Du signal aux phénomènes : une approche pratique pour l’établissement des diagrammes de phases par analyse thermique

The phase diagram of n-Cl~H26 +~-C I S H~~ established by calorimetric and X-ray diffraction analyses exhibits no less than four single phase domains [Tld, [015], [Rils] and [L], two invariants: a eutectic at T = 258.3 K and a metatectic at T= 263.3 K, and five two-phase domains. From a thermodynamic point of view, an interpretation of the phase diagram is given and an attempt is undertaken to modelise the [RI+ L] equilibrium. The extent in composition x of this phase as well as the width in temperature of the [R1 + L] eutectic at x = 1 2, are explained in terms of degree of isomorphism E ;( RI) and excess Gibbs energy functions G (x). Those quantities as well as the melting temperature difference (AT) at x = 1/2, are compared and discussed with other binary systems.

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“…The temperatures are obtained using the form factor method [5]. More details about the methods used are given elsewhere [I, 2, 41.…”

Section: Methodsmentioning

confidence: 99%

Binary Phase Diagram with Non Isomorphous n-Alkanes: C₁₂H₂₆6 – C₁₅H₃₂. Implication of the Rotator Phase R, in the Melting Behaviour of Odd - Even and Even – Odd Phase Diagrams

Espeau

Rajabalee

Haget

1998

Molecular Crystals and Liquid Crystals Science and Technology.

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“…DSC measurements were carried out using a Perkin-Elmer DSC7 differential scanning calorimeter [20,21]. The random part of the uncertainties was estimated using the Student's method with 95% threshold of reliability.…”

Section: Dsc Measurementsmentioning

confidence: 99%

pVT Measurements and Related Studies on the Binary System nC₁₆H₃₄ -nC₁₇H₃₆ and on nC₁₈H₃₈ at High Pressures

Würflinger

Mondieig²,

Rajabalee³

et al. 2001

Zeitschrift Für Naturforschung A

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The phase diagram of the binary system nC16H34 -rcC17H36 has been established at ambient pressure using DSC and crystallographic measurements. At low temperatures below the rotator phase RI there exist two crystal forms Op (about jc(C17) = 0.25) and Mdci (about x(C17) = 0.67) which are different from the crystal structures of the pure compounds (Tp for C 16 and Oi for C 17). Furthermore two compositions: (a) C 16/C 17 = 3:1 and (b) = 1:2, which correspond to the coexistence range of Op and Mdci, were chosen for high pressure DTA and pVT measurements, yielding the following findings: The specific volume of the rotator phase of C 17 is distinctly lower than those of the binary systems at the same state point. Assuming the existence of a metastable rotator phase for C 16, an excess volume of A V E/V « 0.01 can be estimated. Due to the very enlarged coexistence range of RI, the mixtures reach their lower transition point at considerably lower temperatures (in isobaric measurements) or higher pressures (in isothermal measurements), where the specific volume is lower than that of C 17 at its transition point. Furthermore, the volume and enthalpy changes of the O ord -RI transition is distinctly smaller for the binary systems than for pure C 17. Thus the specific volumes of the phases Op and Mdci are appreciably larger than t>(spec.) of C 17. Op and Mdci have practically the same specific volume in accordance with the crystallographic results. Enthalpy values are obtained with the aid of the Clausius-Clapeyron equation which agree well with enthalpies derived from the DSC measurements.Furthermore, pVT data have been established for the liquid and solid phases of nC18H38 in the neighbourhood of the melting curve, allowing to determine volume and enthalpy changes of melting as a function of pressure.

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“…sured using the DSC were determined, from the original thermograms, using the shape factor method (33,34 rized in Table 4.…”

Section: Function Of the Mole Fraction Of Pementioning

confidence: 99%

Molecular Interactions and Packing in Molecular Alloys between Nonisomorphous Plastic Phases

López

Tamarit

Négrier³

et al. 1996

Journal of Solid State Chemistry

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Du signal aux phénomènes : une approche pratique pour l’établissement des diagrammes de phases par analyse thermique

Cited by 43 publications

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Binary Phase Diagram with Non Isomorphous n-Alkanes: C₁₂H₂₆6 – C₁₅H₃₂. Implication of the Rotator Phase R, in the Melting Behaviour of Odd - Even and Even – Odd Phase Diagrams

Binary Phase Diagram with Non Isomorphous n-Alkanes: C₁₂H₂₆6 – C₁₅H₃₂. Implication of the Rotator Phase R, in the Melting Behaviour of Odd - Even and Even – Odd Phase Diagrams

pVT Measurements and Related Studies on the Binary System nC₁₆H₃₄ -nC₁₇H₃₆ and on nC₁₈H₃₈ at High Pressures

Molecular Interactions and Packing in Molecular Alloys between Nonisomorphous Plastic Phases

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Du signal aux phénomènes : une approche pratique pour l’établissement des diagrammes de phases par analyse thermique

Cited by 43 publications

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Binary Phase Diagram with Non Isomorphous n-Alkanes: C12H266 – C15H32. Implication of the Rotator Phase R, in the Melting Behaviour of Odd - Even and Even – Odd Phase Diagrams

Binary Phase Diagram with Non Isomorphous n-Alkanes: C12H266 – C15H32. Implication of the Rotator Phase R, in the Melting Behaviour of Odd - Even and Even – Odd Phase Diagrams

pVT Measurements and Related Studies on the Binary System nC16H34 -nC17H36 and on nC18H38 at High Pressures

Molecular Interactions and Packing in Molecular Alloys between Nonisomorphous Plastic Phases

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Binary Phase Diagram with Non Isomorphous n-Alkanes: C₁₂H₂₆6 – C₁₅H₃₂. Implication of the Rotator Phase R, in the Melting Behaviour of Odd - Even and Even – Odd Phase Diagrams

Binary Phase Diagram with Non Isomorphous n-Alkanes: C₁₂H₂₆6 – C₁₅H₃₂. Implication of the Rotator Phase R, in the Melting Behaviour of Odd - Even and Even – Odd Phase Diagrams

pVT Measurements and Related Studies on the Binary System nC₁₆H₃₄ -nC₁₇H₃₆ and on nC₁₈H₃₈ at High Pressures