Silica gel dissolution in aqueous alkali metal hydroxides studied by 29SiNMR

Wijnen, P.W.J.G.; Beelen, Theo P. M.; Haan, J.W. de; Rummens, C.P.J.; Ven, L.J.M. van de; Santen, Rutger A. van

doi:10.1016/0022-3093(89)90446-8

Cited by 109 publications

(58 citation statements)

References 25 publications

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“…This indicates that the formation of insoluble three-dimensional framework in a sodium silicate system occurs faster than in potassium one. The observed difference in the dissolution behavior appears to relate both to the phase formation manner and that fact that cations of potassium being a water structure breakers more effectively promotes dissolution of silica gel than cations of sodium [30]. In addition, as it has been previously mentioned, potassium silicate binder contains an excess amount of hydrosilicate glass which is more soluble than silica gel.…”

Section: Hydrolytic Stabilitymentioning

confidence: 71%

Alkali silicate binders: effect of SiO2/Na2O ratio and alkali metal ion type on the structure and mechanical properties

Skorina

Тихомирова

2012

J Mater Sci

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The influence of SiO 2 :Na 2 O molar ratio and the nature of an alkali metal (Na vs. K) in commercial aqueous alkali silicate on the microstructure, textural properties, phase composition, and hydrolytic stability of an alkali silicate binder have been investigated using scanning electron microscopy, nitrogen adsorption/desorption technique, X-ray diffractometry, thermal analysis, and dissolution tests. It has been found that microstructure and textural properties of the alkali silicate binder depend both on silica to alkali molar ratio and type of alkali metal (Na vs. K). Sodium silicate binder obtained from commercial silicate solution with lower SiO 2 :Na 2 O molar ratio (2.2) exhibits a globular microstructure of silica xerogel with high content of micropores, whereas the binder formulated with SiO 2 :Na 2 O molar ratio 3.2 is characterized by more open cluster structure with lower content of micropores. It is observed that surface specific area estimated by Brunauer, Emmett, and Teller method and mesopore volume obtained by the Barrett-Joyner-Halenda method for sodium silicate binder are substantially higher than those for potassium silicate binder. The ultimate hydrolytic stability of the sodium silicate binder increases slightly with increase in the silica to alkali molar ratio within the studied range. Decreasing in SiO 2 :Na 2 O molar ratio and replacement of sodium silicate solution by potassium silicate solution in the corresponding filled composition lead to the improvement of mechanical properties and decrease in open porosity.

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Section: Hydrolytic Stabilitymentioning

confidence: 71%

Alkali silicate binders: effect of SiO2/Na2O ratio and alkali metal ion type on the structure and mechanical properties

Skorina

Тихомирова

2012

J Mater Sci

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“…The synthesis of PMS was done initially by activation of silica gel with NaOH [28], followed by grafting of 1,4-dibromobutane onto silica gel surface [18] and finally by grafting of phosphonate onto 1,4-dibromobutane previously grafted onto silica. As an adsorbent, the resulting material has been analyzed its physical and chemical character, such as active sites and pores properties [29].…”

Section: Physical and Chemical Characteristic Of Adsorbentmentioning

confidence: 99%

Phosphonate Modified Silica for Adsorption of Co(II), Ni(II), Cu(II), and Zn(II)

Widjonarko¹,

Jumina²,

Kartini³

et al. 2014

Indones. J. Chem.

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A new phosphonate modified silica (PMS) has been investigated for adsorption of Co(II), Ni(II), Cu(II), andZn (II) II)>Co(II)>Ni(II)>Zn(II). Based on the adsorption characteristic, the adsorbent is promising to be applied as a material for solid phase extraction of transition metal ions. Keywords: modified silica; phosphonate; adsorption ABSTRAK Suatu silika termodifikasi fosfonat (STF) baru telah dikaji sebagai adsorben larutan Co(II), Ni(II), Cu(II), dan Zn(II). STF disintesis dengan mengimobilisasi aminoetil dihidrogen fosfat (AEPH

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“…8 The simplest interpretation of a secondorder reaction is that two water molecules take part in the rate-determining step, which seems unlikely. Alternatively, the strength of silica decreases with pH, [31][32][33][34] indicating that the glass is reacting with OH Ϫ . Assuming that some dissociation of an adsorbed water layer occurs, we may consider the following equilibrium:…”

Section: (1) Reaction Ordermentioning

confidence: 99%

Humidity Dependence of the Fatigue of High‐Strength Fused Silica Optical Fibers

Armstrong

Matthewson

Kurkjian³

2000

Journal of the American Ceramic Society

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Strength and dynamic fatigue behavior of silica fibers has been measured as a function of ambient humidity. Bare and polymer-coated fibers were compared to determine the influence of the coating. The results verify earlier work that suggests the degradation reaction is approximately second order with respect to humidity. However, we verify this result using rigorous data analysis techniques and, unlike the earlier work, the result is shown to be independent of the form of the kinetic model for crack growth. Trends in the calculated fatigue parameters illustrate that a simple exponential crack growth law best describes the humidity data. No significant differences were found between coated and bare fibers, provided the coated fibers were properly equilibrated. A data analysis methodology is given for obtaining valid reaction orders independently of the crack growth law form.

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Silica gel dissolution in aqueous alkali metal hydroxides studied by 29SiNMR

Cited by 109 publications

References 25 publications

Alkali silicate binders: effect of SiO2/Na2O ratio and alkali metal ion type on the structure and mechanical properties

Alkali silicate binders: effect of SiO2/Na2O ratio and alkali metal ion type on the structure and mechanical properties

Phosphonate Modified Silica for Adsorption of Co(II), Ni(II), Cu(II), and Zn(II)

Humidity Dependence of the Fatigue of High‐Strength Fused Silica Optical Fibers

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