A silicon-29 NMR study of the silanol population at the surface of derivatized silica

Tuel, A.; Hommel, H.; Legrand, A.P.; Kováts, Ervin sz.

doi:10.1021/la00094a009

Cited by 60 publications

(68 citation statements)

References 3 publications

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“…Scheme of the vapor-phase APTES reaction on plasma-activated silicon surface. [44][45][46]. The surface density of amines was found in the present work to be very similar, though slightly lower, for substrates prepared via vapor phase.…”

Section: Resultssupporting

confidence: 71%

Vapor-phase self-assembled monolayers of aminosilane on plasma-activated silicon substrates

Fiorilli

Rivolo

Descrovi

et al. 2008

Journal of Colloid and Interface Science

131

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Section: Resultssupporting

confidence: 71%

Vapor-phase self-assembled monolayers of aminosilane on plasma-activated silicon substrates

Fiorilli

Rivolo

Descrovi

et al. 2008

Journal of Colloid and Interface Science

131

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“…Silica surfaces contain a large number of silanol groups with zero (called Q4), one (Q3), or two OH groups (Q2) (Tuel et al 1990;Legrand et al 2005) (Figure 2a). If OH groups are responsible for the silica-lignin linkage, steric forces could increase the stability of silica in the polymeric matrix.…”

Section: Introductionmentioning

confidence: 99%

Solid-state ²⁹Si NMR and FTIR analyses of lignin-silica coprecipitates

Cabrera

Larsen

et al. 2016

Holzforschung

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When agricultural residues are processed to ethanol, lignin and silica are some of the main byproducts. Separation of these two products is difficult and the chemical interactions between lignin and silica are not well described. In the present study, the effect of lignin-silica complexing has been investigated by characterizing lignin and silica coprecipitates by FTIR and solid state NMR. Silica particles were coprecipitated with three different lignins, three lignin model compounds, and two silanes representing silica-inlignin model compounds. Comparison of 29 Si SP/MAS NMR spectra revealed differences in the distribution of silanol hydroxyl groups among different coprecipitates. These differences are dependent on the lignin type. The results are interpreted that the underlying mechanism of the interactions is the formation of hydrogen bonds between lignin aliphatic hydroxyl or carboxyl groups and the silanols, but not a condensation of the silica-inlignin among the silica particles and not the formation of C-O-Si bonds.

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“…Silica and diatomite have been studied using spectroscopic techniques such as IR [3,15,22,37,38], Raman [3,39,40], and NMR (including 1 H and 29 Si analyses using solid-state NMR spectroscopy techniques [17,20,38,[40][41][42][43][44]). Other works focused on surface modification [20,[45][46][47][48].…”

Section: Introductionmentioning

confidence: 99%

Effect of pretreatment temperature on the surface modification of diatomite with trimethylchlorosilane

et al. 2016

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Diatomite samples from Costa Rica were purified using acidic treatments with hydrochloric acid, thermally treated (400-1000°C) and then silylated with trimethylchlorosilane in toluene under inert atmosphere. The purification process allows to decrease the concentration of metals presented in the crude diatomite, as is confirmed by X-ray Fluorescence (XRF) Analysis. The silylated materials were analyzed by using Hyperpolarized 129 Xe Nuclear Magnetic Resonance Spectroscopy (HP 129 Xe NMR), Fourier Transform Infrared Spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), Thermogravimetric Analysis (TGA), rehydration tests, and contact angle measurements. XRD measurements indicate that diatomite is mainly amorphous, but presents several crystalline phases (kaolinite, cristobalite, and quartz). Pretreatments at high temperatures cause changes in those crystalline phases, resulting in more amorphous materials. However, there is no difference in the overall structure of purified and thermally treated diatomite samples with respect to the silylation products. In addition, SEM measurements show no effect over the pore structure of the materials. On the other hand, TGA measurements and rehydration tests show lower losses of water for silylated materials prepared using higher pretreatment temperatures. Moreover, HP 129 Xe NMR, FTIR, and contact angle measurements evidence a modification due to covalent attachment of Si(CH 3 ) 3 -groups to the surface, which increases for higher pretreatment temperatures. The results provide valuable information about external factors that influence the surface modification of diatomite. This can be useful to control modifications that can be achieved in a similar way.

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A silicon-29 NMR study of the silanol population at the surface of derivatized silica

Cited by 60 publications

References 3 publications

Vapor-phase self-assembled monolayers of aminosilane on plasma-activated silicon substrates

Vapor-phase self-assembled monolayers of aminosilane on plasma-activated silicon substrates

Solid-state ²⁹Si NMR and FTIR analyses of lignin-silica coprecipitates

Effect of pretreatment temperature on the surface modification of diatomite with trimethylchlorosilane

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A silicon-29 NMR study of the silanol population at the surface of derivatized silica

Cited by 60 publications

References 3 publications

Vapor-phase self-assembled monolayers of aminosilane on plasma-activated silicon substrates

Vapor-phase self-assembled monolayers of aminosilane on plasma-activated silicon substrates

Solid-state 29Si NMR and FTIR analyses of lignin-silica coprecipitates

Effect of pretreatment temperature on the surface modification of diatomite with trimethylchlorosilane

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Solid-state ²⁹Si NMR and FTIR analyses of lignin-silica coprecipitates