This thesis is divided in three sections, all of them focused on a common goal: polymeric membranes. These three sections are: the characterization of membranes, applications of the membranes and the synthesis of new membranes._x000D_ Characterization of membranes is the most extensive section of this memory and has been made with two differentiated perspectives:_x000D_ On one hand, for the first time in the field of membranes, it has been developed the use of the Near Infrared Spectroscopic technique (NIR) as a technique to distinguish the phase inversion membranes, according if they have been prepared by evaporation or by immersion. This developed methodology also allows classifying them by their thickness, just doing a simple near infrared spectrum of the prepared membrane surface and applying a supervised modeling method based on the analysis of residual variance._x000D_ On the other hand, usual techniques have been used for the characterization of membranes such as Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), Electron Spectroscopy for Chemical Analysis (ESCA), Infrared Spectroscopies (IR) or Nuclear Magnetic Resonance (NMR) with the aim of studying the physical properties of the membranes. Specifically, it has been studied in depth three different types of polymeric membranes: polysulfone membranes (PS), polysulfone membranes with a layer of Polyamide (PA), and molecularly imprinted membranes (MIM). In case of PS membranes, the effect of some of the most important variables that affect the formation of macrovoids during their preparation have been determined. These variables are: the membrane thickness, the temperature of the coagulation bath or the presence of other chemical substances such as isopropyl myristate (IPM) used as the carrier agent facilitator. In case of membranes with a layer of PA, it has been performed a surface characterization study, with the aim of take knowledge about the deterioration of these membranes after their use in filtration processes of 40 % of hydrogen peroxide (H2O2) solutions. Finally, the MIM have been characterized, mainly to verify their correct preparation procedure and final formation._x000D_ In the second section, related with membrane applications, both chiral separation of D,L-propranolol and D,L-selenomethionine enantiomers using dialysis systems and, reduction of the Chemical Oxygen Demand (COD) of a 40% hydrogen peroxide solutions using a dead-end filtration system have been considered._x000D_ More specifically, it has been proved that polysulfone membranes prepared by immersion, containing IPM, facilitate the transport of both enantiomers of propranolol, whereas if the compound N-hexadecyl-L-hydroxyproline (HHP) is also added into the membrane, a certain enantioseparation is accomplished. In case of the D,L-selenomethionine enantiomers, it has been proved that the membrane formed by the copolymer N,N-dimethyl-2-aminoethyl methacrylate ̶ ethylenglicol dimethacrylate (DMAEM-EDMA) has the capacity to interact selectively with the L enantiomer of selenomethionine. Regards to COD elimination in H2O2 solutions, it has been proved that polisulfone membranes of nanofiltration with a layer of polyamide can reduce the COD levels from 500 ppm to 62 ppm._x000D_ Finally, the last section about synthesis of new membranes, comprises the synthesis and characterization of new membranes prepared by molecular imprinted technique. It has been used the technique of radical polymerization using benzoin ethyl eter (BEE) as a photoinitiator over a hydrophobic membrane of polyvinylidene fluoride (PVDF-phob, Durapore), using 4 different types of monomers such as 4-vinylpyridine (4VPY), methacrylic acid (MAA), acrylamide (AAM) and N,N-dimethyl-2-aminoethylmethacrylate (DMAEM).
| Date of Award | 24 Jul 2015 |
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| Original language | Catalan |
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| Supervisor | Cristina Palet Ballus (Director) & Tània Gumí Caballero (Director) |
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