absorption than the unfilled polymer; this showed that the hydrophilic interface between the filler and the matrix improved the water absorption. The release of methylene blue from the poly-HEMA-silica composites was governed by diffusion and was almost unaffected by the silica particles. The values for the storage modulus and loss modulus of the poly-HEMA-silica composites increased with growing filler content. For constant filler content, the storage modulus increased with decreasing particle diameter of the filler; this showed that the reinforcing effect increased with the interface between the filler particles and the matrix polymer.

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Investigations of Dissolving Mechanically Processed Quartz Grains

Cited by 14 publications

References 4 publications

The Influence of Mechanical Activation of Quartz and Quartz/γ‐Al₂O₃ Mixtures on the Sodium A Zeolite Formation

The Influence of Mechanical Activation of Quartz and Quartz/γ‐Al₂O₃ Mixtures on the Sodium A Zeolite Formation

Unveiling the Variability of “Quartz Hazard” in Light of Recent Toxicological Findings

Production of filled hydrogels by mechanochemically induced polymerization

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Investigations of Dissolving Mechanically Processed Quartz Grains

Cited by 14 publications

References 4 publications

The Influence of Mechanical Activation of Quartz and Quartz/γ‐Al2O3 Mixtures on the Sodium A Zeolite Formation

The Influence of Mechanical Activation of Quartz and Quartz/γ‐Al2O3 Mixtures on the Sodium A Zeolite Formation

Unveiling the Variability of “Quartz Hazard” in Light of Recent Toxicological Findings

Production of filled hydrogels by mechanochemically induced polymerization

Contact Info

Product

Resources

About

The Influence of Mechanical Activation of Quartz and Quartz/γ‐Al₂O₃ Mixtures on the Sodium A Zeolite Formation

The Influence of Mechanical Activation of Quartz and Quartz/γ‐Al₂O₃ Mixtures on the Sodium A Zeolite Formation