Equilibrium decomposition pressures of the compounds Cs2ZrCl6 and Cs2HfCl6 and X-ray identification of Na2HfCl6, K2HfCl6, and Cs2HfCl6

1983 ◽  
Vol 61 (9) ◽  
pp. 2183-2188 ◽  
Author(s):  
G. J. Kipouros ◽  
S. N. Flengas
Keyword(s):  
Vapour Pressure ◽  
Thermodynamic Data ◽  
Pressure Measurements ◽  
Free Energies ◽  
Chemical Equilibria ◽  
X Ray ◽  
Selective Reactivity ◽  
Separating Agents ◽  
Alkali Chlorides

The chemical equilibria representing the reactions[Formula: see text]and[Formula: see text]were investigated by direct vapour pressure measurements and thermodynamic data such as free energies and enthalpies of reaction have been calculated. The X-ray powder patterns of the compounds Na2HfCl6, K2HfCl6, and Cs2HfCl6 are also reported.With reference to the separation of Hf from Zr by a recently developed process based on the selective reactivity of ZrCl4 and HfCl4 vapours with alkali chlorides, it is shown that the efficiency of alkali chlorides as separating agents increases in the order CsCl → LiCl → NaCl → KCl.

Equilibrium decomposition pressures of the compounds Na2ZrCl6 and Na2HfCl6

1981 ◽  
Vol 59 (6) ◽  
pp. 990-995 ◽  
Author(s):  
G. J. Kipouros ◽  
S. N. Flengas
Keyword(s):  
Vapour Pressure ◽  
Thermodynamic Data ◽  
Pressure Measurements ◽  
Free Energies ◽  
Chemical Equilibria ◽  
Selective Reactivity ◽  
Separating Agents ◽  
Alkali Chlorides

The chemical equilibria representing the reactions[Formula: see text]and[Formula: see text]were investigated by direct vapour pressure measurements and thermodynamic data such as free energies and enthalpies of reaction have been calculated.With reference to the separation of Hf from Zr by a recently developed process based on the selective reactivity of ZrCl4 and HfCl4, vapours with alkali chlorides, it is shown that the efficiency of alkali chlorides as separating agents increases in the order of LiCl → NaCl → KCl.

Equilibrium decomposition pressures of the compounds K2ZrCl6 and K2HfCl6

1978 ◽  
Vol 56 (11) ◽  
pp. 1549-1554 ◽  
Author(s):  
G. J. Kipouros ◽  
S. N. Flengas
Keyword(s):  
Vapour Pressure ◽  
Thermodynamic Data ◽  
Pressure Measurements ◽  
Free Energies ◽  
Chemical Equilibria ◽  
Selective Reactivity ◽  
Alkali Chlorides ◽  
Separating Agent

The chemical equilibria representing the reactions[Formula: see text]and[Formula: see text]were investigated by direct vapour pressure measurements. The thermodynamic data for these reactions, such as free energies and enthalpies of reaction, have been calculated. With reference to the separation of Hf from Zr by a recently developed process based on the selective reactivity of ZrCI4 and HfCl4 vapours with alkali chlorides, it is shown that KCl is a better separating agent than LiCl.

Excess free energies of mixing at temperatures below 25°. Isopiestic measurements on the systems H2O-NaCl-Na2SO4 and H2O-NaCl-MgSO4

1971 ◽  
Vol 24 (12) ◽  
pp. 2487 ◽  
Author(s):  
CW Childs ◽  
RF Platford
Keyword(s):  
Free Energy ◽  
Vapour Pressure ◽  
Excess Free Energy ◽  
Pressure Measurements ◽  
Experimental Uncertainty ◽  
Free Energies ◽  
Isopiestic Measurements ◽  
Temperature Range ◽  
Energy Of Mixing ◽  
Free Energy Of Mixing

Isopiestic vapour pressure measurements have been made on the systems H2O-NaCl-Na2SO4 and H2O-NaCl-MgSO4 at 15� and 0�. Excess free energies of mixing the aqueous salts hare been calculated for various ionic strengths, and the results have been compared with those previously obtained at 25�. ��� Within experimental uncertainty the excess free energies of mixing of aqueous NaCl with aqueous Na2SO4 are the same at 0�, 15�, and 25�. However, the excess free energy of mixing aqueous NaCl with aqueous MgSO4 shows differences which may be just larger than experimental uncertainty over the same temperature range.

Thermodynamics of molecular association in binary methanol solutions

1977 ◽  
Vol 30 (6) ◽  
pp. 1241 ◽  
Author(s):  
PP Singh ◽  
BR Sharma ◽  
KS Sidhu
Keyword(s):  
Molecular Species ◽  
Vapour Pressure ◽  
Equilibrium Constants ◽  
Molecular Association ◽  
Pressure Measurements ◽  
Free Energies ◽  
Enthalpy Changes ◽  
Methanol Solutions

This paper deals with isothermal total vapour pressure measurements on methanol (B)+pyridine (A), methanol (B)+β-picoline (A), methanol (B)+N,N-dimethylformamide (A) over the whole range of composition at 303.15 K and the excess Gibbs free energies are evaluated. The data have been analysed in terms of a r-mer-r-mer model of interaction. The equilibrium constants for the various association reactions are evaluated and the enthalpy changes ΔH�l involved in the ABx and A2B molecular species of A and B have also been computed.

Enhancement of Adhesion Between Cu Thin Film and Polyimide Modified by Ion Assisted Reaction

1997 ◽  
Vol 504 ◽  
Author(s):  
S. C. Choi ◽  
K. H. Kim ◽  
H-J. Jung ◽  
C. N. Whang ◽  
S. K. Koha
Keyword(s):  
Ion Irradiation ◽  
Polyimide Film ◽  
Wetting Angle ◽  
Free Energies ◽  
Polyimide Films ◽  
Oxygen Environment ◽  
X Ray ◽  
Oxygen Ion ◽  
Oxygen Gas ◽  
Cu Thin Film

ABSTRACTPolyimide films are modified by ion assisted reaction method using various ion beams in various gases environments. Amount of ion and blown gases rate were changed from 5 × 1014 to 1 × 1017 and from 0 to 8 sccm, respectively. Wetting angles between water and polyimide films modified by Ar+ ion without oxygen blowing decrease from 67° to 400° and surface free energies increase from 46 to 64 dyne/cm2. Wetting angle of polyimide films modified by Ar+ ion in an oxygen environment decreases to 12° and surface free energy increases to 72 dyne/cm2. The lowest wetting angle was obtained by oxygen ion irradiation in the oxygen gas environment and its value was 7°. In the case of polyimide film modified by Ar+ ions in an oxygen environment, the wetting angle increases up to 65° when it kept in air and that increases up to 46° when it kept in water after 5 day. In the case of polyimide film modified by O2+ ion in oxygen environment, however, the wetting angle of polyimide film dose not increase. X-ray photoelectron analysis shows that the chemical bonds between polyimide components are severed by ion irradiation and hydrophilic groups such as CO and C=O are formed by the reaction between newly formed radicals and blown oxygen. It was found that adhesion between Cu and polyimide modified by ion assisted reaction was improved. The main reason of the enhanced adhesion is due to the reaction between Cu and C-O or C=O groups formed by ion assisted reaction on the polyimide surface.

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