Diffusion coefficient measurements by solvent absorption in concentrated polymer solution
โ Scribed by Charles M. Hansen
- Publisher
- John Wiley and Sons
- Year
- 1981
- Tongue
- English
- Weight
- 264 KB
- Volume
- 26
- Category
- Article
- ISSN
- 0021-8995
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โฆ Synopsis
Abstract
Diffusion coefficient measurements for solvents in concentrated polymer solutions require consideration of both concentration dependence of the diffusion coefficient and surface resistance to mass transport. Solutions to the diffusion equation have been generated where these effects are explored. A method to account for both concentration dependence and surface (absorption) resistance in the experimental determination of diffusion coefficients is given and demonstrated with an example where a multiplying factor of over 300 is required to adjust the apparent diffusion coefficient to the value sought.
๐ SIMILAR VOLUMES
Several versions of free-volume theory have been proposed to correlate or predict the solvent diffusion coefficient of a polymer/solvent system. The quantity of free volume is usually determined by the Williams-Landel-Ferry (WLF) equation from viscosity data of the pure component in these theories.
We determined simultaneously the electrophoretic mobility, diffusion coefficient D and molecular orientation during electrophoresis of dsDNAs in polymer solutions ranging from the dilute to the semidilute regime. We established, for the first time, master scaling laws for the diffusion coefficient s