Publicação
Development of thermoresponsive (polysulfone/polyacrylonitrile) - based membranes for bioseparation processes
| dc.contributor.advisor | Ricardo, Ana | |
| dc.contributor.author | Viveiros, Raquel Filipa da Costa | |
| dc.date.accessioned | 2011-07-06T10:51:36Z | |
| dc.date.issued | 2010 | |
| dc.description | Mestrado integrado em Engenharia Química e Bioquímica | en_US |
| dc.description.abstract | In this work it is reported the synthesis of poly(N,N’-diethylacrylamide) (PDEAAm) and the preparation of temperature-responsive polysulfone-based blend membranes using green technologies. The synthesis of the temperature-responsive polymer PDEAAm was studied in supercritical carbon dioxide (scCO2) using different amounts of crosslinker (0 to 2 wt %) and surfactant (0 to 5 wt %). The products of the reactions were characterized by SEM, FT-IR, 1H-NMR, GPC, swelling and turbidimetric measurements. In all reactions, agglomerated polymeric particles were obtained. By increasing the crosslinker ratio in the polymer synthesis, the yield increased from 70 % to 89 %. The lower critical solution temperature (LCST) of synthesized polymers was investigated by turbidimetric measurements and varied in the range 33 - 35 ºC. Polysulfone/polyacrylonitrile (PS/PAN) blend membranes were produced by supercritical carbon dioxide induced phase inversion method. The PAN composition in the blend varied from 0 - 20 wt %. The membranes were characterized in terms of morphology (SEM), porosity (mercury porosimetry), hydrophilicity (contact angle measurements), transport properties (permeability) and mechanical performance (DMA). PS/PAN 9010 membrane showed to have adequate morphological and mechanical characteristics to be coated with temperature-sensitive hydrogels. Thus PS/PAN 9010 membrane was coated by in situ polymerization in scCO2 with two different thermoresponsive polymers, poly(N-isopropylacrylamide) (PNIPAAm) and PDEAAm. Coated membranes were characterized by SEM, X-ray photoelectron spectroscopy (XPS), mercury intrusion porosimetry, DMA, contact angle and water permeability measurements. Contact angle and permeability measurements were performed at 20 and 40 ºC, to investigate the on-off mechanism. Permeation experiments of bovine serum albumin (BSA) and lysozyme (LYS) solutions were performed to evaluate the performance and temperature-responsive behavior of coated membranes. While membranes coated with PNIPAAm presented similar BSA permeation profiles at temperatures below and above its LCST, PDEAAm coating showed a temperature-responsive behavior to PS/PAN 9010 membranes and selective permeation of proteins with different sizes (BSA and LYS). | en_US |
| dc.identifier.uri | http://hdl.handle.net/10362/5900 | |
| dc.language.iso | eng | en_US |
| dc.publisher | Faculdade de Ciências e Tecnologia | en_US |
| dc.title | Development of thermoresponsive (polysulfone/polyacrylonitrile) - based membranes for bioseparation processes | en_US |
| dc.type | master thesis | |
| dspace.entity.type | Publication | |
| rcaap.rights | openAccess | en_US |
| rcaap.type | masterThesis | en_US |