Thin film composite membranes were prepared by coating the surface of polyethersulfone ultrafilnation membranes with dilute solutions of sulfonated poly(2,6-dimethyl-1,4-phenylene oxide) polymer. Poly(2,6-dimethyl-1,4-phenylene oxide) was first sulfonated to different degrees, thus obtaining polymers of different ion exchange capacities, from which the coating solutions in methanol or methanol/chloroform mixtures were prepared. The reverse osmosis performance of the thin film composite membranes was studied using electrolyte solutes of different valences and ionic radii. The effect of the solvent used for the preparation of the polymer solution for surface coating was also investigated through testing the performance of the composite membranes in separating different electrolyte solutions as well as by micrographic techniques using a Scanning Electron Microscope and an Atomic Force Microscope. It was found that the preparation of thin film composite membranes with high selectivity and high flux was possible by adjusting properly the ion exchange capacity and the solvent used in making the coating solution. It was also found that the membrane performance was governed primarily by the ion exchange reaction between the solute cation and the proton in-SO$\sb3\sp{-}$H$\sp{+},$ as well as by the Donnan equilibrium. An attempt was also made to investigate the effect of changing the microporous substrate of the thin film composite membrane on the membrane permeation rate and selectivity. The porosity and the structure of the substrate play a significant role in determining the performance of the composit membrane.
| Identifer | oai:union.ndltd.org:uottawa.ca/oai:ruor.uottawa.ca:10393/9576 |
| Date | January 1995 |
| Creators | Hamza, Ali Abdalla. |
| Contributors | Matsuura, T., |
| Publisher | University of Ottawa (Canada) |
| Source Sets | Université d’Ottawa |
| Detected Language | English |
| Type | Thesis |
| Format | 138 p. |
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