O crescimento dos países em desenvolvimento aumentará em várias vezes o consumo de energia, materiais e alimentos. Para suprir essa demanda é necessário o aproveitamento racional dos resíduos gerados por processos industriais, agrícolas e lixo urbano, transformando-os em energia economicamente competitiva com as outras formas de energia, e em materiais com propriedades otimizadas. O objetivo do presente trabalho foi comparar o comportamento da sílica da casca de arroz obtida por pré-hidrólise ácida seguida de calcinação controlada (Sil-PH) com sílicas de casca de arroz comerciais obtidas simplesmente pela queima da casca (Sil-B e Sil-C) e com a sílica comercial obtida da areia quartzítica (Sil-Z), como carga de reforço em borracha de estireno-butadieno (SBR), que é a mais usada na indústria de fabricação de pneus. Estudos foram conduzidos em SBR 1502, preparados conforme norma ASTM 3191-2010. Foram adicionadas à borracha as sílicas em concentrações de 0, 10, 20 e 40 ppcb. Foram conduzidos testes físicos, químicos, mecânicos, reométricos, dinâmico-mecânicos e análise térmica, bem como ensaios de inchamento dos corpos de prova em toluol e análise microestrutural das sílicas e dos compostos por microscopia eletrônica de varredura, com o objetivo de determinar a natureza do reforço. O número de ligações cruzadas foi avaliado e a energia de formação dessas ligações foi calculada. A relação entre as metodologias de cálculo da densidade de ligações cruzadas foi também avaliada, obtendo a caracterização desse tipo de carga de reforço não somente por correlações mecânicas mas também pela energia de formação das ligações. Os resultados mostraram que quanto maior a adição de sílica, maior é sua interação com a borracha. Dentre as sílicas adicionadas, Sil-Z alcançou os maiores valores de propriedades mecânicas dos compostos, e Sil-PH mostrou os melhores resultados dentre as sílicas de casca de arroz. Por avaliação por inchamento em toluol (teste estático) e por testes de tração e testes dinâmicos foi possível afirmar que as densidades de ligações cruzadas estão correlacionadas, Usando os resultados de reometria e as equações de Arrhenius estimou-se uma energia média de ligação, concluindo que esta corresponde a uma ligação do tipo covalente. Pelos valores de tan ? confirmou-se que os compostos com Sil-PH têm maior aderência no chão molhado do que aqueles com Sil-Z. A sílica nos compostos tende a diminuir a temperatura de transição vítrea. Os resultados da análise térmica mostraram elevada estabilidade térmica dos compostos com Sil-PH e Sil-Z. A falta de cominuição adequada da Sil-PH ocasionou uma dispersão irregular da sílica na SBR, uma molhabilidade parcial da sílica pela borracha e pelo agente de acoplamento, com consequente aparecimento de falhas na estrutura do composto. Por esse motivo as propriedades mecânicas dos compostos com Sil-PH foram inferiores às dos compostos com Sil-Z. / Developing countries are increasing by several times their consumption of energy, materials, and food. To attend their demand it is necessary to rationally reuse industrial, agricultural, and municipal solid waste residues, transforming them into economically competitive energy and materials with optimized properties. The objective of this work was to compare the behavior of a rice husk silica obtained by acidic prehydrolysis and controlled calcination (Sil-PH) with commercial amorphous silicas obtained from quartzite sand (Sil-Z) and from simply burned rice husks (Sil-B and Sil-C), as reinforcing filler in styrene-butadiene rubber (SBR) composites, which is the most used rubber in the tire manufacture industry. Studies were conducted on SBR 1502 rubber according to ASTM 3191-2010 in which amorphous silicas obtained from rice husk and quartzite silica were added at concentrations of 0, 10, 20, and 40 phr. Physical, chemical, mechanical, rheometric, dynamic-mechanical tests, thermal analysis, swelling studies in toluol and scanning electron microscopy of the silicas and composite specimens were made with objective to determine the nature of reinforcement. The number of crosslinks was evaluated and the energy of formation of these bonds calculated. The correlation between the methodologies of calculation of crosslink density was also evaluated, getting the characterization of this type of reinforcing filler not only by mechanical correlations but also by the energy of their formation. The results showed that the higher the content of added silica, the greater the interaction with rubber. According to the mechanical properties values Sil-Z achieved the highest properties values but Sil-PH showed better results compared to the other types of rice husk silicas. By evaluation by swelling in toluene (static), tensile tests and dynamic tests it was possible to affirm that the crosslink densities are correlated. By using the rheometry results and the Arrhenius equations the average bound was estimated to be of a covalent type. The silica in the compounds tends to lower the values of the glass transition temperature. The evaluation of tan ? showed that Sil-PH has more stickiness on the wet floor, which is an important property to tire application. Due to the lack of appropriate grinding of the Sil-PH the dispersion of the silica on SBR was irregular; partial wetting of the silica particles by rubber and silane had also occurred. Those facts had caused failures on the compound structural integrity, with a consequent lowering of the mechanical property values as compared to the compounds with Sil-Z addition.

Les glioblastomes sont des tumeurs cérébrales très agressives présentant une médiane de survie de 15 mois malgré l’usage du traitement de référence. Parmi les stratégies innovantes anti-glioblastome, les microARNs (miARN) constituent de nouvelles cibles et des outils thérapeutiques à fort potentiel. En outre, pour atteindre les cellules tumorales notamment au niveau loco-régional, les miARNs nécessitent d’être administrés grâce à des vecteurs sûrs et efficaces. L’objectif de ce travail a été de développer un système nanoparticulaire original de polyamidoamine réticulé (PAA) capable de véhiculer des miARNs au niveau cellulaire et tissulaire. Dans un premier temps, un test basé sur l’expression de la luciférase a été mis au point afin d’étudier la cytotoxicité et l’efficacité de nanoparticules des miARNs. Dans un second temps,des nanoparticules PAA-miARN ont été développées. Différentes conditions de formulation ont été testées afin d’optimiser la complexation entre miARNs et polymères. En l’absence d’efficacité cellulaire significative des premiers objets obtenus, des modifications du procédé de formulation ont été apportées, permettant une plus grande stabilité et une meilleure efficacité. Une fonctionnalisation par greffage de groupements biotine à des complexes PAA thio-réticulés a amélioré l’efficacité des internalisations. En conclusion, ce travail a permis le développement d’une méthode simple et rapide pour l’évaluation de l’efficacité et de la cytotoxicité de nanoparticules de miARN. La stabilité des nanoparticules a été augmentée par réticulation de thiolet leur internalisation a été améliorée par le greffage,adapté et modulable, d’un ligand cellulaire. / Glioblastoma are aggressive brain tumours with a median survival of 15 months even with the best currently available treatment options. microRNAs (miRNA) are ~23 nucleotide natural silencing RNAs that have great potentials to improve cancer treatment outcomes. Lack of a safe, stable and efficient delivery system has, however, hindered the use of miRNAs inclinical applications. The aim is therefore to develop amiRNA delivery system adapted to glioblastoma using linear chain cationic polyamidoamine (PAA) polymers.The first part involved the development of luciferase assay that combined the measurement of gene-knockdown efficiency and cytotoxicity of miRNA nanoparticles. The simple two-step procedure was more effective and sensitive compared to the conventional protein-based normalization method. The second part was focused on the development of miRNA nanoparticles. In the initial phase, conditions required for maximum miRNA-polymer binding was achieved, however, the newly developed miRNA-PAA nanoparticlesdid not produce significant functional gene-knockdown after cell treatment. The second stage was focused on the optimization of nanoparticle formulation as a function of stability in physiologicalionic concentration. Stable PAA-nanoparticles displaying moderate cellular uptake and gene-knockdown were obtained. The final stage of development was focused on PAA-nanoparticle tagging with biotin, which improved their cellular uptake. This work developed simple and informative luciferase assay ; the stability of miRNA-PAA-nanoparticles was improved by thiol-crosslinking and the functional performance was strongly enhanced by a simple butsmart method of ligand tagging.

Le stéarate de butyle, un matériau de changement de phase biosourcé (MCP), a été encapsulés dans des matrices polymères (pullulane, lignine, hémicelluloses) par la technique des émulsions concentrées. Les matrices polymères ont été réticulées avec du trimetaphosphate de sodium (STMP) dans des conditions alcalines afin d’obtenir un réseau poreux interconnecté rigide. L’influence du processus de séchage sur les matériaux composites obtenus a été étudiée, indiquant la lyophilisation comme la technique la plus efficace. Des études de calorimétrie à balayage différentiel (DSC) ont permis de déterminer que l’encapsulation de stéarate de butyle dans des matrices polymères ne modifiait pas ses propriétés thermiques de changement de phase. Des essais de compression mécanique et de résistance à la déformation ont permis d'évaluer le potentiel des monolithes en tant que panneaux de stockage de chaleur installés directement dans des bâtiments et des serres.Les produits de réticulation par le STMP ont été identifiés et caractérisés par RMN solide du31P. Il a ainsi été possible de synthétiser des monolithes ayant différents taux de réticulation afin d’optimiser la formulation d'encapsulation de MCP. Les matrices polymères vidée de tous leurs contenus liquides ont été étudiées par microscopie électronique à balayage afin d’étudier leur structure poreuse (distribution de taille des pores). Cette nouvelle approche d’encapsulation en une étape apparaît comme efficace et devrait permettre un développement important des applications énergétiques. / Emulsion-templated polymer based (pullulan, lining and hemicelluloses) monoliths encapsulating butyl stearate as bio-based phase change material (PCM) were synthesized. Polymer-bases were crosslinked with sodium trimetaphosphate (STMP) under alkaline aqueous conditions leading to an interconnected porous network. The influence of the drying process on the obtained composite materials morphology was studied indicating freeze-drying as the most effective technique. Differential Scanning Calorimetry (DSC) studies allow to assess that encapsulation of butyl stearate onto matrices do not alter its phase change thermal properties. Mechanical compression and strain resistance tests allowed to evaluate monoliths potential as heat storage panels installed directly in buildings and greenhouses, STMP crosslinking products were identified by solid-NMR characterization, this allowed to synthetize monoliths at different crosslinking yields to find a formulation that improves PCM encapsulation. Polymer matrices were studied by scanning electron microscopy to identify the pore size distribution obtained in STMP crosslinked materials. This new one-step encapsulating approach appears as efficient and cost-effective and is expected to find a broad development in energy storage applications

L’hydrosilylation d’alcènes est une réaction clé pour la synthèse d’huiles silicones fonctionnelles et d’élastomères silicones nécessite un catalyseur. Industriellement, le platine est utilisé or le coût important de ce métal motive la recherche de catalyseurs alternatifs plus compétitifs, notamment à base de métaux non précieux. Les travaux ont débuté sur des systèmes développés précédemment au laboratoire à base de cobalt et de nickel à haut degré d’oxydation et de ligands dicétones. Les cinétiques de réticulation ont été également suivies aussi bien par des mesures qualitatives d’arrêt d’agitation que par des mesures de rhéologie ou de chaleur de réaction par DSC. Ces catalyseurs sont actifs et robustes pour la réticulation. A la suite, des catalyseurs à base de cobalt portant en particulier des ligands amidures ont été étudiés. Associés à un ligand bidentate (P,N), les systèmes catalytiques sont compétitifs au platine de Karstedt pour l’hydrosilylation sélective d’alcènes. Ces catalyseurs réalisent également la réticulation d’huiles silicones à relativement basse température (20 min à 90°C). Un homologue au fer s’est également montré actif pour la réticulation d’huiles silicones démontrant la faisabilité d’une voie catalytique d’hydrosilylation à partir de complexes de fer non toxiques et robustes / Alkene hydrosilylation is a major tool for the synthesis of functionalized silicone oils and silicone elastomers and is catalyzed by transition metal complexes. Industrially, Platinum complexes are used. However, high and volatile cost and rarity of precious metals lead to the development of competitive alternative systems, especially catalysts based on non-precious transition metals. First, Nickel and Cobalt high-oxidation-state complexes bearing diketone ligands were studied. Those systems had been previously developed in the laboratory and the study has been completed. Crosslinking kinetics were followed by qualitative measures of “stop-stirring” time and by rheology and thermal analysis (DSC). Those catalysts are active over oxygen and stable for silicone-oil crosslinking. Then, Cobalt Catalysts bearing amido-based ligands were studied. When associated with a ligand (phosphino pyridine P,N), those systems are competitive with the Karstedt catalyst (Pt) for selective alkene hydrosilylation. They also allow for silicone-oil crosslinking at relatively low temperature (20 min at 90 °C). Finally, a homologous complex based on Iron was synthesized and showed activity for silicones’ crosslinking evidencing the feasibility of a catalytic hydrosilylation pathway from non-toxic and robust iron complexes.

Made available in DSpace on 2014-12-17T15:41:41Z (GMT). No. of bitstreams: 1 GuymmannCS.pdf: 1754712 bytes, checksum: 731ccc6c9bb4f783f3a118094959297b (MD5) Previous issue date: 2008-02-29 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / Latices based on acrylic acid and ethyl methacrylate, crosslinked with 1,6‐propoxylate‐hexanodiol diacrylate were synthesized via emulsion polymerization with different monomeric compositions. The resultant latices were thickened with different NaOH/(acrylic acid) molar ratios and were characterized by titrimetry, zeta potential measurements, turbidimetry, and capillary viscometry. Intrinsic viscosity was determined for an uncrosslinked copolymer, using toluene as solvent. All the latices were coagulated with NaCl and washed with water at 60?C analyzed by FTIR spectrophotometry, in order to characterize functional groups from the copolymer and crosslinking agent. / L?tices ? base de ?cido acr?lico e metacrilato de etila, reticulados com 1,6‐diacrilato de propoxilato hexanodiol, foram sintetizados via polimeriza??o em emuls?o, com diferentes composi??es monom?ricas. Os l?tices sintetizados foram espessados com diferentes raz?es molares NaOH/(?cido acr?lico) e caracterizados por titrimetria, medidas de potencial zeta, turbidimetria e viscometria capilar. Todos os l?tices foram coagulados com NaCl, lavados com ?gua destilada e em seguida secos a 60 0C, para a an?lise de FTIR. A viscosidade intr?nseca do l?tex n?o reticulado foi determinada utilizando tolueno como solvente. O potencial zeta foi usado para determinar a carga superficial das part?culas e o FTIR para caracterizar os grupos funcionais dos comon?meros.

La digestion enzymatique des protéines est une méthode de base pour les études protéomiques ainsi que pour le séquençage en mode « bottom-up ». Les enzymes sont ajoutées soit en solution (phase homogène), soit directement sur le gel polyacrylamide selon la méthode déjà utilisée pour l’isolation de la protéine. Les enzymes protéolytiques immobilisées, c’est-à-dire insolubles, offrent plusieurs avantages tels que la réutilisation de l’enzyme, un rapport élevé d’enzyme-sur-substrat, et une intégration facile avec les systèmes fluidiques. Dans cette étude, la chymotrypsine (CT) a été immobilisée par réticulation avec le glutaraldehyde (GA), ce qui crée des particules insolubles. L’efficacité d’immobilisation, déterminée par spectrophotométrie d’absorbance, était de 96% de la masse totale de la CT ajouté. Plusieurs différentes conditions d’immobilisation (i.e., réticulation) tels que la composition/pH du tampon et la masse de CT durant la réticulation ainsi que les différentes conditions d’entreposage tels que la température, durée et humidité pour les particules GA-CT ont été évaluées par comparaison des cartes peptidiques en électrophorèse capillaire (CE) des protéines standards digérées par les particules. Les particules de GA-CT ont été utilisés pour digérer la BSA comme exemple d’une protéine repliée large qui requit une dénaturation préalable à la digestion, et pour digérer la caséine marquée avec de l’isothiocyanate de fluorescéine (FITC) comme exemple d’un substrat dérivé afin de vérifier l’activité enzymatique du GA-CT dans la présence des groupements fluorescents liés au substrat. La cartographie peptidique des digestions par les particules GA-CT a été réalisée par CE avec la détection par absorbance ultraviolet (UV) ou fluorescence induite par laser. La caséine-FITC a été, en effet, digérée par GA-CT au même degré que par la CT libre (i.e., soluble). Un microréacteur enzymatique (IMER) a été fabriqué par immobilisation de la CT dans un capillaire de silice fondu du diamètre interne de 250 µm prétraité avec du 3-aminopropyltriéthoxysilane afin de fonctionnaliser la paroi interne avec les groupements amines. Le GA a été réagit avec les groupements amine puis la CT a été immobilisée par réticulation avec le GA. Les IMERs à base de GA-CT étaient préparé à l’aide d’un système CE automatisé puis utilisé pour digérer la BSA, la myoglobine, un peptide ayant 9 résidus et un dipeptide comme exemples des substrats ayant taille large, moyenne et petite, respectivement. La comparaison des cartes peptidiques des digestats obtenues par CE-UV ou CE-spectrométrie de masse nous permettent d’étudier les conditions d’immobilisation en fonction de la composition et le pH du tampon et le temps de réaction de la réticulation. Une étude par microscopie de fluorescence, un outil utilisé pour examiner l’étendue et les endroits d’immobilisation GA-CT dans l’IMER, ont montré que l’immobilisation a eu lieu majoritairement sur la paroi et que la réticulation ne s’est étendue pas si loin au centre du capillaire qu’anticipée. / Digesting proteins using proteolytic enzymes is a standard method in proteomic studies and bottom-up protein sequencing. Enzymes can be added in solution or gel phase depending on how the protein has been isolated. Immobilized, i.e., insoluble, proteolytic enzymes offer several advantages such as reusability of enzyme, high enzyme-to-substrate ratio, and integration with fluidic systems. In this study, we prepared glutaraldehyde-crosslinked chymotrypsin (GA-CT), which creates insoluble particles. The immobilization efficiency was determined by absorbance spectrophotometry and found to be 96% of the total amount of chymotrypsin added. Different immobilization (i.e., crosslinking) conditions such as buffer composition/pH and initial mass of CT during crosslinking as well as different storage conditions such as temperature, time and humidity for the GA-CT particles were evaluated by comparing capillary electrophoretic (CE) peptide maps of protein standards digested with the particles. The GA-CT particles were used to digest BSA as an example of a large folded protein that needs denaturation prior to digestion, and casein-fluorescein isothiocyanate (FITC) as an example of a small, labeled substrate to test enzyme activity in the presence of substrate-bound fluorescent groups. Peptide mapping of digests from GA-CT particles was achieved by CE with ultraviolet (UV) absorbance or laser induced fluorescence (LIF) detection. FITC-labeled casein was digested by GA-CT to the same extent as with free (i.e., soluble) CT. An immobilized enzyme microreactor (IMER) was fabricated by immobilizing CT inside a 250 µm i.d. fused-silica capillary tube pre-treated with 3-aminopropyltriethoxysilane to functionalize the inner walls with amine groups. Glutaraldehyde was reacted with the amine groups and then CT was immobilized by crosslinking to the GA. IMERs based on GA-CT were fabricated using an automated CE system and used to digest BSA, myoglobin, a 9-residue peptide and a dipeptide as examples of large, medium and small substrates. Digests were studied by comparing peptide maps obtained by CE coupled to either UV or mass spectrometric (MS) detection in order to evaluate immobilization conditions as a function of buffer composition/pH and reaction times. A separate study, which used fluorescence microscopy to investigate the extent and location of GA-CT immobilization in the IMER, showed that immobilization only takes place primarily near the capillary walls and that crosslinking does not extend as far into the center of the IMER as had been expected.

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Hidrogéis são materiais poliméricos com habilidade em intumescer em água e fluidos biológicos sem, contudo, se dissolver. Devido às suas propriedades de maciez e biocompatibilidade, estes materiais têm tido um crescimento enorme na área de engenharia de tecido, encapsulamento de células e liberação de drogas. Este trabalho visa a produção de hidrogéis de poli(N-vinil-2-pirrolidona) e seus copolímeros a partir de reticulações químicas. Como metodologia alternativa de produção de hidrogéis de poli(N-vinil-2-pirrolidona), foi estudada a reticulação do PVP por reação de Fenton, sendo que as concentrações dos reagentes foram avaliadas a fim de produzir um hidrogel com características semelhantes aos hidrogéis de PVP por radiação ionizante. O grande diferencial desta metodologia foi a rápida cinética de gelificação apresentada, creditanto um potencial de aplicação inédito. A partir de reticulações químicas mais brandas, foi estudada a produção de hidrogéis de copolímeros de N-vinil-2-pirrolidona e aldeídos com quitosana, e íons divalentes. Além de estudadas as propriedades relativas ao hidrogel tais como: conteúdo de gel, grau de intumescimento, cinética de reação, citotoxicidade, densidade de reticulação, massa molar média entre as ligações cruzadas e tamanho de poro. / Hydrogels are polymeric materials that have the ability to absorb water and biological fluids in their three-dimensional polymeric matrix without dissolution. Due to their interesting properties, such as softness and biocompatibility, there is a growing interest in their application in tissue engineering, cell encapsulation and drug delivery system. This work aims at the study of hydrogels from poly(N-vinyl-2-pyrrolidone) and copolymers produced by chemical crosslinking methods. PVP crosslinking by Fenton reaction was studied as an alternative methodology to produce poly(N-vinyl-2-pyrrolidone) hydrogels. The reagents concentrations were evaluated, in order to produce a hydrogel with the same properties of the hydrogels prepared by high energy radiation. The advantage of this methodology is its fast jellification kinetic, warranting new potential unprecedented applications. From mild chemical crosslinking methods, the production of hydrogels from copolymers of N-vinyl-2-pyrrolidone and aldehydes with chitosan, and divalent ions was studied. Hydrogels properties as: gel content, swelling ratio, reaction kinetics, cytotoxicity, crosslinking density, molecular weight and pore size were investigated.

Ces travaux de thèse portent sur l’élaboration et l’étude des propriétés thermomécaniques de polymères dynamiques incorporant des dérivés borés. Tout en appliquant ce concept sur une variété d’architectures macromoléculaires : copolymères fonctionnels, briques di- et tri-fonctionelles, deux réactivités distinctes du bore ont été étudiées et exploitées. Une large gamme de méthodes de caractérisation a été utilisée pour mener à bien ce projet : spectroscopies FTIR et RMN sous différents stimuli, ainsi que de nombreuses analyses thermiques et mécaniques. Dans un premier temps, nous avons considéré la formation de paires de Lewis frustrées entre des acides de Lewis (organoboranes) et des bases de Lewis (amines et phosphines) stériquement encombrés, cette interaction pouvant être fortement modulée par la participation d’un troisième composé tels que des molécules de gaz. Ainsi, nous avons été capables de former des réseaux dynamiques réticulables de façon réversible avec le dioxyde de carbone. Dans un second temps, nous avons mis en évidence une nouvelle réactivité dans les esters boroniques cycliques impliquant une ouverture de cycle à haute température, assistée par la présence de nucléophiles. Cette réaction a été mise à profit pour former des polymères réticulés dynamiquement, pouvant atteindre des températures de transition vitreuse jusqu’à 220°C et dé-réticulables par dilution avec un bon solvant du polymère (apolaire). Cette réactivité a été appliquée à une variété de polymères accessibles par copolymérisation radicalaire (styrène, éthylène, acétate de vinyle, acrylate de butyle) ou par post-fonctionnalisation de polymères commerciaux (polybutadiène) / This thesis focuses on the development and study of thermomechanical properties of dynamic polymers incorporating borylated derivatives. While applying this concept to a variety of macromolecular architectures: functional copolymers, di- and tri-functional bricks, two distinct reactivities of boron have been explored. A wide range of characterization methods has been used to carry out this project: FTIR and NMR spectroscopies under numerous stimuli, as well as many thermal and mechanical analyses. In a first step, we considered the formation of Frustrated Lewis Pairs between Lewis acids (organoboranes) and Lewis bases (amines and phosphines) sterically hindered, as this interaction can be strongly modulated by the participation of a third compound such as gas molecules. Thus, we have been able to form dynamic networks reversibly crosslinkable with carbon dioxide. In a second step, we demonstrated a new reactivity in cyclic boronic esters involving a ring-opening at high temperature, assisted by the presence of nucleophiles. This reaction has been used to form dynamically crosslinked polymers, which can reach glass transition temperatures up to 220°C and de-crosslinkable by dilution in a good (apolar) polymer solvent. This reactivity has been applied to a variety of polymers accessible by radical copolymerization (styrene, ethylene, vinyl acetate, butyl acrylate) or by post-functionalization of commercial polymers (polybutadiene)

Membrane-based acid gas (e.g., CO2) separation, gas dehydration and humidification, as well as solvent dehydration are important to the energy and process industries. Fixed carrier facilitated transport membranes can enhance the permeation without compromising the selectivity. The development of suitable fixed carrier membranes for CO2 and water permeation, and understanding of the transport mechanism were the main objectives of this thesis. Poly(N,N-dimethylaminoethyl methacrylate) (PDMAEMA) composite membranes were developed using microporous polysulfone (PSF) or polyacrylonitrile (PAN) substrates. The PDMAEMA layer was crosslinked with p-xylylene dichloride via quaternization reaction. Fourier transform infrared, scanning electron microscopy, adsorption tests, and contact angle measurements were conducted to analyze the chemical and morphological structure of the membrane. It was shown that the polymer could be formed into thin dense layer on the substrates, while the quaternary and tertiary amino groups in the side chains of PDMAEMA offered a high polarity and hydrophilicity. The solid-liquid interfacial crosslinking of PDMAEMA led to an asymmetric crosslinked network structure, which helped minimize the resistance of the membrane to the mass transport. The interfacially formed membranes were applied to CO2/N2 separation, dehydration of CH4, gas humidification and ethylene glycol dehydration. The membranes showed good permselectivity to CO2 and water. For example, a CO2 permeance of 85 GPU and a CO2/N2 ideal separation factor of 50 were obtained with a PDMAEMA/PSF membrane at 23oC and 0.41 MPa of CO2 feed pressure. At 25oC, the permeance of water vapor through a PDMAEMA/PAN membrane was 5350 GPU and the water vapor/methane selectivity was 4735 when methane was completely saturated with water vapor. On the other hand, the relative humidity of outlet gas was up to 100 % when the membrane was used as a hydrator at 45oC and at a carrier gas flow rate of 1000 sccm. For used for dehydration of ethylene glycol at 30oC, the PDMAEMA/PSF membrane showed a permeation flux of ~1 mol/(m2.h) and a permeate concentration of 99.7 mol% water at 1 mol% water in feed. This work shows that the quaternary and tertiary amino groups can be used as carriers for CO2 transport through the membrane based on the weak acid-base interaction. In the presence of water, water molecules in the membrane tend to form a water "path" or water "bridge" which also help contribute to the mass transport though the membrane. In addition, CO2 molecules can be hydrated to HCO3-, which reaction can be catalyzed by the amino groups, the hydrated CO2 molecules can transport through the water path as well as the amino groups in the membrane. On the other hand, for processes involving water (either vapor or liquid) permeation, the amino groups in the membrane are also helpful because of the hydrogen bonding effects.