Activities of Components in the Ca2MgSi2O7-CaSiO3Molten System

1996 ◽  
Vol 61 (6) ◽  
pp. 837-843
Author(s):  
Ladislav Kosa ◽  
Ivan Nerád ◽  
Katarína Adamkovičová ◽  
Jozef Strečko ◽  
Ivo Proks
Keyword(s):  
Gibbs Energy ◽  
Molar Mass ◽  
Excess Entropy ◽  
Enthalpy Of Mixing ◽  
Real Particle ◽  
Entropy Of Mixing ◽  
Energy Of Mixing ◽  
Gibbs Energy Of Mixing

Activities of the components, the Gibbs energy of mixing, and the excess entropy of mixing have been calculated for the Ca2MgSi2O7-CaSiO3 system. The mole fractions of the components were calculated assuming that in the point of the formal component Ca2MgSi2O7, the molar mass of the quasi-real particle in the melt corresponds to its formula molar mass, whereas in the point of the formal component CaSiO3 the molar mass of the quasi-real particle in the melt is 8.5 times higher than as corresponds to its formula. The fact that the enthalpy of mixing is zero whereas the excess entropy of mixing is non-zero suggests that Ca2MgSi2O7-CaSiO3 melts behave as athermal solutions.

scholarly journals Thermodynamic analysis of oligomeric blends by applying the Kirkwood-Buff theory of solutions

2021 ◽  
Vol 2090 (1) ◽  
pp. 012079
Author(s):  
Fotis Venetsanos ◽  
Stefanos D. Anogiannakis ◽  
Doros N. Theodorou
Keyword(s):  
Gibbs Energy ◽  
Thermodynamic Analysis ◽  
Interaction Parameter ◽  
Excess Enthalpy ◽  
Excess Entropy ◽  
Md Simulations ◽  
Liquid Mixtures ◽  
Atomistic Simulations ◽  
Energy Of Mixing ◽  
Gibbs Energy Of Mixing

Abstract The accurate prediction of the thermodynamic properties of oligomeric blends and, in general, binary liquid mixtures from atomistic simulations is a challenging task. In this work we develop a methodology for the full thermodynamic analysis of oligomeric blends and the extraction of the Flory-Huggins interaction parameter from the Gibbs energy of mixing, combining Flory-Huggins thermodynamics with Kirkwood-Buff theory of solutions. We perform a series of Molecular Dynamics (MD) simulations of 2-methylpentane/n-heptane mixtures, at various mole fractions. Firstly we validate the forcefield we apply in our MD simulations, comparing the density and excess volume we obtain against the corresponding experimental estimates found in the literature. Then we calculate the Kirkwood-Buff integrals in the isothermal-isobaric (NpT) ensemble, applying the particle fluctuations method, and we extract the component activity coefficients, the excess Gibbs energy, the excess enthalpy, and the excess entropy of mixing as functions of the mole fraction. Finally we calculate the Flory-Huggins interaction parameter χ by interpreting the Gibbs energy of mixing in the framework of Flory-Huggins theory, and explore its dependence on composition. All results are compared against experimental measurements in order to evaluate our methodology. Agreement is found to be very good.

Calculation of the Gibbs energy of mixing in crystals using Pitzer's model

1994 ◽  
Vol 23 (7) ◽  
pp. 795-812 ◽  
Author(s):  
Chr Christov ◽  
S. Petrenko ◽  
Chr Balarew ◽  
Vl. Valyashko
Keyword(s):  
Gibbs Energy ◽  
Pitzer's Model ◽  
Energy Of Mixing ◽  
Pitzer’S Model ◽  
Gibbs Energy Of Mixing

scholarly journals Modelling thermodynamic properties of binary Cu–Eu and ternary Al–Cu–Eu melts

2020 ◽  
Vol 8 (2) ◽  
pp. 73-82
Author(s):  
Natalia Kotova ◽  
Natalia Golovata ◽  
Natalia Usenko
Keyword(s):  
Thermodynamic Properties ◽  
Gibbs Energy ◽  
Excess Gibbs Energy ◽  
Model Calculations ◽  
Gibbs Energies ◽  
Excess Gibbs Energies ◽  
Energy Of Mixing ◽  
Gibbs Energy Of Mixing ◽  
Associated Solution Model ◽  
Associated Solution

Model calculations of the whole set of thermodynamic properties of liquid alloys for the binary Cu–Eu and ternary Al–Cu–Eu systems have been performed. Authors used the ideal associated solution model (IAS model) for calculation of the entropies and excess Gibbs energies of mixing for these systems. The binaries were given as the Redlich-Kister polynomials. The thermodynamic properties for the ternary system are described using the Redlich-Kister-Muggianu formalism. A comparison of the surfaces of excess Gibbs energy and entropy of mixing for liquid Al–Cu–Eu alloys at 1350 K demonstrates that the ordering related to the formation of rather strong associates in the Al–Eu system significantly affects the concentration dependence of the excess Gibbs energy of mixing in the liquid phase at this temperature.

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