Mixed matrix membranes (MMMs) consisting of a polymer bulk phase and an inorganic dispersed phase have the potential to provide a more selective membrane because they incorporate the selectivity of a zeolite dispersed phase while maintaining the ease of use of a polymer membrane. A critical problem in MMM applications is control over the polymer-zeolite interface adhesion during fabrication which can detrimentally impact membrane performance. In this work, MgOxHy (1≤x≤2, 0≤y≤2) nanostructures have been grown on pure-silica MFI and aluminosilicate LTA zeolites through four surface deposition techniques: Grignard decomposition reactions, solvothermal and modified solvothermal depositions, and ion-exchange induced surface crystallization. The structural properties of the surface nanostructures produced by each of the four methods were thoroughly characterized for their morphology, crystallinity, porosity, surface area, elemental composition, and these properties were used to predict the method’s suitability for use in composite membranes. The nanostructured zeolites were used in mixed matrix membranes (MMMs) at two MMMs weight loadings. The dispersion, mechanical properties, and CO₂/CH₄ gas separation properties were measured MMMs made with each method of functionalized LTA. All functionalization methods improve adhesion with the polymer observable by microscopy, the dispersion of particles, and the elastic modulus and hardness of the membrane. Gas permeation measurements prove the quality and effectiveness of the Ion Exchange membrane for CO₂/CH₄ separation by its significant increase in selectivity over the pure polymer. Lastly, the interface between the two materials was studied by probing the interfacial polymer mobility using NMR spin-spin relaxation measurements and mechanical mapping of membrane cross sections. It was shown that the nanostructures have both steric and chemical interactions with the polymer. Mapping of the elastic modulus indicated that functionalization methods that resulted in poorer zeolite coverage also disrupted the mechanical properties of the membrane at the interface of the materials. The investigations in this thesis provide detailed structure-property relationships of surface-modified molecular sieves and nanocomposite membranes fabricated using these materials, allowing a rational approach to the design of such materials and membranes.

La séparation CO2/N2 et H2/CO2 permet de limiter le rejet de CO2 dans l’atmosphère issu des gaz industriels et les membranes présentent de nombreux avantages tant sur le plan économique que pratique. Les membranes polymère sont faciles à mettre en forme mais un compromis entre perméabilité et sélectivité doit généralement être trouvé : pour améliorer les performances, des membranes à matrice mixte (MMM) incorporant des MOFs (matériaux hybrides poreux cristallisés) dispersés dans la phase polymère ont été proposées. A la différence des matériaux poreux inorganiques, les MOFs ont une meilleure compatibilité avec la matrice polymère du fait de leur caractère hybride organiqueinorganique. Dans le cadre de cette thèse, des polycarboxylates de Fe3+ et Al3+ poreux, stables à l’eau, et possédant de bonnes propriétés d’adsorption sélective du CO2 ont été synthétisés en milieu aqueux et mis à l’échelle de quelques grammes. Deux nouveaux polycarboxylates de Fe3+ poreux fonctionnalisés par des fonctions -COOH libres ont été obtenus à température ambiante. Pour l’un d’entre eux, la structure a été déterminée par diffraction des rayons X. Une deuxième partie de la thèse a été consacrée à la synthèse de nanoparticules de MOFs avec un bon rendement. Une partie importante de ce travail a porté sur le contrôle de la taille et la morphologie des nanoparticules de MIL-96(Al). Ce travail a conduit à la préparation de MMMs à base de MIL-96(Al) dont les performances sont supérieures à la membrane pure polymère pour la séparation CO2/N2. La dernière partie de ce travail de thèse a porté sur l’étude physico-chimique de la compatibilité entre le ZIF-8 et deux polymères (PVA et PIM-1). Ce travail a consisté à effectuer une caractérisation complète de solutions colloïdales MOFs/polymère en couplant plusieurs techniques (DLS, TEM, SAXS). Cette étude a montré que la compatibilité MOF/polymère est très dépendante de la chimie de surface des MOFs et des propriétés physico-chimiques du polymère (rigidité, caractère hydrophile/hydrophobe…). / CO2 capture and storage (CCS) is of high economical and societal interest. CO2/N2 andH2/CO2 separations are able to limit atmospheric CO2 emissions produced by industrial exhausts andmembranes present numerous economical and practical advantages. Polymer membranes are easy toprocess and possess interesting mechanical properties. However, there is a trade-off to make betweenpermeability and selectivity. Mixed-matrix membranes (MMM) based on MOFs (porous crystallinehybrid materials) have been proposed to boost the performances of polymer membranes for CO2capture. In comparison to other inorganic porous materials, one may expect that the compatibilitybetween MOFs and polymers is enhanced due to the hybrid character of MOFs.In this work, porous water stable polycarboxylate MOFs based on Fe3+ and Al3+ with promisingproperties for CO2 adsorption were synthesized for large-scale production using water as the mainsolvent. Two new porous polycarboxylate Fe3+ MOF bearing free -COOH groups in the frameworkwere obtained at room temperature as nanoparticles. The crystallographic structure of one of thesematerials was determined by single crystal X-ray diffraction. A second part of the thesis was devotedto the synthesis of MOFs nanoparticles with good yield. We focused our attention on the control of thediameter and morphology of MIL-96(Al) nanoparticles. This study led to the preparation of MMMsbased on MIL-96(Al) with promising properties for CO2/N2 separation. Finally, the compatibilitybetween MOF particles and polymers was studied for two systems (ZIF-8/PIM-1 and ZIF-8/PVOH),showing the influence of the surface chemistry of MOFs and the physico-chemical properties ofpolymer on the matching between MOFs and polymers.

Polymeric membranes exhibit a trade-off between permeability and selectivity in gas separations which limits their viability as an economically feasible post-combustion carbon capture technology. One approach to improve the separation properties of polymeric membranes is the inclusion of particulate materials into the polymer matrix to create what are known as mixed matrix membranes (MMMs). By combining the polymer and particulate phases, beneficial properties of both can be seen in the resulting composite material. One of the most notable challenges in producing mixed matrix membranes is in the formation of performance-hindering defects at the polymer-filler interface. Non-selective voids or polymer chain rigidification are but two non-desirable effects which can be observed. The material selection and synthesis route are key to minimising these defects. Thin membranes are also highly desirable to achieve greater gas fluxes and improved economical separation processes. Hence smaller nano-sized particles are of particular interest to minimise the disruption to the polymer matrix. This is a challenge due to the tendency of some small particles to form agglomerations. This work involved introducing novel nanoscale filler particles into PEBAX MH1657, a commercially available block-copolymer consisting of poly(ethylene oxide) and nylon 6 chains. Poly(ether-b-amide) materials possess an inherently high selectivity for the CO2/N2 separation due to polar groups in the PEO chain but suffer from low permeabilities. Mixed matrix membranes were fabricated with PEBAX MH1657 primarily using two filler particles, nanoscale ZIF-8 and novel nanoscale MCM-41 hollow spheres. This work primarily investigated the effects of the filler loading on both the morphology and gas transport properties of the composite materials. The internal structure of the membranes was examined using scanning electron microscopy (SEM), and the gas transport properties determined using a bespoke time-lag gas permeation apparatus. ZIF-8 is a zeolitic imidazolate framework which possesses small pore windows that may favour CO2 transport over that of N2. ZIF-8-PEBAX membranes were successfully synthesised up to 7wt.%. It was found that for filler loadings below 5wt.%, the ZIF-8 was well dispersed within the polymer phase. At these loadings modest increases in the CO2 permeability coeffcient of 0-20% compared to neat PEBAX were observed. Above this 5wt.% loading large increases in both CO2, N2 and He permeability coeffcients coincided with the presence of large micron size clusters formed of hundreds of filler ZIF-8 particles. The increases in permeability were attributed to voids observed within the clusters. MCM-41 is a metal organic framework that has seen notable interest in the field of carbon capture, due to its tunable pore size and ease of functionalisation. Two types of novel MCM-41 hollow sphere (MCM-41-HS) of varying pore size were incorporated into PEBAX and successfully used to fabricate MMMs up to 10wt.%. SEM showed the MCM-41 generally interacted well with the polymer with no signs of voids and was generally well dispersed. However, some samples of intermediate loading in both cases showed highly asymmetric distribution of nanoparticles and high particle density regions near one external face of the membrane which also showed the highest CO2 permeability coeffcients. It is suspected that these high permeabilities are due to the close proximity of nanoparticles permitting these regions to act in a similar way to percolating networks. It was determined that there was no observable effect of the varying pore size which was expected given the transport in the pores should be governed by Knudsen diffusion.

Mixed matrix hollow fiber membranes maintain the ease of processing polymers while enhancing the separation performance of the pure polymer due to inclusion of molecular sieve filler particles. This work shows the development process of high loading mixed matrix hollow fiber membranes for butane isomer separation, from material selection and engineering of polymer-sieve interfacial adhesion to mixed matrix hollow fiber spinning. The matching of gas transport properties in polymer and zeolite is critical for forming successful mixed matrix membranes. The nC4 permeability in glassy commercial polymers such as Ultem® and Matrimid® is too low (< 0.1 Barrer) for commercial application. A group of fluorinated (6FDA) polyimides, with high nC4 permeability and nC4/iC4 selectivity, are selected as the polymer matrix. No glassy polymers can possibly match the high permeable MFI to make mixed matrix membranes with selectivity enhancement for C4s separation. Zeolite 5A, which has a nC4 permeability (~3 Barrer) and nC4/iC4 selectivity (essentially ∞), matches well with the 6FDA polymers. A 24% nC4/iC4 selectivity enhancement was achieved in mixed matrix membranes containing 6FDA-DAM and 25 wt% treated 5A particles. A more promising mixed matrix membrane contains 6FDA-DAM-DABA matrix and 5A, because of a better match of gas transport properties in polymer and zeolite. Dual layer hollow fibers, with cellulose acetate core layer and sheath layers of 6FDA polyimides, were successfully fabricated. Successive engineering of the 6FDA sheath layer and the dense skin is needed for the challenging C4s separation, which is extremely sensitive to the integrity of the dense skin layer. The delamination-free, macrovoid-free dual layer hollow fiber membranes provide the solution for the expensive 6FDA polyimides spinning. Mixed matrix hollow fiber membranes are spun base on the platform of 6FDA/Cellulose acetate dual layer hollow fibers. Preliminary results suggest that high loading mixed matrix hollow fiber membranes for C4s is feasible. Following research is needed on the fiber spinning with well treated zeolite 5A nanoparticles. The key aspect of this research is elucidating the three-step (sol-gel-precipitation) mechanism of sol-gel-Grignard treatment, based on which further controlling of Mg(OH)2 whisker morphologies is possible. A Mg(OH)2 nucleation process promoted by acid species is proposed to explain the heterogeneous Mg(OH)2 growing process. Different acid species were tried: 1) HCl solution, 2) AlClx species generated by dealumination process and 3) AlCl3 supported on zeolite surfaces. Acids introduced through HCl solution and dealumination are effective on commercial 5A particles to generate Mg(OH)2 whiskers in the sol-gel-Grignard treatment. Supported AlCl3 is effective on both commercial and synthesized 5A particles (150 nm-1 µm) during the sol-gel-Grignard treatment, in terms of promoting heterogeneous Mg(OH)2 whiskers formation. But the byproduct of Al(OH)3 layer separates the Mg(OH)2 whiskers from zeolite surface, and leads to undesirable morphologies for polymer-zeolite interfacial adhesion. The elucidation of sol-gel-Grignard mechanism and importance of zeolite surface acidity on Mg(OH)2 formation, builds a solid foundation for future development towards ''universal'' method of growing Mg(OH)2 whiskers on zeolite surfaces.

Dans le cadre de la réduction des émissions de gaz à effet de serre, une des approches possibles consiste en l’utilisation de membranes pour séparer le CO2 de mélanges gazeux. Durant ce travail de thèse, la séparation CO2 / N2 dans des conditions de post-combustion a été étudiée pour des membranes à matrice mixte composées de matériaux organométalliques poreux, les MOF, insérés dans des polymères. Plus spécifiquement, la thèse porte sur la caractérisation de ces membranes à l’aide des spectroscopies vibrationnelles (IR et Raman). Différentes membranes polymériques et membranes à matrice mixte basées sur des polymères commerciaux comme le Matrimid ou le PEBAX ou des nouveaux polymères comme le PIM-1 ou 6FDA-DAM plus performants ont ainsi été étudiées. La spectroscopie Raman a d’abord été utilisée pour contrôler l’homogénéité des membranes et la bonne dispersion du MOF au sein du polymère à l’aide du Raman. Les interactions entre le polymère et le MOF ont également été étudiées à l’aide des spectroscopies IR in situ et Raman, notamment pour des composites modèles permettant de maximiser les interactions entre les deux composés. La deuxième partie du travail a été axée sur la caractérisation spectroscopique (IR operando) de ces membranes dans les conditions de post-combustion, simultanément à la mesure de leurs performances en séparation. Un système de mesures dédié a donc été spécialement développé. Cette méthodologie permet de comparer directement les données d’adsorption et de séparation des membranes. En développant une nouvelle approche couplant les aspects cinétiques et thermodynamiques de l’adsorption et de la perméation, les données expérimentales ont été modélisées afin de déterminer les paramètres d’adsorption et de diffusion des différentes membranes. / In the frame of the abatement of greenhouse gases, one of the possible approaches concern the use of membranes to separate CO2 from gas mixtures. During this PhD work, CO2 / N2 separation in post-combustion conditions has been studied for Mixed Matrix Membranes constituted by porous organometallic materials, MOFs, inserted into polymers. More specifically, this work aims at the characterization of these membranes using vibrational spectroscopies (IR and Raman). Different membranes, purely polymeric or Mixed Matrix Membranes, based on commercial polymers such as Matrimid or PEBAX as well as new polymers such as PIM-1 or 6FDA-DAM have been studied. Raman spectroscopy was first used to control the homogeneity of the membranes and the good dispersion of the MOF within the polymer. The interactions between the polymer and the MOF were also studied using IR in situ and Raman spectroscopies, notably for composites allowing maximizing the interactions between the two components. The second part of the work focused on the characterization of these membranes under operating post-combustion conditions, simultaneously with the measurement of their separation performance. For this purpose, a specifically designed measurement system has been developed in order to be able to test the membranes using IR operando. This methodology allows the direct comparison of adsorption and separation data. By the development of a new approach coupling kinetic and thermodynamic aspects of adsorption and permeation, experimental data were modelled to determine adsorption and diffusion parameters of the various membranes.

No description available.

Η παρούσα διδακτορική διατριβή αποτελείται από δύο ξεχωριστές ενότητες οι οποίες έχουν σαν στόχο τη μελέτη τροποποιημένων πολυμερικών μεμβρανών για χρήση σε κυψελίδες καυσίμου αγωγής πρωτονίων και σε εφαρμογές διαχωρισμού αερίων. Στην πρώτη ενότητα έγινε εκτίμηση του μοριακού προσανατολισμού μονοαξονικά εφελκυσμένων πολυμερικών μεμβρανών Nafion-115 με τη βοήθεια πολωμένων φασμάτων UV-Raman. Πειράματα δυναμικής μηχανικής ανάλυσης επαλήθευσαν τις προσδοκίες για βελτίωση των μηχανικών ιδιοτήτων του πολυμερικού ηλεκτρολύτη κατά μήκος της διεύθυνσης εφελκυσμού. Η θερμική ανάλυση των δειγμάτων με τις τεχνικές της διαφορικής θερμιδομετρίας σάρωσης και της θερμοσταθμικής ανάλυσης δεν έδειξε κάποια ιδιαίτερη διαφοροποίηση μεταξύ εφελκυσμένων και μη δοκιμίων Nafion-115, πέραν της βελτίωσης της ικανότητας των τανυσμένων μεμβρανών να συγκρατούν το όποιο νερό υπάρχει στο ιονομερές. Μικρή ήταν η αύξηση της ιοντικής αγωγιμότητας που παρατηρήθηκε στα τανυσμένα δείγματα κατά μήκος της διεύθυνσης εφελκυσμού. Η προσπάθεια τροποποίησης του Nafion® με διαξονικό εφελκυσμό είχε σαν αποτέλεσμα τη λήψη λεπτών πολυμερικών ηλεκτρολυτικών μεμβρανών με αποτελεσματικότερες ιδιότητες στην τάση διέλευσης της μεθανόλης, σε σχέση με τις μη τροποποιημένες μεμβράνες. Επιπρόσθετα, με τον ελεγχόμενο διαξονικό και σταθερού πλάτους μονοαξονικό εφελκυσμό κατέστη δυνατό να επιτευχθεί η εξισορρόπηση των ποσοστών διαστολής κατά το μήκος και πλάτος της επιφάνειας του Nafion, μετά τον εμποτισμό του με νερό. Όσον αφορά στην τροποποίηση του Nafion με εναπόθεση στοιβάδας αγώγιμου πολυμερούς πολυανιλίνης (PAni) ή πολυπυρρόλης (PPy) με ενσωματωμένα αντισταθμιστικά ιόντα SO42- ή Nafion-, η φασματοσκοπική μελέτη, μέσω ATR-FTIR, σε συνδυασμό με τις μικροφωτογραφίες SEM που ελήφθησαν, οδήγησαν στα εξής συμπεράσματα: Για τις σύνθετες μεμβράνες Nafion/PAni που παρασκευάστηκαν με την τεχνική της διάχυσης, από τη μία ελήφθησαν δείγματα με ικανοποιητική συνάφεια μεταξύ του κυρίως όγκου της πολυμερικής μεμβράνης Nafion και της PAni, από την άλλη όμως, υπάρχει και κάποιο ποσοστό μονομερούς ανιλίνης (Ani) που εγκλωβίζεται στο εσωτερικό του Nafion, και μάλιστα σε σημαντικό βαθμό, που εξαρτάται από το χρόνο σύνθεσης. Αντίθετα, οι αντίστοιχες μελέτες στις μεμβράνες Nafion/PPy δε φανερώνουν την ύπαρξη διείσδυσης της PPy ή του μονομερούς στην κύρια μάζα του Nafion, ή τουλάχιστον όχι σε τέτοιο βαθμό που να μπορεί να ανιχνευθεί μέσω της τεχνικής που χρησιμοποιήθηκε. Ιδιαίτερο είναι το ενδιαφέρον που προκύπτει από τις φασματοσκοπικές μετρήσεις στην πλευρά του σύνθετου πολυμερούς όπου εναποτίθετο το πολυμερισμένο αγώγιμο υλικό, καθώς με το χρόνο σύνθεσης παρατηρούνται μετατοπίσεις κορυφών του Nafion προς χαμηλότερες συχνότητες, υποδεικνύοντας ενδεχόμενη αλληλεπίδραση με το αγώγιμο πολυμερές. Στη δεύτερη ενότητα μελετήθηκαν οι σύνθετες (ή “mixed matrix”) πολυμερικές μεμβράνες πολυσουλφόνης (PSF) με ενσωματωμένες φυλλώδεις αργυλοφωσφορικές νανονιφάδες τύπου AlPO. Αρχικά πραγματοποιήθηκε η σύνθεση των νανονιφάδων AlPO. Με στόχο τη βελτίωση της συμβατότητάς τους με την πολυμερική μήτρα έγινε παρεμβόλιση με κατάλληλη επιφανειοδραστική ουσία και χαρακτηρισμός με XRD που έδειξε τη διεύρυνση της απόστασης μεταξύ των διαδοχικών στρωμάτων του κρυστάλλου από 9Å σε 33Å περίπου. Στη συνέχεια παρασκευάσθηκαν οι σύνθετες μεμβράνες με διαφορετικές συγκεντρώσεις της ανόργανης φάσης, με τη μέθοδο του film casting. Με βάση τις εικόνες SEM οι νανονιφάδες φαίνεται να έχουν ικανοποιητική διασπορά στη μάζα της πολυσουλφόνης, ενώ τα φάσματα XRD δείχνουν πως η ενσωμάτωση των παρεμβολισμένων νανονιφάδων στην πολυμερική μήτρα δεν επέφερε κάποια σημαντική αλλαγή στη δομή τους. Οι νανονιφάδες, ακόμα και σε μικρές συγκεντρώσεις, βελτιώνουν σε σημαντικό βαθμό τη διαχωριστική ικανότητα των αμιγώς πολυμερικών μεμβρανών για τα ζεύγη αερίων H2/N2 και Η2/CH4 όχι όμως και για το ζεύγος Η2/CO2. Αντίθετα, η αύξηση του ποσοστού των νανονιφάδων AlPO οδηγεί σε μείωση της διαπερατότητας του H2. Oι σύνθετες μεμβράνες PSF/AlPO δείχνουν μια μικρή βελτίωση του μέτρου ελαστικότητας αποθηκευόμενης ενέργειας σε σχέση με τις πολυμερικές μεμβράνες PSF, εμφανίζουν επίσης ελαφρώς μειωμένη θερμοκρασία υαλώδους μετάβασης και, κατά τη θέρμανσή τους, ακολουθούν τρία στάδια απώλειας μάζας λόγω αποσύνθεσης της επιφανειοδραστικής ουσίας σε συνδυασμό με απώλεια φυσικά και χημικά ροφημένου νερού. / The present thesis consists of two separate parts which focus on the study of modified polymer membranes for use in fuel cells applications and gas separation processes. In the first part, the molecular orientation of uniaxially drawn Nafion-115 membranes was estimated utilizing polarized UV-Raman spectra. Dynamic mechanical analysis revealed the enhanced strength of the drawn samples along the draw axis. Thermal analysis, carried out via differential scanning calorimetry, and thermogravimetric analysis did not show any difference between drawn and undrawn specimens, except from a slight enhanced capability of the drawn membranes to water content retain. Proton conductivity is slightly enhanced along the stretching direction, as well. The attempts for biaxial stretching of Nafion® had as a result the production of very thin polymer electrolyte membranes with lower permeability to methanol than the commercial one. In addition, with biaxial and constant width uniaxial stretching, the swelling of Nafion along and across its surface can be controlled. The process of modifying Nafion by embedding conducting polymer layers of polypyrrole or polyaniline with SO42- or Nafion- incorporated into the film as counter-ions is studied via ATR-FTIR spectroscopy in combination with SEM microphotographs. Nafion/PAni composite membranes synthesized by the diffusion method showed very good adherence between Nafion and PAni layers but it seems that there is some Ani monomer still remaining inside the bulk structure of Nafion, depending on the time of synthesis. In contrast, the corresponding studies on Nafion/PPy membranes show that there is no penetration of PPy or Py inside Nafion, at least not to the extent that it could be traced using ATR-FTIR spectroscopy. The spectroscopic measurements from the conducting polymer side show red-shifts of absorption bands of Nafion revealing possible specific interactions with the conducting polymer. In the second part, composite (or mixed matrix) polymeric membranes with dispersed aluminophosphate nanoflakes were studied. At the beginning AlPO nanoflakes were synthesized. To enhance the compatibility with the polymer matrix conventional AlPO nanoflakes were intercalated using suitable surfactant. XRD characterization showed a further individual layers` separation since the distance between them is increased from 9Å to 33Å. Subsequently, mixed matrix membranes with different nanoflakes loading were synthesized, using film casting method. Based on SEM images nanoflakes seem to be well dispersed in the mass of polysulfone, while XRD graphs implied that the incorporation of intercalated nanoflakes into the polymer matrix did not affect their structural characteristics. Nanoflakes incorporation, even at very low concentrations, improves the H2/N2 and H2/CH4 selectivity and deteriorates the H2/CO2 selectivity compared with the pure polymer. On the other hand, the higher the percentage of the AlPO flakes, the more pronounced the decrease in hydrogen permeability. PSF/AlPO membranes exhibit improved storage modulus, appear to have slightly lower glass transition temperature compared with PSF membranes and during their heating, follow a three steps mass loss due to the surfactant decomposition and the loss of physically and chemically absorbed water.

[ES] La presente tesis doctoral se centra en el desarrollo de nuevas membranas de separación de gases, así como su empleo in-situ en reactores catalíticos de membrana para la intensificación de procesos. Para este propósito, se han sintetizado varios materiales, como polímeros para la fabricación de membranas, catalizadores tanto para la metanación del CO2 como para la reacción de síntesis de Fischer-Tropsch, y diversas partículas inorgánicas nanométricas para su uso en membranas de matriz mixta. En lo referente a la fabricación de las membranas, la tesis aborda principalmente dos tipos: orgánicas e inorgánicas. Con respecto a las membranas orgánicas, se han considerado diferentes materiales poliméricos, tanto para la capa selectiva de la membrana, así como soporte de la misma. Se ha trabajado con poliimidas, puesto que son materiales con temperaturas de transición vítrea muy alta, para su posterior uso en reacciones industriales que tienen lugar entre 250-300 ºC. Para conseguir membranas muy permeables, manteniendo una buena selectividad, es necesario obtener capas selectivas de menos de una micra. Usando como material de soporte otro tipo de polímero, no es necesario estudiar la compatibilidad entre ellos, siendo menos compleja la obtención de capas finas. En cambio, si el soporte es de tipo inorgánico, un exhaustivo estudio de la relación entre la concentración y la viscosidad de la solución polimérica es altamente necesario. Diversas partículas inorgánicas nanométricas se estudiaron para favorecer la permeación de agua a través de los materiales poliméricos. En segundo lugar, en cuanto a membranas inorgánicas, se realizó la funcionalización de una membrana de paladio para favorecer la permeación de hidrógeno y evitar así la contaminación por monóxido de carbono. El motivo por el cual se dopó con otro metal la capa selectiva de la membrana metálica fue para poder emplearla en un reactor de Fischer-Tropsch. Con relación al diseño y fabricación de los reactores, durante esta tesis, se desarrolló el prototipo de un microreactor para la metanación de CO2, donde una membrana polimérica de capa fina selectiva al agua se integró para evitar la desactivación del catalizador, y a su vez desplazar el equilibrio y aumentar la conversión de CO2. Por otro lado, se rediseñó un reactor de Fischer-Tropsch para poder introducir una membrana metálica selectiva a hidrogeno y poder inyectarlo de manera controlada. De esta manera, y siguiendo estudios previos, el objetivo fue mejorar la selectividad a los productos deseados mediante el hidrocraqueo y la hidroisomerización de olefinas y parafinas con la ayuda de la alta presión parcial de hidrógeno. / [CAT] La present tesi doctoral es centra en el desenvolupament de noves membranes de separació de gasos, així com el seu ús in-situ en reactors catalítics de membrana per a la intensificació de processos. Per a aquest propòsit, s'han sintetitzat diversos materials, com a polímers per a la fabricació de membranes, catalitzadors tant per a la metanació del CO2 com per a la reacció de síntesi de Fischer-Tropsch, i diverses partícules inorgàniques nanomètriques per al seu ús en membranes de matriu mixta. Referent a la fabricació de les membranes, la tesi aborda principalment dos tipus: orgàniques i inorgàniques. Respecte a les membranes orgàniques, diferents materials polimèrics s'ha considerat com a candidats prometedors, tant per a la capa selectiva de la membrana, així com com a suport d'aquesta. S'ha treballat amb poliimides, ja que són materials amb temperatures de transició vítria molt alta, per al seu posterior ús en reaccions industrials que tenen lloc entre 250-300 °C. Per a aconseguir membranes molt permeables, mantenint una bona selectivitat, és necessari obtindre capes selectives de menys d'una micra. Emprant com a material de suport altre tipus de polímer, no és necessari estudiar la compatibilitat entre ells, sent menys complexa l'obtenció de capes fines. En canvi, si el suport és de tipus inorgànic, un exhaustiu estudi de la relació entre la concentració i la viscositat de la solució polimèrica és altament necessari. Diverses partícules inorgàniques nanomètriques es van estudiar per a afavorir la permeació d'aigua a través dels materials polimèrics. En segon lloc, quant a membranes inorgàniques, es va realitzar la funcionalització d'una membrana de pal¿ladi per a afavorir la permeació d'hidrogen i evitar la contaminació per monòxid de carboni. El motiu pel qual es va dopar amb un altre metall la capa selectiva de la membrana metàl¿lica va ser per a poder emprar-la en un reactor de Fischer-Tropsch. En relació amb el disseny i fabricació dels reactors, durant aquesta tesi, es va desenvolupar el prototip d'un microreactor per a la metanació de CO2, on una membrana polimèrica de capa fina selectiva a l'aigua es va integrar per a així evitar la desactivació del catalitzador i al seu torn desplaçar l'equilibri i augmentar la conversió de CO2. D'altra banda, un reactor de Fischer-Tropsch va ser redissenyat per a poder introduir una membrana metàl¿lica selectiva a l'hidrogen i poder injectar-lo de manera controlada. D'aquesta manera, i seguint estudis previs, el objectiu va ser millorar la selectivitat als productes desitjats mitjançant el hidrocraqueix i la hidroisomerització d'olefines i parafines amb l'ajuda de l'alta pressió parcial d'hidrogen. / [EN] The present thesis is focused on the development of new gas-separation membranes, as well as their in-situ integration on catalytic membrane reactors for process intensification. For this purpose, several materials have been synthesized such as polymers for membrane manufacture, catalysts for CO2 methanation and Fischer-Tropsch synthesis reaction, and inorganic materials in form of nanometer-sized particles for their use in mixed matrix membranes. Regarding membranes manufacture, this thesis deals mainly with two types: organic and inorganic. With regards to the organic membranes, different polymeric materials have been considered as promising candidates, both for the selective layer of the membrane, as well as a support thereof. Polyimides have been selected since they are materials with very high glass transition temperatures, in order to be used in industrial reactions which take place at temperatures around 250-300 ºC. To obtain highly permeable membranes, while maintaining a good selectivity, it is necessary to develop selective layers of less than one micron. Using another type of polymer as support material, it is not necessary to study the compatibility between membrane and support. On the other hand, if the support is inorganic, an exhaustive study of the relation between the concentration and the viscosity of the polymer solution is highly necessary. In addition, various inorganic particles were studied to favor the permeation of water through polymeric materials. Secondly, as regards to inorganic membranes, the functionalization of a palladium membrane to favor the permeation of hydrogen and avoid carbon monoxide contamination was carried out. The membrane selective layer was doped with another metal in order to be used in a Fischer-Tropsch reactor. Regarding the design and manufacture of the reactors used during this thesis, a prototype of a microreactor for CO2 methanation was carried out, where a thin-film polymer membrane selective to water was integrated to avoid the deactivation of the catalyst and to displace the equilibrium and increase the CO2 conversion. On the other hand, a Fischer-Tropsch reactor was redesigned to introduce a hydrogen-selective metal membrane and to be able to inject it in a controlled manner. In this way, and following previous studies, the aim is to enhance the selectivity to the target products by hydrocracking and hydroisomerization the olefins and paraffins assisted by the presence of an elevated partial pressure of hydrogen. / I would like to acknowledge the Spanish Government, for funding my research with the Severo Ochoa scholarship. / Escorihuela Roca, S. (2019). Novel gas-separation membranes for intensified catalytic reactors [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/121139 / TESIS