Characterization by vanadium-51 solid-state NMR, laser Raman, and x-ray photoelectron spectroscopy of vanadium species deposited on .gamma.-Al2O3

1988 ◽  
Vol 92 (5) ◽  
pp. 1230-1235 ◽  
Author(s):  
L. R. Le Coustumer ◽  
B. Taouk ◽  
M. Le Meur ◽  
E. Payen ◽  
M. Guelton ◽  
...  
Keyword(s):  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Solid State Nmr ◽  
X Ray ◽  
Laser Raman ◽  
Vanadium Species

29Si NMR and XPS Investigation of the Structure of Silicon Oxycarbide Glasses Derived from Polysiloxane Precursors

1994 ◽  
Vol 346 ◽  
Author(s):  
R.J.P. Corriu ◽  
D. Leclercq ◽  
P.H. Mutin ◽  
A. Vioux
Keyword(s):  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Solid State Nmr ◽  
Random Distribution ◽  
Silicon Oxycarbide ◽  
29Si Nmr ◽  
Xps Spectra ◽  
Excess Carbon ◽  
X Ray ◽  
Silicon Oxycarbide Glasses

ABSTRACTTwo silicon oxycarbide glasses with different compositions (O/Si ratio 1.2 and 1.8) were prepared by pyrolysis at moderate temperature (900 °C) of polysiloxane precursors. Their structure was investigated using quantitative 29Si solid-state NMR and X-ray photoelectron spectroscopy (XPS). The environment of the silicon atoms in the oxycarbide phase corresponded to a purely random distribution of Si-O and Si-C bonds depending on the O/Si ratio of the glass only and not on the structure of the precursors. At the light of the NMR results, the Si2p XPS spectra of the glasses may be interpreted using the contribution of the five possible SiOxC4-x tetrahedra. The Cls spectra of these glasses indicated the presence of oxycarbide carbon in CSi4 tetrahedra, similar to carbide carbon, and graphitic-like excess carbon.

Structural investigation of SnO–B2O3 glasses by solid-state NMR and X-ray photoelectron spectroscopy

2002 ◽  
Vol 306 (3) ◽  
pp. 227-237 ◽  
Author(s):  
Akitoshi Hayashi ◽  
Miyuki Nakai ◽  
Masahiro Tatsumisago ◽  
Tsutomu Minami ◽  
Yusuke Himei ◽  
...  
Keyword(s):  
Solid State ◽  
Photoelectron Spectroscopy ◽  
Solid State Nmr ◽  
Structural Investigation ◽  
X Ray

ESCA and solid-state NMR studies of allophane

Clay Minerals ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 201-209 ◽  
Author(s):  
N. He ◽  
T. L. Barr ◽  
J. Klinowski
Keyword(s):  
Solid State ◽  
Surface Chemistry ◽  
Photoelectron Spectroscopy ◽  
Solid State Nmr ◽  
Bulk Material ◽  
Binding Energies ◽  
Nmr Studies ◽  
Near Surface ◽  
X Ray ◽  
The Core

AbstractThe surface/near-surface chemistry of allophane has been studied by X-ray photoelectron spectroscopy (ESCA) and the bulk material by 27A1 and 29Si solid-state NMR and other techniques. The surface/near-surface Si/Al ratio of allophane is c.1.0, similar to that for kaolinite, zeolite Na-A and sodalite. The core level binding energies for kaolinite and allophane are almost identical, but quite different from those for zeolite Na-A and sodalite, both framework aluminosilicates. The nature and size of these differences is consistent with the differences between the chemistry of sheet and framework silicates. The small variations in the Si(2p) spectra for kaolinite and allophane are discussed in terms of bonding of the tetrahedral units in the two materials.

scholarly journals A Multi-Method Approach for Quantification of Surface Coatings on Commercial Zinc Oxide Nanomaterials

Nanomaterials ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 678 ◽  
Author(s):  
Filip Kunc ◽  
Oltion Kodra ◽  
Andreas Brinkmann ◽  
Gregory P. Lopinski ◽  
Linda J. Johnston
Keyword(s):  
Solid State ◽  
Functional Groups ◽  
Photoelectron Spectroscopy ◽  
Solid State Nmr ◽  
Functional Group ◽  
Surface Groups ◽  
X Ray ◽  
Ft Ir ◽  
Multi Method Approach ◽  
Method Approach

Surface functionalization is a key factor for determining the performance of nanomaterials in a range of applications and their fate when released to the environment. Nevertheless, it is still relatively rare that surface groups or coatings are quantified using methods that have been carefully optimized and validated with a multi-method approach. We have quantified the surface groups on a set of commercial ZnO nanoparticles modified with three different reagents ((3-aminopropyl)-triethoxysilane, caprylsilane and stearic acid). This study used thermogravimetric analysis (TGA) with Fourier transform infrared spectroscopy (FT-IR) of evolved gases and quantitative solution 1H nuclear magnetic resonance (NMR) for quantification purposes with 13C-solid state NMR and X-ray photoelectron spectroscopy to confirm assignments. Unmodified materials from the same suppliers were examined to assess possible impurities and corrections. The results demonstrate that there are significant mass losses from the unmodified samples which are attributed to surface carbonates or residual materials from the synthetic procedure used. The surface modified materials show a characteristic loss of functional group between 300–600 °C as confirmed by analysis of FT-IR spectra and comparison to NMR data obtained after quantitative release/extraction of the functional group from the surface. The agreement between NMR and TGA estimates for surface loading is reasonably good for cases where the functional group accounts for a relatively large fraction of the sample mass (e.g., large groups or high loading). In other cases TGA does not have sufficient sensitivity for quantitative analysis, particularly when contaminants contribute to the TGA mass loss. X-ray photoelectron spectroscopy and solid state NMR for selected samples provide support for the assignment of both the functional groups and some impurities. The level of surface group loading varies significantly with supplier and even for different batches or sizes of nanoparticles from the same supplier. These results highlight the importance of developing reliable methods to detect and quantify surface functional groups and the importance of a multi-method approach.

scholarly journals Polymorphs of Rb3ScF6: X-ray and Neutron Diffraction, Solid-State NMR, and Density Functional Theory Calculations Study

2021 ◽  
Vol 60 (8) ◽  
pp. 6016-6026
Author(s):  
Aydar Rakhmatullin ◽  
Maxim S. Molokeev ◽  
Graham King ◽  
Ilya B. Polovov ◽  
Konstantin V. Maksimtsev ◽  
...  
Keyword(s):  
Density Functional Theory ◽  
Solid State ◽  
Neutron Diffraction ◽  
Solid State Nmr ◽  
Density Functional ◽  
Density Functional Theory Calculations ◽  
Functional Theory ◽  
X Ray

scholarly journals A New Methodological Approach to Correlate Protective and Microscopic Properties by Soft X-ray Microscopy and Solid State NMR Spectroscopy: The Case of Cusa’s Stone

2021 ◽  
Vol 11 (13) ◽  
pp. 5767
Author(s):  
Veronica Ciaramitaro ◽  
Alberto Spinella ◽  
Francesco Armetta ◽  
Roberto Scaffaro ◽  
Emmanuel Fortunato Gulino ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Solid State Nmr ◽  
Methodological Approach ◽  
Polymer Chains ◽  
General Question ◽  
Protective Agent ◽  
Vapour Permeability ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Hydrophobic treatment is one of the most important interventions usually carried out for the conservation of stone artefacts and monuments. The study here reported aims to answer a general question about how two polymers confer different protective performance. Two fluorinated-based polymer formulates applied on samples of Cusa’s stone confer a different level of water repellence and water vapour permeability. The observed protection action is here explained on the basis of chemico-physical interactions. The distribution of the polymer in the pore network was investigated using scanning electron microscopy and X-ray microscopy. The interactions between the stone substrate and the protective agents were investigated by means of solid state NMR spectroscopy. The ss-NMR findings reveal no significant changes in the chemical neighbourhood of the observed nuclei of each protective agent when applied onto the stone surface and provide information on the changes in the organization and dynamics of the studied systems, as well as on the mobility of polymer chains. This allowed us to explain the different macroscopic behaviours provided by each protective agent to the stone substrate.

Cross-β Spine Architecture of Fibrils Formed by the Amyloidogenic Segment NFGSVQFV of Medin from Solid-State NMR and X-ray Fiber Diffraction Measurements†

Biochemistry ◽  
2009 ◽  
Vol 48 (14) ◽  
pp. 3089-3099 ◽  
Author(s):  
Jillian Madine ◽  
Alastair Copland ◽  
Louise C. Serpell ◽  
David A. Middleton
Keyword(s):  
Solid State ◽  
Solid State Nmr ◽  
X Ray ◽  
Fiber Diffraction

scholarly journals Synthesis, characterization and modeling of self-assembled porphyrin nanorods

2019 ◽  
Vol 23 (11n12) ◽  
pp. 1346-1354 ◽  
Author(s):  
Danielle Laurencin ◽  
Pascal G. Yot ◽  
Christel Gervais ◽  
Yannick Guari ◽  
Sébastien Clément ◽  
...  
Keyword(s):  
Solid State ◽  
Nmr Spectroscopy ◽  
Dft Calculations ◽  
Powder Diffraction ◽  
Solid State Nmr ◽  
Molecular Level ◽  
Ion Association ◽  
Free Base ◽  
X Ray ◽  
Solid State Nmr Spectroscopy

Porphyrin nanorods were prepared by ion-association between free-base meso 5,10,15,20-tetrakis-(4-[Formula: see text]-methylpyridinium)porphyrin cations and tetraphenylborate anions. The nanorods have variable lengths (up to a few micrometers long) and diameters ([Formula: see text]50–500 nm). Their structure at the molecular level was elucidated by combining multinuclear solid state NMR spectroscopy, synchrotron X-ray powder diffraction and DFT calculations.

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