Polymer Partial Enthalpies of Mixing (At Infinite Dilution) or Polymer (First) Integral Enthalpies of Solution

2006 ◽  
pp. 195-350
Author(s):  
Christian Wohlfarth
Keyword(s):  
Infinite Dilution ◽  
First Integral ◽  
Enthalpies Of Solution ◽  
Enthalpies Of Mixing

Differential Enthalpies of Solution of Components in Binary Systems 2 CaO . Al2O3 . SiO2-CaO . Al2O3 . 2 SiO2, CaO . SiO2-CaO . Al2O3 . 2 SiO2 and CaO . SiO2-2 CaO . Al2O3 . SiO2

1993 ◽  
Vol 58 (9) ◽  
pp. 1989-1996 ◽  
Author(s):  
Ladislav Kosa ◽  
Ivan Nerád ◽  
Jozef Strečko ◽  
Ivo Proks ◽  
Katarína Adamkovičová
Keyword(s):  
Binary Systems ◽  
The Other ◽  
Enthalpies Of Solution ◽  
Heat Of Solution ◽  
Differential Heat ◽  
Temperature Range ◽  
Enthalpies Of Mixing ◽  
Other Hand ◽  
Temperature Dependences

Differential enthalpies of solution of components in binary systems 2 CaO . Al2O3 . SiO2-CaO . Al2O3 . 2 SiO2, CaO . SiO2-CaO . Al2O3 . 2 SiO2 and CaO . SiO2-2 CaO . Al2O3 . SiO2 as the function of composition and temperature were determined on the base of isothermal composition dependences of enthalpies of mixing and temperature dependences of heats of fusion of their pure components. From the values of the first differential heat of solution of CaO . Al2O3 . 2 SiO2 and 2 CaO . Al2O3 . SiO2 in CaO . SiO2 over temperature range considered we can conclude that the reactions were closed chains of SiO4 tetrahedra in CaO . SiO2 melt break, are exothermic. On the other hand positive values of this quantity for CaO . SiO2 in CaO . Al2O3 . 2 SiO2 and 2 CaO . Al2O3 . SiO2 led us to the conclusion that the progressive breaking originally closed chains in CaO . SiO2 melt has endothermic character.

Thermochemistry and Structure of Model Waste Glass Compositions

1989 ◽  
Vol 176 ◽  
Author(s):  
Adam J. G. Ellison ◽  
Alexandra Navrotsky
Keyword(s):  
Enthalpies Of Solution ◽  
Charge Balance ◽  
Coordination Polyhedra ◽  
Waste Containment ◽  
Enthalpies Of Mixing ◽  
Heats Of Mixing ◽  
Major Oxide ◽  
Mechanical Mixtures ◽  
End Members ◽  
Glass Compositions

ABSTRACTEnthalpies of mixing of major oxide and waste components of proposed DWPF glasses are estimated. Several proposed glass compositions have very similar molar proportions of major structure-related components. Heats of mixing of major components are predicted to be small (glassy reference states), but may be endothermic or exothermic. Lanthanides are likely to form regions in the glasses rich in R-O-Si bonds but relatively depleted in Si-O-Si bonds. Measured enthalpies of solution of simple lanthanide-bearing glasses resemble those of mechanical mixtures of these end-members, with near-zero enthalpies of mixing for fairly large variations in lanthanide concentrations. DWPF glasses have alkalis in excess of those needed to charge-balance all T3+ cations in tetrahedral coordination. Electropositive +4, +5, and +6 cations are expected to use these excess alkalis to stabilize their own coordination polyhedra, forming complexes with effectively constant macroscopic stoichiometric ratios which contribute to enthalpies of solution in direct proportion to their concentration. Therefore, variations in the concentrations of high-valence cations in DWPF waste containment glasses are also predicted to result in near-zero enthalpies of mixing.

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