Twenty-five years of thermochemistry research — a personal review

Hill, J.O.

doi:10.1016/0040-6031(92)85114-b

Cited by 3 publications

(2 citation statements)

References 69 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However we consider here for sake of simplification that the freezing and the melting observed is only influenced by the nature of fluid and the pore size. The fact that the crystallization is usually only partial in small pores as shown by Hill is also a reason for which we prefer not to exploit the freezing heat results, since transition enthalpies are probably underestimated . We consider therefore to be in the case where only the fluid−fluid and fluid−wall interactions are predominant, which is reasonable in the case of solid with high energy and polar liquid.…”

Section: Methodsmentioning

confidence: 99%

On the Cation Dependence of Interlamellar and Interparticular Water and Swelling in Smectite Clays

et al. 2010

View full text Add to dashboard Cite

The osmotic character of long-range interlamellar swelling in smectite clays is widely accepted and has been evidenced in the interlayer space by X-ray diffraction. Such a behavior in mesopores was not experimentally confirmed until the determination of the mesopore size distribution in Na-montmorillonite prepared from MX80 bentonite using thermoporometry experiments. This is confirmed here for other montmorillonite samples where the interlayer cations are alkaline and Ca(2+) cations. The nature of the interlayer cation is found as strongly influencing the behavior of the size and the swelling of mesopores. These results are supported by the BJH (Barrett, Joyner and Halenda) pore radius values issued from the nitrogen adsorption-desorption isotherms at the dry state. Thermoporometry results as a function of relative humidity ranging from 11% to 97% have shown an evolution of the mesopore sizes for a purified Na-montmorillonite. New thermoporometry data are presented in this article and confirm that the interparticle spaces in K-, Cs-, or Ca-montmorillonites are not strongly modified for all the range of relative humidity: the swelling is not observed or is strongly limited. It appears in contrast that only Li- and Na-montmorillonites undergo a mesopore swelling, distinct from the interlayer swelling. More generally, our results confirm the possibility to use thermoporometry or differential scanning calorimetry to study the structure and the evolution of swelling materials in wetting conditions such as natural clays or biological cells. In this paper, we describe the different key steps of the hydration of swelling clays such as montmorillonites saturated with alkaline cations. Using thermoporometry results combined with X-ray diffraction data, we distinguish the evolution of the porosity at the two different scales and propose a sequence of hydration dependent on the interlayer cation. From this study, it is shown that the interlayer spaces are not completely filled when the mesopores start to fill up. This implies that the swelling observed in the mesopores for Li and Na samples is due to an osmotic swelling. For the other samples, it is difficult to conclude definitively. Furthermore, we determine the different proportion of water (interlayer water and mesopore water) present in our samples by the original combination of (1) X-ray diffraction data, (2) the pore size distribution obtained by thermoporometry, and (3) recent adsorption isotherm results. It is found that the interlayer space is never completely filled by water at the studied relative humidity values for all samples except for the Cs sample.

show abstract

Section: Methodsmentioning

confidence: 99%

On the Cation Dependence of Interlamellar and Interparticular Water and Swelling in Smectite Clays

et al. 2010

View full text Add to dashboard Cite

show abstract

“…Differential scanning calorimetry is one of the most convenient methods when dealing with phase transitions that involve thermal events such as melting, freezing, allotropic transformation or glass transition [70]. This method measures the temperatures and the heat flow associated with the transitions as a function of time and temperature.…”

Section: Phase Transition Temperatures and Enthalpy Of Meltingmentioning

confidence: 99%

Effects of confinement on freezing and melting

Alba‐Simionesco

Coasne

Dosseh

et al. 2006

J. Phys.: Condens. Matter

780

823

View full text Add to dashboard Cite

We present a review of experimental, theoretical, and molecular simulation studies of confinement effects on freezing and melting. We consider both simple and more complex adsorbates that are confined in various environments (slit or cylindrical pores and also disordered porous materials). The most commonly used molecular simulation, theoretical and experimental methods are first presented. We also provide a brief description of the most widely used porous materials. The current state of knowledge on the effects of confinement on structure and freezing temperature, and the appearance of new surface-driven and confinement-driven phases are then discussed. We also address how confinement affects the glass transition.

show abstract

Chapter 17 Decompositions of coordination compounds

1999

Thermal Decomposition of Ionic Solids

View full text Add to dashboard Cite

Twenty-five years of thermochemistry research — a personal review

Cited by 3 publications

References 69 publications

On the Cation Dependence of Interlamellar and Interparticular Water and Swelling in Smectite Clays

On the Cation Dependence of Interlamellar and Interparticular Water and Swelling in Smectite Clays

Effects of confinement on freezing and melting

Chapter 17 Decompositions of coordination compounds

Contact Info

Product

Resources

About