Characterization of chemically modified glass surfaces by 13C and 29Si CP/MAS NMR spectroscopy

Albert, Klaus; Pfleiderer, Bettina; Bayer, Ernst; Schnabel, R.

doi:10.1016/0021-9797(91)90031-3

Cited by 30 publications

(33 citation statements)

References 6 publications

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“…Another band assigned to protonated amines caused by the bonded SiOH group is located at 1576 cm −1 . The band attributed to the symmetric NH 3 + deformation at 1480 cm −1 gives another evidence of protonated amino groups on the surfaces (29). The band assigned to the NH group deformation is overlapped by the angular deformation band of water at 1622 cm −1 .…”

Section: Resultsmentioning

confidence: 96%

Silylating Agents Grafted onto Silica Derived from Leached Chrysotile

Fonseca

Oliveira

Airoldi

2001

Journal of Colloid and Interface Science

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Section: Resultsmentioning

confidence: 96%

Silylating Agents Grafted onto Silica Derived from Leached Chrysotile

Fonseca

Oliveira

Airoldi

2001

Journal of Colloid and Interface Science

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“…The absence of bands at 8 = 2.5 ppm proved the presence of a polymeric-type phase. The existence of unconverted ethoxy signals in the upper spectrum would imply a lower order of crosslinking in the reaction [27,28].…”

Section: Surface Characterizationmentioning

confidence: 97%

Selectivity tuning and molecular modeling of new generation packings for RP HPLC

et al. 2001

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SummaryRetention mechanism, selectivity and physicochemical properties togetherwith theoretical surface simulation experiments of laboratory-synthesized packing materials for high performance liquid chromatography (HPLC) containing cholesterol molecules immobilized on the high qualily silica gel were studied. The chromatographic behavior of the three cholesterolbased columns (SG-CHOL, SG-MIX CHOL/AP and SG-10-CHOL) was examined with special regard to retention and selectivil",/and compared to reference materials: a l',/pical octadecylsilica column (SG-C18) and an alkylamide bonded phase (SG-AP). Temperature investigations (DSC) and molecular modeling simulations didn't bring an expected confirmation of liquid crystalline properties of materials studied. The observed phase transition was attributed to conformation change within the amide bonding.

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“…Despite the large number of chromatographic procedures, many aspects related to the mechanism of separation have not yet been investigated, especially those concerning the structure of chromatographic packings. Spectroscopic methods, such as NMR, IR, fluorescence, photoacoustic spectroscopy [1][2][3][4][5] and also porosimetry, elemental and thermal analysis, gel permeation chromatography, and microcalorimetry for heats of wetting measurements have been used for the structural description of chemically bonded ligands [1,[6][7][8][9][10]. Observations of heats of wetting by organic solvents made it possible to characterize the surface energy heterogeneity and distribution of active centers.…”

Section: Introductionmentioning

confidence: 99%

Effect of coverage density and structure of chemically bonded silica stationary phases on the separation of compounds with various properties

Buszewski¹,

Krupczyńska

Rychlicki

et al. 2006

J of Separation Science

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The chemical character, geometry, and architecture of chemically formed surface layers determine interactions between stationary phase, analyte, and mobile phase, and therefore the retention mechanisms (partitioning, adsorption, ion exchange, steric exclusion) of separated analytes. These interactions also depend on the structure and chemical character of the solutes and the composition of the mobile phase. High-molecular-weight fullerenes (C60 and C70) and water-soluble selenium-containing peptides (833 and 2607 Da) were used for the evaluation of laboratory-prepared octadecyl stationary phases with high and low coverage density before and after end-capping. The aim of this work was to study differences in surface coverage density and homogeneity and conformational changes of chemically bonded moieties and the influence of these parameters on the separation of mixtures of selenopeptides and fullerenes with significantly different molecular masses. A topographical model of the chemically modified stationary surface is presented.

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Characterization of chemically modified glass surfaces by 13C and 29Si CP/MAS NMR spectroscopy

Cited by 30 publications

References 6 publications

Silylating Agents Grafted onto Silica Derived from Leached Chrysotile

Silylating Agents Grafted onto Silica Derived from Leached Chrysotile

Selectivity tuning and molecular modeling of new generation packings for RP HPLC

Effect of coverage density and structure of chemically bonded silica stationary phases on the separation of compounds with various properties

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