Study of Hydrated Structures on the Surface of Mesoporous Silicas and Carbosils by1H NMR Spectroscopy of Adsorbed Water†

Langmuir ◽  
1997 ◽  
Vol 13 (5) ◽  
pp. 1237-1244 ◽  
Author(s):  
V. V. Turov ◽  
R. Leboda ◽  
V. I. Bogillo ◽  
J. Skubiszewska-Ziȩba
Keyword(s):  
Nmr Spectroscopy ◽  
Adsorbed Water ◽  
Mesoporous Silicas

Deuterium NMR Spectroscopy of Solvents Adsorbed onto the Surface of Mesoporous Silica

1996 ◽  
Vol 425 ◽  
Author(s):  
George S. Attard ◽  
Mark Edgar ◽  
James W. Emsley ◽  
Christine G. Göltner
Keyword(s):  
Nmr Spectroscopy ◽  
Orientational Order ◽  
Domain Size ◽  
Mesoporous Silicas ◽  
Deuterium Nmr ◽  
Nmr Spectrum ◽  
Domain Boundaries ◽  
Uniform Diameter ◽  
Degree Of Order ◽  
Mcm 41

AbstractA series of simple deuterium NMR experiments are used to investigate the surfaces of differently structured silicas by studying the sorption of deuteriated solvents. Two mesoporous silicas (MCM-41 and H1-silica), which display hexagonally arranged channels of uniform diameter are studied, as well as amorphous column silica. The deuterium NMR lineshape strongly depends on the anisotropic environment of the adsorbed deuteriated species (D2O, benzene-d6, pyridine-d5). This allows differentiation between probe molecules adsorbed to the internal surface (anisotropic) and to the external surface (isotropic, non-ordered surface of particles). Solvents adsorbed within the channels of the silica nanostructure retain a degree of orientational order while moving on the surface, thus producing a Pake pattern. In contrast, solvents adsorbed on the outside of the ordered channels and on domain boundaries retain no orientational order while moving on the surface, therefore giving rise to a singlet in the deuterium NMR spectrum. This phenomenon allows to judge and compare the qualities of hexagonal ceramic nanostructures. The results show that H1-silica exhibits a significantly higher degree of order, due to a larger domain size, than MCM-41.

An NMR study on the mechanisms of freezing and melting of water confined in spherically mesoporous silicas SBA-16

2016 ◽  
Vol 18 (27) ◽  
pp. 18555-18562 ◽  
Author(s):  
Tatsuya Miyatou ◽  
Ryutaro Ohashi ◽  
Tomonori Ida ◽  
Shigeharu Kittaka ◽  
Motohiro Mizuno
Keyword(s):  
Relaxation Time ◽  
Nmr Spectroscopy ◽  
Dynamic Properties ◽  
Lattice Relaxation ◽  
Lattice Relaxation Time ◽  
Mesoporous Silicas ◽  
Spin Lattice Relaxation ◽  
Spin Lattice ◽  
H Nmr ◽  
Nmr Study

Thermodynamic and dynamic properties of water confined in mesoporous silica glass SBA-16 were investigated by DSC and 1,2H NMR spectroscopy and 2H NMR spin–lattice relaxation time as a function of pore size.

Photoinduced Changes of Surface and Adsorbed Water in TiO2Photocatalytic Systems as Studied by Solid State1H-NMR Spectroscopy

2002 ◽  
Vol 31 (3) ◽  
pp. 420-421 ◽  
Author(s):  
Atsuko Y. Nosaka ◽  
Toshimichi Fujiwara ◽  
Hiromasa Yagi ◽  
Hideo Akutsu ◽  
Yoshio Nosaka
Keyword(s):  
Nmr Spectroscopy ◽  
Adsorbed Water ◽  
Photoinduced Changes

Photoinduced Changes of Adsorbed Water on a TiO2Photocatalytic Film As Studied by1H NMR Spectroscopy

2003 ◽  
Vol 107 (44) ◽  
pp. 12042-12044 ◽  
Author(s):  
Atsuko Y. Nosaka ◽  
Eiichi Kojima ◽  
Toshimichi Fujiwara ◽  
Hiromasa Yagi ◽  
Hideo Akutsu ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Adsorbed Water ◽  
Photoinduced Changes

Hydrated form of some clay minerals observed using a film sealed environmental cell

1978 ◽  
Vol 36 (1) ◽  
pp. 72-73
Author(s):  
N. Kohyama ◽  
K. Fukushima ◽  
A. Fukami
Keyword(s):  
Clay Minerals ◽  
Morphological Changes ◽  
Carbon Film ◽  
Electron Microscopic Observation ◽  
Adsorbed Water ◽  
Electron Microscopic ◽  
Hydrated Form ◽  
Thin Carbon ◽  
Environmental Cell ◽  
Thin Carbon Film

Since the interlayer or adsorbed water of some clay minerals are quite easily dehydrated in dried air, in vacuum, or at moderate temperatures even in the atmosphere, the hydrated forms have not been observed by a conventional electron microscope(TEM). Recently, specific specimen chambers, “environmental cells(E.C.),” have been developed and confirmed to be effective for electron microscopic observation of wet specimen without dehydration. we observed hydrated forms of some clay minerals and their morphological changes by dehydration using a TEM equipped with an E.C..The E.C., equipped with a single hole copper-microgrid sealed by thin carbon-film, attaches to a TEM(JEM 7A) with an accelerating voltage 100KV and both gas pressure (from 760 Torr to vacuum) and relative humidity can be controlled. The samples collected from various localities in Japan were; tubular halloysite (l0Å) from Gumma Prefecture, sperical halloysite (l0Å) from Tochigi Pref., and intermediate halloysite containing both tubular and spherical types from Fukushima Pref..

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