| Autor: |
B. Chaufer, C. Loret, C. Strazielle, Bernard Sebille, S. Candau |
| Rok vydání: |
1988 |
| Předmět: |
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| Zdroj: |
International Journal of Biological Macromolecules. 10:361-365 |
| ISSN: |
0141-8130 |
| DOI: |
10.1016/0141-8130(88)90030-x |
| Popis: |
Commercial samples of gelatin modified by succinylation and currently used as plasma substitutes and fractionated samples obtained by diafiltration have been studied by viscometry, light scattering and osmometry. Viscometric results show that the aqueous medium containing potassium phosphate (0.1 m ) and NaCl (0.12 m ) at pH 3.3 behaves nearly like a theta solvent ( a =0.48) for these modified gelatins. The Stockmayer-Fixman diagram reveals a negative slope attributed to a swelling of the macromolecules which decreases as the molecular weight M w increases. The Stokes radius R H determined by quasielastic light scattering is independent of the pH of the medium in a range 7-3.3. The conformation of gelatins in solution has been characterized through the ratio R G · R H −1 , the radius of gyration R G being determined by viscometry. This ratio decreases as the molecular weight increases. The low molecular weight fractions have a more compact structure than the Gaussian chains in theta conditions. For high molecuar weight fractions, the values of R G · R H −1 tend to those of an hard sphere. |
| Databáze: |
OpenAIRE |
| Externí odkaz: |
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