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Is simulated ‘‘amorphous’’ silica really amorphous?
AIP Conference Proceedings, 1994We have carried out extensive molecular dynamics simulations for the pressure induced amorphization of quartz by means of a classical force‐field model. In agreement with earlier simulations, we find that a phase transition occurs within the experimental pressure range of the amorphization.
N. Binggeli, James R. Chelikowsky
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Preparation of amorphous silica
The Canadian Journal of Chemical Engineering, 1971AbstractAmorphous silica having reinforcing properties for styrene butadiene rubber (SBR) was obtained by contacting silica aquagel seed, containing 1‐3% SiO2 by weight, with a freshly prepared silica sol. Reinforcing by the isolated silica was greatly affected by the pH of the aquagel‐sol system and moderately affected by temperature and by the silica
N. A. Funnell +2 more
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Physical Review B, 1977
A new theory of lattice vibrations in amorphous silicon dioxide is presented in which the randomness of the solid is treated separately from its chemistry. The theory attributes all measurable properties of phonons in silica to the nearly crystalline nearest-neighbor geometry of the lattice and to the disruptive effects of bondangle disorder.
R. B. Laughlin, J. D. Joannopoulos
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A new theory of lattice vibrations in amorphous silicon dioxide is presented in which the randomness of the solid is treated separately from its chemistry. The theory attributes all measurable properties of phonons in silica to the nearly crystalline nearest-neighbor geometry of the lattice and to the disruptive effects of bondangle disorder.
R. B. Laughlin, J. D. Joannopoulos
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First-Order Amorphous-Amorphous Transformation in Silica
Physical Review Letters, 2000Molecular simulations predict that a first-order amorphous-amorphous transformation occurs in SiO2 under pressure, analogous to the first-order amorphous-amorphous transformation known to occur in H2O. At low temperatures the first-order transformation is kinetically hindered, and an amorphous-amorphous transformation occurs instead by gradual spinodal
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Hydrophobic Transition in Porous Amorphous Silica
The Journal of Physical Chemistry B, 2011Realistic models of amorphous silica surfaces with different silanol densities are built using Monte Carlo annealing. Water-silica interfaces are characterized by their energy interaction maps, adsorption isotherms, self-diffusion coefficients, and Poiseuille flows. A hydrophilic to hydrophobic transition appears as the surface becomes purely siliceous.
Siboulet, Bertrand +3 more
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High-pressure densification of amorphous silica
Physical Review B, 1992Molecular-dynamics simulations using a recently proposed two-body potential were employed to study the structure of amorphous ${\mathrm{SiO}}_{2}$ at ambient pressure and the densification that occurs at high pressure. The structures obtained at ambient conditions are in good agreement with experiment. The oxygen coordination number about silicon atoms
, Tse, , Klug, , Le Page Y
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Properties of Silica Ceramic Made from Amorphous Silica
Key Engineering Materials, 2010The mixture of amorphous silica extracted from coal fly ash and fused silica was used to prepare density silica ceramic through slip-casting method. The XRD results showed that a large amount of cristobalite was formed at 1300°C which can weaken mechanical properties.
Cai Fen Wang +4 more
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Ion tracks in amorphous silica
Journal of Materials Research, 2015Abstract
Abdenacer Benyagoub, Marcel Toulemonde
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Free‐Standing Molecularly Thin Amorphous Silica Nanosheets
Small, 2023AbstractRecent progress in 2D materials has initiated new fields of molecularly thin amorphous materials with mysterious properties and structures. However, designed synthesis of molecularly thin amorphous silica still remains a challenge; whether free‐standing molecularly thin amorphous silica nanosheets can exist is unclear.
Eisuke Yamamoto +6 more
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Pigments on amorphous silica carriers
Powder Technology, 2003Amorphous precipitated silica was applied as a carrier for pigments. The silica surface was modified with silane coupling agents, such as 3-aminopropyltriethoxysilane,N-2-(aminoethyl)-3-aminopropyltrimethoxysilane and 3-ureidopropyltrimethoxysilane. Pigments were obtained by attaching organic dyes, C.I. Acid Red 18 and C.I. Acid Violet 1, to a modified
Andrzej Krysztafkiewicz +2 more
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