Hysteresis Critical Point of Nitrogen in Porous Glass: Occurrence of Sample Spanning Transition in Capillary Condensation

Langmuir ◽  
2009 ◽  
Vol 25 (11) ◽  
pp. 6221-6226 ◽  
Author(s):  
Kunimitsu Morishige
Keyword(s):  
Critical Point ◽  
Porous Glass ◽  
Capillary Condensation

A Chord Distribution Description of Porous Glass

1990 ◽  
Vol 195 ◽  
Author(s):  
M. Y. Lin ◽  
S. K. Sinha
Keyword(s):  
Porous Medium ◽  
Neutron Scattering ◽  
Porous Glass ◽  
Small Angle ◽  
Small Angle Neutron Scattering ◽  
Capillary Condensation ◽  
Scattering Data ◽  
Distribution Model ◽  
Microporous Structure ◽  
Good Agreement

ABSTRACTSmall angle neutron scattering data of Vycor is analyzed using a chord distribution model describing the microporous structure. In addition, the same model is applied in interpreting the data taken when capillary condensation takes place in the porous medium. In both cases, the results are in good agreement with other measurements, and shows a promising potential in describing such a bicontinuous system.

Infrared spectroscopic study of the hydration of porous glass

1989 ◽  
Vol 54 (4) ◽  
pp. 878-891 ◽  
Author(s):  
Ondřej Ivanek ◽  
Pavel Schmidt ◽  
Bohdan Schneider
Keyword(s):  
Hydrogen Bonds ◽  
Spectroscopic Study ◽  
Infrared Spectra ◽  
Porous Glass ◽  
Glass Surface ◽  
Capillary Condensation ◽  
Water Molecules ◽  
Infrared Spectroscopic Study ◽  
Native State ◽  
Oh Groups

Infrared spectra of mesoporous and macroporous siliceous glasses were measured in the native state and after silylation, at various contents of H2O and D2O. By analysis of these spectra it was found that water is bound to the glass surface by strong hydrogen bonds between the water molecules and isolated Si-OH groups; capillary condensation was observed only in native mesoporous glasses.

scholarly journals Interaction of Ethanol Vapour with Silane-Modified Surface of Corning Porous Glass CPG-10

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
Misael Silas Nadiye-Tabbiruka
Keyword(s):  
Adsorption Isotherm ◽  
Porous Glass ◽  
Capillary Condensation ◽  
Type Ii ◽  
Ethanol Vapour ◽  
Surface Areas ◽  
Type Iv ◽  
Similar Dependence ◽  
Modified Surface ◽  
Ethanol Adsorption

The interaction of ethanol vapour at 293 K with modified Corning controlled porous glass (CPG-10) samples of various pre-silylation is reported. Ethanol adsorption on CPG-10 was greatly reduced by silylation to extents largely depending on the silylation extent, type of silane used, and on the concentration and accessibility of residual silanols. The obtained adsorption isotherms, BET surface areas, as well as the observed changes at the various stages during the sorption particularly in the capillary condensation region also showed similar dependence. In the capillary condensation region, in the case of the dimethyl dichlorosilane-modified sample, hysteresis type was changed from H3 to H1. On the triethyl chlorosilane-modified sample an unexpected suppression of hysteresis effects occurred with a consequent transformation of type IV to type II adsorption isotherm.

Simple Universal Kelvin Equation Valid in the Critical Point Vicinity, External-Internal State Correction, and their Application to Nitrogen Capillary Condensation in Mesoporous Silica SBA-15

2018 ◽  
Vol 284 ◽  
pp. 801-806 ◽  
Author(s):  
Anton A. Valeev ◽  
Elena V. Morozova
Keyword(s):  
Experimental Data ◽  
Porous Medium ◽  
Phase Equilibrium ◽  
Mesoporous Silica ◽  
Critical Point ◽  
Capillary Condensation ◽  
Internal State ◽  
Curvature Radius ◽  
Universal Form ◽  
Kelvin Equation

A new simple universal form of the Kelvin equation, which can be used near the gas-liquid critical point and the correction of the pressure for vapor outside the porous medium are used for the N2 meniscus effective curvature radius calculation at the phase equilibrium in mesoporous silica SBA-15, on the basis of the capillary condensation experimental data.

Determination of the pore-size distributions and pore-space interconnectivity of Vycor porous glass from adsorption-desorption hysteresis capillary condensation isotherms

1988 ◽  
Vol 415 (1849) ◽  
pp. 453-486 ◽  
Keyword(s):  
Size Distribution ◽  
Porous Glass ◽  
Capillary Condensation ◽  
Pore Space ◽  
Surface Adsorption ◽  
Window Size ◽  
Cavity Size ◽  
Pore Sizes ◽  
The Family ◽  
Scanning Curves

A model of a chaotic pore space in which cavities are randomly connected together by constrictions or windows is given. The behaviour of the system is described in terms of the cavity-size distribution, the window-size distribution, and the number of windows per cavity. A Bethe tree is used as the network of pore connections. The analysis of capillary condensation adsorption and desorption scanning curves is described, and the conclusion is drawn that desorption scanning curves are the more valuable in terms of the information that can be derived from them. This model is applied to the large number of scanning isotherms obtained by A. J. Brown (Ph. D. thesis, University of Bristol (1963)) for xenon on Vycor porous glass at 151 K. A method of correlating the results is given in which there is no need to separate the amount of capillary condensation from the amount of surface adsorption. The family of adsorption isotherms confirms the theory but some systematic differences remain. The family of desorption isotherms is used in a simple method that gives an estimate of the cavity-size distribution in terms of the Kelvin radius. The same isotherms are used in a more complicated method to give an estimate of the number of windows per cavity, together with a more precise cavity-size distribution and a window-size distribution. These results are then used to calculate the thickness of the surface adsorption. This enables the geometric pore sizes to be obtained from the Kelvin pore sizes. The cavity-size distribution thus obtained is in agreement with published values.

Peculiarities of the capillary condensation of carbon dioxide in the vicinity of the critical point

2014 ◽  
Vol 8 (7) ◽  
pp. 984-990
Author(s):  
D. A. Zimnyakov ◽  
S. P. Chekmasov ◽  
A. P. Sviridov ◽  
O. V. Ushakova ◽  
V. N. Bagratashvili
Keyword(s):  
Carbon Dioxide ◽  
Critical Point ◽  
Capillary Condensation

Simple Universal Kelvin Equation Valid in Critical Point Vicinity and its Application to Carbon Dioxide Capillary Condensation in Mesoporous Silica

2017 ◽  
Vol 265 ◽  
pp. 392-397 ◽  
Author(s):  
A.A. Valeev ◽  
E.V. Morozova
Keyword(s):  
Mesoporous Silica ◽  
Critical Point ◽  
Chemical Potential ◽  
Capillary Condensation ◽  
Curvature Radius ◽  
Liquid Phase Transition ◽  
Kelvin Equation ◽  
Wide Range ◽  
Potential Pressure ◽  
Mcm 41

A new simple universal form of the Kelvin equation that can be used even near the gas-liquid phase transition critical point is shown. The correction of the chemical potential, pressure, and density outside the porous medium is presented and taken into account for the CO2 meniscus curvature radius calculation at capillary condensation in mesoporous silica MCM-41, known [1] for its wide range of applications.

scholarly journals A Monte Carlo test of the Fisher–Nakanishi–Scaling theory for the capillary condensation critical point

2001 ◽  
Vol 114 (13) ◽  
pp. 5853-5862 ◽  
Author(s):  
Oliver Dillmann ◽  
Wolfhard Janke ◽  
Marcus Müller ◽  
Kurt Binder
Keyword(s):  
Monte Carlo ◽  
Critical Point ◽  
Capillary Condensation ◽  
Scaling Theory ◽  
Monte Carlo Test
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