| Summary: | 碩士 === 嘉南藥理大學 === 環境工程與科學系 === 105 === The purpose of this investigation is focused on the hydrophilic modification of polysulfone(PSF), poly ether imide(PEI), and polysulfone/ poly ether imide membranes on the improvement of separation performance of pervaporation process for dehydration of ethanol/water mixtures. The wet phase inversion method was used to prepare the modified membranes and posted coating poly ethylene imine for hydrophilic enhancement. The hydrophilic properties of modified membranes were tested by water contact angle measurement.
The influent factors on the separation performance of modified membranes were included casting polymer concentration, poly ethylene imine concentration, ionization, feed ethanol concentration and operation temperature in pervaporation process. It was found that the increase in casting polymer concentration increased the skin layer thickness and improved the separation factors of membrane. The optimum prepared polysulfone membrane presented a 267 g/m2hr permeation flux and 334 separation factor. The best poly ethylene imine coating membrane showed a 200 g/m2hr permeation flux and 636 separation factor on pervaporation test. It is worth to noted that those modified membrane will be further increased the separation factor after using the chloride acid ionization. The permeation flux increased with increasing the operation temperature during the PV test due to the enhancement on polymer chain mobility of in the PV process. On the other hand, the feed ethanol concentration on the membrane swelling properties showed the significantly changed the permeation and separation behavior in the PV process. It is concluded that the modification of polyethylene imine coating and ionization exactly increased the hydrophilic of membranes and also improved the separation performance in this investigation.
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