scholarly journals Concentration dependence of intracrystalline self-diffusion in zeolites

1985 ◽  
Vol 2 (4) ◽  
pp. 229-239 ◽  
Author(s):  
H. Pfeifer ◽  
J. KÄRger ◽  
A. Germanus ◽  
W. Schirmer ◽  
M. BÜLow ◽  
...  

The nmr pulsed field gradient technique is applied to study molecular self-diffusion in zeolitic adsorbate—adsorbent systems. Depending on the zeolite type and on the nature of the adsorbate—adsorbent interaction, the concentration dependence of the self-diffusion coefficients reveals considerable differences. Furthermore, intracrystalline molecular transport may be significantly influenced by the co-adsorption of a second molecular species. Supported by additional nuclear magnetic relaxation and sorption rate measurements microdynamic models for the observed diffusion behaviour are established.

1974 ◽  
Vol 14 (6) ◽  
pp. 915-918
Author(s):  
A. M. Sazonov ◽  
V. M. Olevskii ◽  
A. B. Porai-Koshits ◽  
V. N. Skobolev ◽  
G. A. Shmuilovich

1994 ◽  
Vol 49 (3-4) ◽  
pp. 258-264 ◽  
Author(s):  
D. Girlich ◽  
H.-D. Lüdemann ◽  
C. Buttersack ◽  
K. Buchholz

The self diffusion coefficients D of the water molecules and of sucrose have been determined by the pulsed field gradient NMR technique over a wide range of temperatures and concentrations (cmax: 70% w/w suc.). All temperature dependencies can be fitted to a Vogel- Tammann-Fulcher equation. The isothermic concentration dependence of D for the sucrose is given by a simple exponential concentration dependence


1982 ◽  
Vol 21 ◽  
Author(s):  
H. Bakker

ABSTRACTTheories describing the kinetics of ordered B2 and disordered b.c.c. alloys are applied to the effect of the order-disorder transition on tracer diffusion. Both tracer self-diffusion coefficients and isotope effects in βCuZn and equiatomic FeCo are considered.


Author(s):  
Victor P. Arkhipov ◽  
Natalia A. Kuzina ◽  
Andrei Filippov

AbstractAggregation numbers were calculated based on measurements of the self-diffusion coefficients, the effective hydrodynamic radii of micelles and aggregates of oxyethylated alkylphenols in aqueous solutions. On the assumption that the radii of spherical micelles are equal to the lengths of fully extended neonol molecules, the limiting values of aggregation numbers corresponding to spherically shaped neonol micelles were calculated. The concentration and temperature ranges under which spherical micelles of neonols are formed were determined.


Biopolymers ◽  
2002 ◽  
Vol 63 (2) ◽  
pp. 132-140 ◽  
Author(s):  
Irina V. Nesmelova ◽  
Vladimir D. Skirda ◽  
Vladimir D. Fedotov

2012 ◽  
Vol 1 (6) ◽  
pp. 334-346 ◽  
Author(s):  
Rafik Besbes ◽  
Noureddine Ouerfelli ◽  
Manef Abderabba ◽  
Patric Lindqvist-Reis ◽  
Habib Latrous

1986 ◽  
Vol 41 (7) ◽  
pp. 939-943 ◽  
Author(s):  
E. Hawlicka

The self-diffusion coefficients of Na+, Cl- and I- in methanol-water solutions at 35 ± 0.01 °C have been measured in their dependence on the salt molarity in the range 1 · 10-4- 1 · 10-2 mol dm -3. The ionic self-diffusion coefficients in infinitely diluted solutions have been computed. The influence of the solvent composition on the solvation of the ions is discussed. A preferential hydration of Na+, Cl- and I- ions in water-methanol mixtures has been found.


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