Swelling and contraction driven mass transfer processes during osmotic dehydration of uncharged hydrogels
| Autor: | Sigal Eichler, Ory Ramon, Yachin Cohen, Shimon Mizrahi |
|---|---|
| Rok vydání: | 2002 |
| Předmět: |
Chromatography
Chemistry Sodium Polyacrylamide chemistry.chemical_element Industrial and Manufacturing Engineering chemistry.chemical_compound Chemical engineering Mass transfer Sodium citrate Self-healing hydrogels medicine Osmotic pressure Swelling medicine.symptom Food Science Osmotic dehydration |
| Zdroj: | International Journal of Food Science and Technology. 37:245-253 |
| ISSN: | 1365-2621 0950-5423 |
| DOI: | 10.1046/j.1365-2621.2002.00563.x |
| Popis: | The processes of swelling or contraction act as driving forces and thus play important roles in mass transfer during osmotic dehydration of a hydrophilic gel, such as polyacrylamide (PAAm). These driving forces seem to be determined by the interaction between the low molecular solute and the gel polymeric matrix. In a solution of sugars or sodium chloride, the gel undergoes an initial rapid mass loss until it reaches a turning point where the mass transfer process is reversed and the gel swells to a significantly larger extent than in water. However, in solutions of relatively high concentration of sodium citrate or sodium acetate, the gel undergoes only a contraction process and is incapable of regaining any of its lost mass. Empirically, the swelling process follows first order kinetics, which seems to become slower the larger the solution viscosity. |
| Databáze: | OpenAIRE |
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