Adsorption and mobility of water molecules and organic substances in carbon adsorbents 5. Self-diffusion of adsorbed molecules and fractal properties of carbon adsorbents

1989 ◽  
Vol 38 (10) ◽  
pp. 2008-2011
Author(s):  
R. Sh. Vartapetyan ◽  
A. M. Voloshchuk ◽  
J. K�rger ◽  
H. Pfeifer ◽  
W. Heink
Keyword(s):  
Carbon Adsorbents ◽  
Water Molecules ◽  
Organic Substances ◽  
Adsorbed Molecules ◽  
Self Diffusion ◽  
Fractal Properties

The mechanism of the adsorption of water molecules on carbon adsorbents

1995 ◽  
Vol 64 (11) ◽  
pp. 985-1001 ◽  
Author(s):  
R Sh Vartapetyan ◽  
A M Voloshchuk
Keyword(s):  
Carbon Adsorbents ◽  
Water Molecules ◽  
Adsorption Of Water

c , T-Dependence of the Self Diffusion in Concentrated Aqueous Sucrose Solutions

1994 ◽  
Vol 49 (3-4) ◽  
pp. 258-264 ◽  
Author(s):  
D. Girlich ◽  
H.-D. Lüdemann ◽  
C. Buttersack ◽  
K. Buchholz
Keyword(s):  
Field Gradient ◽  
Concentration Dependence ◽  
Diffusion Coefficients ◽  
The Self ◽  
Water Molecules ◽  
Pulsed Field Gradient Nmr ◽  
Pulsed Field ◽  
Self Diffusion ◽  
Sucrose Solutions ◽  
Wide Range

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

The drift self-diffusion of water molecules

1974 ◽  
Vol 14 (6) ◽  
pp. 1032-1033 ◽  
Author(s):  
N. P. Malomuzh ◽  
I. Z. Fisher
Keyword(s):  
Water Molecules ◽  
Self Diffusion

scholarly journals Proton Magnetic Resonance Studies of Water in Slime Mould Plasmodia

1971 ◽  
Vol 24 (3) ◽  
pp. 497 ◽  
Author(s):  
JA Walter ◽  
AB Hope
Keyword(s):  
Relaxation Times ◽  
Bulk Water ◽  
Proton Spin ◽  
Water Molecules ◽  
Signal Pulse ◽  
Cellular Functions ◽  
Slime Mould ◽  
Self Diffusion ◽  
Spin Lattice ◽  
Cytoplasmic Structures

Steady-state and pulse n.m.r. techniques have been applied in a study of water in the cytoplasm of slime mould plasmodia (Ph;ysarum polycephalum). The former method has been used to confirm that the signal detected was from protons in water molecules, and to estimate the fraction of the total water in the sample that was contributing to the observed signal. Pulse techniques have enabled direct measurement of the self-diffusion coefficient D of the bulk water in the cytoplasm, and the proton spin-lattice and spin-spin relaxation times Tl and T2 respectively. The measurements of D can be accounted for if most of the water is in a "free" state, similar to water in a dilute ionic solution, but with a lower value of D due to the obstruction effect of macromolecules and cytoplasmic structures. The values of Tl and T2 indicate that a small "bound" fraction of the water molecules has more restricted motion. The assumption of a two-state model, with exchange of water molecules between "free" and "bound" phases in a time ~ 10-3 sec, yields a representative correlation time T "'" 10-8 sec for the bound fraction. This model is the simplest compatible with all the above results. The underlying assumptions, the extent to which it is likely to be an approximation, and the implications regarding some theories of cellular functions are discussed. Similar results have also been obtained from samples of toad leg muscle, ceils from the meristematic region of pea roots, and from agar and gelatin gels.

scholarly journals Elution Adsorption Dynamics of Organic Substances on Carbon Adsorbents

1993 ◽  
Vol 10 (1-4) ◽  
pp. 173-179 ◽  
Author(s):  
N.S. Polyakov ◽  
A.V. Larin ◽  
M.L. Goubkina
Keyword(s):  
Experimental Data ◽  
Carbon Black ◽  
Breakthrough Curves ◽  
Equilibrium Adsorption ◽  
Carbon Adsorbents ◽  
Organic Substances ◽  
Adsorption Dynamic ◽  
Adsorption Dynamics ◽  
Elution Adsorption Dynamics ◽  
Theoretical Results

Breakthrough curves of CF3Cl on carbon black and of cyclo-hexane on active charcoal have been measured under elution adsorption dynamic conditions. For linear and non-linear adsorption dynamic modes, the experimental data and theoretical results calculated according to the layer of equilibrium adsorption (LEA) model closely coincide.

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