Thermoporometry.

Jallut, Christian; Lenoir, J.; Bardot, C.; Eyraud, Christelle

doi:10.1016/0376-7388(92)85028-h

Cited by 27 publications

(12 citation statements)

References 20 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The melting points of ice in porous silica gels are affected by their pore sizes and estimated by , where is the bulk melting temperature (273.15 K), σ IW is the interfacial tension (0.027 J/m 2 ) between ice and liquid water phases, ρ w is the specific density of water (1000 kg/m 3 ), Δ H fw is the specific enthalpy of fusion of water (333 kJ/kg), and r is the pore radius. The lower quadruple point ( Q 1 ) where four phases (H, I, L W , and V) coexist appears normally adjacent to the corresponding melting point of ice.…”

Section: Resultsmentioning

confidence: 99%

Methane and Carbon Dioxide Hydrate Phase Behavior in Small Porous Silica Gels: Three-Phase Equilibrium Determination and Thermodynamic Modeling

2002

View full text Add to dashboard Cite

Hydrate phase equilibria for the binary CH4 + water and CO2 + water mixtures in silica gel pores of nominal diameters 6.0, 15.0, and 30.0 nm were measured and compared with the calculated results based on van der Waals and Platteeuw model. At a specified temperature, three phase H-LW-V equilibrium curves of pore hydrates were shifted to the higher pressure region depending on pore sizes when compared with those of bulk hydrates. The activities of water in porous silica gels were expressed with a correction term to account for both capillary effect and activity decrease. By using the values of interfacial tension between hydrate and liquid water phases which were recently presented by Uchida et al., 5 the calculation values were in better agreement with the experimental ones. The structure and hydration number of CH4 hydrate in silica gel pores (6.0, 15.0, and 30.0 nm) were found to be identical with those of bulk CH4 hydrate through NMR spectroscopy.

show abstract

Section: Resultsmentioning

confidence: 99%

Methane and Carbon Dioxide Hydrate Phase Behavior in Small Porous Silica Gels: Three-Phase Equilibrium Determination and Thermodynamic Modeling

2002

View full text Add to dashboard Cite

show abstract

“…Peaks such as the minor peak seen here have been observed by using a plethora of different porous materials and confined liquids. [47][48][49][50][51][52][53][54][55][56][57][58][59] The common observation is a minor peak that is assigned to the melting of confined crystals, followed by a major thermal event that is assigned to the melting of bulk crystals. What follows then is an analysis of the assignment of the minor peak to confined water in capillaries of the hydrated gluten network, hence the designation of the minor peak as capillary water, peak cap .…”

Section: Minor Peak Magnificationmentioning

confidence: 97%

Calorimetric and Microstructural Investigation of Frozen Hydrated Gluten

Kontogiorgos

Goff

2006

Food Biophysics

View full text Add to dashboard Cite

The thermal and microstructural properties of frozen hydrated gluten were studied by using differential scanning calorimetry (DSC), modulated DSC, and lowtemperature scanning electron microscopy (cryo-SEM). This work was undertaken to investigate the thermal transitions observed in frozen hydrated gluten and relate them to its microstructure. The minor peak that is observed just before the major endotherm (melting of bulk ice) was assigned to the melting of ice that is confined to capillaries formed by gluten. The Defay-Prigogine theory for the depression of melting point of fluids confined in capillaries was put forward in order to explain the calorimetric results. The pore radius size of the capillaries was calculated by using four different empirical models. Kinetic analysis of the growth of the pore radius size revealed that it follows firstorder kinetics. Cryo-SEM observations revealed that gluten forms a continuous homogeneous and not fibrous network. Results of the present investigation showed that is impossible to assign a T g value for hydrated frozen gluten because of the wide temperature range over which the gluten matrix vitrifies, and therefore the construction of state diagrams is not feasible at subzero temperatures for this material. Furthermore, the gluten matrix is deteriorated with two different mechanisms from ice recrystallization, one that results from the growth of ice that is confined in capillaries and the other from the growth of bulk ice.

show abstract

“…Studies of the change in the melting temperature of liquids for confined geometry were originally performed using Differential Scanning Calorimetry [DSC], and termed thermoporosimetry (Brun et al, 1977;Eyraus et al, 1988;Jallut et al, 1992). However, other techniques for determining the melting features can be used, and NMR relaxation measurements offer a convenient alternative.…”

Section: Nmr Relaxation Diffusion and Cryoporometry Studiesmentioning

confidence: 99%

Structural and dynamic studies of water in mesoporous silicas using neutron scattering and nuclear magnetic resonance

Webber

Dore

2004

J. Phys.: Condens. Matter

View full text Add to dashboard Cite

Abstract. Experimental techniques for studying the behaviour of water in confined geometry using neutron scattering and NMR methods are reviewed. A brief survey is given of earlier work on sol-gel silicas and these findings are updated by reference to current work on MCM-and SBA-type silicas. Particular attention is focused on the phase transitions and the relation between super-cooled water and ice phases in the confined geometry of the mesopores. The characteristics are found to behave in a systematic manner although the nucleation phenomena for partially-filled pores reveals some unexpected complexity for the SBA-silicas.

show abstract

Thermoporometry.

Cited by 27 publications

References 20 publications

Methane and Carbon Dioxide Hydrate Phase Behavior in Small Porous Silica Gels: Three-Phase Equilibrium Determination and Thermodynamic Modeling

Methane and Carbon Dioxide Hydrate Phase Behavior in Small Porous Silica Gels: Three-Phase Equilibrium Determination and Thermodynamic Modeling

Calorimetric and Microstructural Investigation of Frozen Hydrated Gluten

Structural and dynamic studies of water in mesoporous silicas using neutron scattering and nuclear magnetic resonance

Contact Info

Product

Resources

About