The Exchange of Twenty Metal Ions with the Weakly Acidic Silanol Group of Silica Gel<sup>1,2</sup>

Dugger, Donald L.; Stanton, Jimmy; Irby, Bobby N.; McConnell, Bobby L.; Cummings, William W.; Maatman, Russell W.

doi:10.1021/j100786a007

Cited by 332 publications

(107 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The nature of salt/alkoxide precursor used as a network modifier must be taken into account to fully understand crystallisation events. In the present case, the following mechanism is hypothesised: Since the analysis of the pore liquor revealed that lithium is solvated in the pore liquor during ageing, we assume that the silanol residues (Si-OH) are poor lithium chelators at the pH at which the synthesis was carried out [35]. Thus, upon drying, lithium citrate or nitrate reprecipitated within the pores and on the surface of the silica gel (Fig.…”

Section: Crystallisation Behaviour Upon Thermal Stabilisationmentioning

confidence: 77%

“…2). Due to the low decomposition temperature of citrate and the relative low bonding strength between lithium and citrate [36], a solid-state salt metathesis reaction occurred between lithium citrate and the silanol residues at a temperature where the crystallisation of lithium and silica is not thermodynamically favourable [35], as (Eq. 1):…”

Section: Crystallisation Behaviour Upon Thermal Stabilisationmentioning

confidence: 99%

See 1 more Smart Citation

Lithium-silicate sol–gel bioactive glass and the effect of lithium precursor on structure–property relationships

Maçon

Jacquemin

Page

et al. 2016

J Sol-Gel Sci Technol

View full text Add to dashboard Cite

This work reports the synthesis of lithium-silicate glass, containing 10 mol% of Li 2 O by the sol-gel process, intended for the regeneration of cartilage. Lithium citrate and lithium nitrate were selected as lithium precursors. The effects of the lithium precursor on the sol-gel process, and the resulting glass structure, morphology, dissolution behaviour, chondrocyte viability and proliferation, were investigated. When lithium citrate was used, mesoporous glass containing lithium as a network modifier was obtained, whereas the use of lithium nitrate produced relatively dense glass-ceramic with the presence of lithium metasilicate, as shown by X-ray diffraction, 29 Si and 7 Li MAS NMR and nitrogen sorption data. Nitrate has a better affinity for lithium than citrate, leading to heterogeneous crystallisation from the mesopores, where lithium salts precipitated during drying. Citrate decomposed at a lower temperature, where the crystallisation of lithium-silicate crystal is not thermodynamically favourable. Upon decomposition of the citrate, a solid-state salt metathesis reaction between citrate and silanol occurred, followed by the diffusion of lithium within the structure of the glass. Both glass and glass-ceramic released silica and lithium ions in culture media, but release rate was lower for the glass-ceramic. Both samples did not affect chondrocyte viability and proliferation.Graphical Abstract

show abstract

Section: Crystallisation Behaviour Upon Thermal Stabilisationmentioning

confidence: 77%

Section: Crystallisation Behaviour Upon Thermal Stabilisationmentioning

confidence: 99%

Lithium-silicate sol–gel bioactive glass and the effect of lithium precursor on structure–property relationships

Maçon

Jacquemin

Page

et al. 2016

J Sol-Gel Sci Technol

View full text Add to dashboard Cite

show abstract

“…In 1964. Dugger et al reported values of K,, for silica gel [42]. Exchange of K+ ions occurred with a PKex of 6.9, while a more recent value reported by Davis et al [9] for pyrogenic silica was 6.7.…”

Section: Discussionmentioning

confidence: 90%

The influence of counter-ion adsorption on the ψ0/pH characteristics of insulator surfaces

1983

View full text Add to dashboard Cite

The site-binding theory of Yates, Levine, and Healy is extended to include the possibility that counter-ion binding of anions and cations occurs at different distances from the insulator surface. A method for straightforward computation of the $,,/ea/pH characteristics is given. This theory is applied to the study of electrolyte/insulator/silicon structures, which makes it possible to measure the $e/pH characteristics. Measurements are presented for structures where the insulator is y-AlaO, deposited by chemical vapour deposition at 900°C. The influence of counter-ion binding on the +e/pH curves is a second-order effect compared to the site-dissociation acid/base reactions, but it is clearly visible. Consideration of the influence of the ionic strength of the electrolyte leads to an estimated anion adsorption equilibrium constant in the range of 0.05 to 0.4 mol-' dm3 in chloride solutions, although no significant influence of the type of ions present could be observed. Application of the theory to existing measurements of the +,,/pH and oa/pH curves of SiO, surfaces indicates that for this material the cation adsorption equilibrium constant is in the order of 0.1 mol-' dm3.

show abstract

“…A number of studies have been carried out on the ionexchange capacities of various forms of silica gel for divalent cations, including transition and heavy metal ions [25][26][27][28][29][30][31][32]. In many cases, these investigations have studied relatively large particle size silica gels, and have not investigated high-performance phases for ion chromatographic separations.…”

Section: Transition Metals-organic Solvent and Buffer Effectsmentioning

confidence: 99%

Solvent enhanced ion chromatography of alkaline earth and transition metal ions on porous monolithic silica

Sugrue

Nesterenko

Paull

2005

Analytica Chimica Acta

View full text Add to dashboard Cite

The high-performance separation of alkaline earth and transition metal ions on a bare porous silica 10.0 cm × 0.46 cm monolith (Merck Chromolith Si) was achieved using solvent enhanced ion chromatography. Using acetonitrile or methanol based ammonium and sodium acetate buffered mobile phases, the effect upon cation retention of mobile phase ionic strength, organic content and pH were evaluated. Increasing mobile phase acetonitrile concentration from 60 to 80% acetonitrile resulted in 10-15-fold increases in cation retention due to reduced hydration of the metal ions and hence enhanced ion-exchange interactions with surface silanol groups. The optimised conditions for the separation of Cu(II), Cd(II), Ni(II), Co(II) and Mn(II) were found to be 80% MeCN with 10.3 mM ammonium acetate (pH 4.6). Detection of transition metal ions was obtained using post-column reaction with 4-(2-pyridylazo) resorcinol and absorbance at 510 nm. Under elevated flow conditions (up to 5 mL/min), total runs times could be reduced to under 4 min. Optimum peak efficiencies were seen at flow rates of between 1.5 and 2 mL/min and were equivalent to an average efficiency of 25,000 N/m.

show abstract

The Exchange of Twenty Metal Ions with the Weakly Acidic Silanol Group of Silica Gel^1,2

Cited by 332 publications

References 0 publications

Lithium-silicate sol–gel bioactive glass and the effect of lithium precursor on structure–property relationships

Lithium-silicate sol–gel bioactive glass and the effect of lithium precursor on structure–property relationships

The influence of counter-ion adsorption on the ψ0/pH characteristics of insulator surfaces

Solvent enhanced ion chromatography of alkaline earth and transition metal ions on porous monolithic silica

Contact Info

Product

Resources

About

The Exchange of Twenty Metal Ions with the Weakly Acidic Silanol Group of Silica Gel1,2

Cited by 332 publications

References 0 publications

Lithium-silicate sol–gel bioactive glass and the effect of lithium precursor on structure–property relationships

Lithium-silicate sol–gel bioactive glass and the effect of lithium precursor on structure–property relationships

The influence of counter-ion adsorption on the ψ0/pH characteristics of insulator surfaces

Solvent enhanced ion chromatography of alkaline earth and transition metal ions on porous monolithic silica

Contact Info

Product

Resources

About

The Exchange of Twenty Metal Ions with the Weakly Acidic Silanol Group of Silica Gel^1,2