Diffusion in organic liquids. 4. An evaluation of the influence of solvent viscosity and molecular weight on the isotope mass effect for tracer diffusion

1981 ◽  
Vol 85 (7) ◽  
pp. 905-908 ◽  
Author(s):  
Robert Freer ◽  
John N. Sherwood
Keyword(s):  
Molecular Weight ◽  
Mass Effect ◽  
Tracer Diffusion ◽  
Organic Liquids ◽  
Solvent Viscosity ◽  
Influence Of Solvent

Tracer Diffusion of Water in Organic Liquids

1996 ◽  
Vol 41 (4) ◽  
pp. 741-744 ◽  
Author(s):  
Allan J. Easteal
Keyword(s):  
Tracer Diffusion ◽  
Organic Liquids

The Coagulation of Latices by Polar-Nonpolar Liquids

1938 ◽  
Vol 11 (1) ◽  
pp. 87-91
Author(s):  
F. K. Daniel ◽  
H. Freundlich ◽  
K. Söllner
Keyword(s):  
Molecular Weight ◽  
Liquid Phase ◽  
Isoamyl Alcohol ◽  
Isobutyric Acid ◽  
Butyl Alcohol ◽  
Organic Liquids ◽  
Air Bubbles ◽  
Small Molecular Weight ◽  
Gutta Percha ◽  
Nonpolar Liquids

Abstract (1) Diluted latices—Abiarana gutta-percha latex was specially investigated—may be coagulated by shaking them with organic liquids, not miscible with water in all proportions, provided that the liquids form a second liquid phase and that their molecules have a polar-nonpolar structure (butyl alcohol, isobutyric acid, cyclohexanol, etc.). Nonpolar liquids (petroleum ether, chloroform, etc.) do not coagulate diluted latices on shaking under these conditions. (2) This coagulating action can be explained by assuming that the latex particles are strongly accumulated at the interfaces of polar-nonpolar liquids and water; this is not the case with nonpolar liquids. (3) Small concentrations of some polar-nonpolar substances of small molecular weight, soluble in water, can also coagulate Abiarana gutta-percha latex if they form unstable foams; this was observed with propanol and isopropanol. If the foam formed under these conditions is stable, as with small concentrations of dissolved butanol and isobutanol, no coagulation takes place. This behavior can be explained as in (2), the air bubbles behaving like the second liquid phase. (4) Jelutong latex is known to contain an excess of resins, compared with the amount of rubber. A method of coagulating this latex quickly and separating the resins from the rubber consists in shaking the latex for some seconds with certain polar-nonpolar liquids, forming a second liquid phase, such as isobutyl or isoamyl alcohol. A lump of rubber is accumulated at the interface of the two liquids; the resins are contained in the organic phase.

Tracer-Diffusion in Weakly-Ordered Block Copolymers

1989 ◽  
Vol 177 ◽  
Author(s):  
Glenn H. Fredrickson ◽  
Scott T. Milner
Keyword(s):  
Molecular Weight ◽  
Chemical Potential ◽  
Tracer Diffusion ◽  
The Self ◽  
Lamellar Phase ◽  
Radius Of Gyration ◽  
Tracer Diffusion Coefficient ◽  
Spatially Periodic ◽  
Different Molecular Weight ◽  
Diffusion Properties

ABSTRACTWe have investigated the self and tracer-diffusion properties of a labeled diblock copolymer in a weakly-ordered lamellar phase. This phase can be a pure copolymer of equal or different molecular weight, or might contain added homopolymer. The spatially-periodic chemical potential field presented by the lamellar phase is capable of strongly influencing the diffusive motion of the tracer. In general, this field serves to slow diffusion, although the manner in which it acts depends on the wavelength of the potential relative to the labeled copolymer radius-of-gyration and on the composition of the copolymer. In the extreme limit of compositional asymmetry of the diblock tracer, we obtain results for the tracer-diffusion coefficient of a homopolymer.

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