Ces travaux de recherche s’inscrivent dans le cadre du développement de nouvelles surfaces biocompatibles capables de contrôler l’adhésion d’agents pathogènes responsables de maladies neurodégénératives telles que les maladies de Creutzfeld Jacob, Alzheimer, Parkinson et Lewis. Deux axes de recherche ont été privilégiés. Notre approche se focalise en amont des dosages sur l’amélioration des procédures de stockage des prélèvements biologiques réalisés dans des tubes de type Eppendorf. Ces tubes en polypropylène induisent une perte du matériel génétique de plus de 70% accentuant la faible concentration en agent pathogène pour la détection immunoenzymatique. Dans le but de réduire les phénomènes indésirables d’adhésion des agents pathogènes à la surface des supports de stockage, deux voies de traitement ont été envisagées dans ce travail de thèse. La première consiste à modifier la surface du tube Eppendorf en une étape par décharge plasma fluoré, la seconde à créer de nouvelles surfaces hydrophiles en deux étapes couplant la technique des plasmas froids au greffage de polymères, les agents pathogènes pouvant être hydrophiles ou hydrophobes. Avec cette dernière technique, une voie originale a été abordée de part l’utilisation de solutions de greffage complexes composées à la fois de polymères et de molécules tensioactives. Les surfaces ainsi obtenues présentent une nano-structuration. Toutes les étapes de modification de la surface interne des tubes de stockage ont été caractérisées. Ces surfaces sont alors décrites selon leur caractère hydrophile ou hydrophobe grâce à la détermination des énergies de surface polaire et apolaire, selon leur charge de surface obtenue par mesure du potentiel d’écoulement, selon leur composition chimique déterminée par spectroscopie à photoélectrons X (XPS) et enfin selon leur topographie et leur rugosité relevées par microscopie à force atomique (AFM). Les interactions entre les groupements fonctionnels ainsi obtenus à la surface des tubes de stockage après les divers traitements et les protéines antigéniques considérées ont été interprétées en se référant aux différents modèles de l’adhésion pour des gammes de pH proches des protocoles biologiques usuels. Afin de s’assurer que ces nouvelles surfaces permettent bien une diminution de l’adhésion des agents infectieux sur la paroi interne des tubes de polypropylène, des analyses immunoenzymatiques ont été réalisées au sein des centres hospitaliers participant au projet STREP NEUROSCREEN n° LSHB-CT 2006-03 7719 (CRPP de Liège et CHU de Lyon). Ces analyses ont permis de montrer que la modification des surfaces entraîne une diminution de l’absorption des agents pathogènes jusqu'à 100% permettant ainsi une meilleure détection. / The research work presented in this thesis considers the development of newµbiocompatible surfaces that are able to control the adhesion of specific proteins responsible for the development of neurodegenerative diseases such as Creutzfeldt–Jakob, Alzheimer, Parkinson and Lewis body disease. Our approach was focused on problems prior to the detection step, which were never considered before, particularly on the improvement of Eppendorf tubes that are used for the storage of body fluids like cerebrospinal fluid and blood. Namely these tubes made of polypropylene induce the depletion of biological material, in some cases even over 70%, resulting in a low concentration of these proteins for the further immunoenzymatic detection. With the purpose to reduce the adhesion of specific proteins on the surface of supports, two courses of treatments were anticipated. The first one consists of surface modification by highly reactive fluorine plasma treatment and the second one incorporates development of new hydrophilic surfaces by coupling two techniques, plasma activation and subsequent grafting of polymer materials. With the latter approach, an original way of surface modification has been attained by using complex solutions of polymers and surfactants that permits controlled configuration of nanostructured surfaces. All steps of surface modifications were well characterized by different physicochemical methods. The surface hydrophilic/hydrophobic character was determined by measurements of polar and apolar surface energy, surface charge by magnitude of zeta potential, surface chemistry was evaluated by x-ray photoelectron spectroscopy (XPS), while the surface roughness and topography were monitored by atomic force microscopy (AFM). The interactions between functional groups of treated supports and proteins were interpreted referring to different models of adhesion established for a range of pH values close to the classical biological protocols. Finally, in order to validate that the new surfaces are able to prevent or decrease the adhesion of neurodegenerative agents on the surfaces of Eppendorf tubes, the immunoenzymatic analyses were carried out in hospital centres of partners that were participating to the project STREP NEUROSREEN n° LSHB-CT-2006-03 7719 (Centre de Recherche sur les Protéines Prion; Liege (ULG), Hospices Civils de Lyon (CHUL) and Lancaster University (L-UNI)). These analyses showed that the treatments led to a decrease of antigen adsorption up to 100%, enabling (allowing) better detection of pathogenic agents.

Dix molécules organiques modèles simulant les fonctions chimiques des superplastifiants utilisés dans la formulation des bétons ont été intercalées dans les hydrates cimentiers lamellaires conduisant à la formation de phases AFm hybrides. Les interfaces entre les deux sous-réseaux organiques et inorganiques de ces composés hybrides ont été étudiées afin de caractériser les interactions entre hydrates cimentiers et adjuvants organiques lors de la prise du béton. Les affinités de ces molécules vis-à-vis du feuillet minéral ont pu être comparées et il en ressort les deux séries suivantes : -PO32- > -SO3- > -CO2- pour les parties hydrophiles et C7-R > Φ-R > C5-R > C2-R pour les parties hydrophobes. L’interface organique-inorganique i.e. le mode d’accrochage et l’orientation de la molécule organique au sein de l’espace interlamellaire ont principalement été caractérisés par DRX sur poudre et spectroscopie infrarouge. Différents modes de connexion ont pu être identifiés par intercalation et par greffage. Les molécules organiques examinées sont ainsi orientées soit perpendiculairement, soit parallèlement aux feuillets associés à différents mode d’accroche. Différents taux d’hydratation de ces hydrants hybrides ont ensuite été identifiés et un travail de résolution structurale sur la phase insérant l’anion C6H5SO3- a permis de préciser l’organisation structurale de l’espace interlamellaire. Finalement, une étude sur l’intercalation de quelques superplastifiants commerciaux a mis en évidence un phénomène d’exfoliation de ces hydrates lamellaires. L’étude préalablement réalisée sur des molécules modèles permet alors de mieux comprendre les interactions se produisant au sein du milieu complexe que constitue un béton frais. / Ten organic molecules models simulating the chemical functions of superplasticizers used in concretes formulation were intercalated into lamellar cement hydrates to synthesize hybrid AFm phases. The interfaces between the organic and inorganic networks of these hybrid compounds have been studied to characterize the interactions between cementitious hydrates and organic additives in concrete. The affinities of these molecules toward the mineral layers have been compared and display the following tendencies : -PO32- > -SO3- > -CO2- for the hydrophilic parts and C7-R > Φ-R > C5-R > C2-R for the hydrophobic parts. The organic-inorganic interface (connection mode and orientation of the organic molecule) of the hybrid AFm phases was characterized by powder WRD and infrared spectroscopy. Organic molecules are oriented either perpendicular or parallel to the sheets resulting from different connection modes mainly intercalation and also grafting. The various hydration levels of these hybrids hydrates were then determined, and a structural resolution was attempted on AFm inserting C6H5SO3- anion allowing a description of its interlayer structure. Finally, a study on the intercalation of some commercial superplasticizers highlighted the exfoliation phenomenon for these lamellar hydrates.The present study on model molecules leads to a better understanding of the interactions occuring in complex fresh concrete environment.

The objective of this work was to evaluate the fundamentals of the currently available CO2 separation technologies and provide a solution for the efficient capture of carbon dioxide from various point source emitting industries. In order to realize a robust approach to advancing the solution to this global issue, the versatility of the process to the range of compounds contained within the stream(s) to be processed must be maintained. It is clear that adsorption, membrane, and aqueous amine based processes are all capable. However, only aqueous amine scrubbing appears economically viable at the current stage of development. In order to challenge this, and potentially drive the separation costs lower, this work centered on hybridizing aqueous amine chemistry and dry adsorption based separations to produce a novel nano-porous material capable of efficient removal of CO2 from flue gas (5% CO2 balance N2 with moisture). In order to combine aqueous amine scrubbing with dry adsorption, a few approaches were considered and evaluated. These included, amine impregnation within the vast pore volume of PE-MCM-41, surface grafting of various amino silane compounds, and finally, a novel approach of volume based amine functionalization (3D grafting). Application of pore-expanded MCM-41 (PE-MCM-41) mesoporous silica coated with 3-[2-(2-aminoethyl-amino)ethylamino]propyltrimethoxysilane (TRI) has been extensively examined for the adsorption of CO2 from N2. A systematic study of the amine loading as a function of the relative amounts of TRI and water used during the grafting procedure, and the temperature of the grafting reaction was carried out. Extremely high levels of active amine content were achieved using prehydrated silica surfaces at grafting temperatures below reflux in order to facilitate thermally controlled water-aided surface polymerization of the aminosilanes. Abstract iii The CO2 adsorption capacities and rates were determined for all materials as a function of the amount of TRI and water per gram of support added to the grafting mixture. The optimal TRI grafted PE-MCM-41 adsorbent exhibited a 2.65 mmol/g adsorption capacity at 25 °C and 1.0 atm for a dry 5% CO2 in N2 feed mixture, which exceeded all literature reported values, for both meso- and microporous materials under the conditions used in this study. Further, the apparent adsorption and desorption rates with the amine functionalized materials were exceedingly high. When considering the grafted amine quantity, the adsorption capacity and rate were found to be mutually dependent on each other, exhibiting an apparent optimal combination. In comparison to zeolite 13X, the optimally loaded TRI-PE-MCM-41 was far superior in terms of dynamic adsorption and desorption performance. These results were further enhanced when the adsorbents were challenged with a humid stream of 5% CO2/N2. The TRIPE-MCM-41 exhibited a 10% increase in CO2 adsorption capacity, whereas the 13X zeolite did not retain any significant CO2 adsorption capacity. The novel concept of an internally variably staged permeator was introduced. A theoretical model was developed and used as the basis for simulation studies. The advantage of the internal variably staged design was shown to permit a very high extent of separation similar to a two stage permeator for purity, while maintaining similar flux rates as per a single stage permeator. This IVSP concept has also taken existing membrane materials and mechanically translated their process performance to a higher level. As such, the unit should prove effective for front end process stream cleanup requirements prior to an adsorption process with the novel TRI-PE-MCM-41 nano-porous adsorbent.

Les maladies ostéoarticulaires représentent environ 10% de l'ensemble des pathologies identifiées en France chaque année. Pour l'instant aucun traitement permettant la réparation du tissu cartilagineux n'est vraiment disponible hormis la pose d'un implant articulaire. Mais, malgré de nombreux efforts pour développer de nouveaux matériaux pour les implants articulaires leur durée de vie in vivo s'avère souvent très décevante par rapport aux extrapolations faites à partir de simulations ex-vivo. Les discordances entre les durées de vie in vivo et ex vivo sont principalement imputées aux conditions d'essais ex vivo insuffisamment réalistes vis-à-vis des propriétés physico-chimiques des lubrifiants biologiques. Dans ce contexte, ce travail vise à agir sur la réactivité physicochimique des surfaces frottantes des implants articulaires en UHMWPE afin de maîtriser l'accrochage des molécules lubrifiantes de type phospholipidique (MPC) et ainsi d'augmenter leurs performances tribologiques. Les résultats montre que l'activation physicochimique des surfaces de UHMWPE par des couches de MPC peuvent diminuer l'usure des surfaces polymères d'implant mais cela nécessite un contrôle de la qualité de la couche MPC greffée (densité surfacique, épaisseur, accrochage chimique, adsorption physico-chimique) afin de garantir une bonne tenue mécanique et tribologique. D'autre part les résultats montrent que la présence de lubrifiant biologique (substitut du fluide synovial à base de liposomes) peut réduire l'usure des surfaces de UHWPE même si la couche de MPC est peu dense et peu épaisse / The osteoarticular diseases account for approximately 10% of all identified pathologies in France each year. Currently there is really no effective treatment available for repairing of the cartilage tissue except for the installation of articular implants. However, in spite of many efforts to develop new materials for articular implants, their lives in-vivo is often disappointing compared with the extrapolations from ex-vivo simulations. The discordances between the lives in-vivo and ex-vivo are mainly contributed to the experimental conditions of ex-vivo insufficiently realistic related to the physic-chemical properties of biological lubricants. In this context, this work aims to investigate physicochemical reactivity of friction surface of UHMWPE articular implants to control the attachment to the lubricating molecules of phospholipid types (MPC) and increase their tribological performance. The results showed that the physicochemical activation of UHMWPE surface with layers of MPC can reduce the surface wear of polymer implant but it requires some quality controls of the grafted MPC layer (surface density, thickness, chemical bonding, physical and chemical adsorption) to ensure good mechanical and tribological performance. In addition, the result also showed that the presence of organic lubricant (substitute synovial fluid containing liposomes) can reduce the surface wear of UHMPE even if the layer is sparse and thin

Orientador: Jose Ricardo de Albergaria-Barbosa / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-01T00:32:36Z (GMT). No. of bitstreams: 1 Rabelo_LuisRaimundoSerra_D.pdf: 7546603 bytes, checksum: ab098403b9103521ab84bb486ab82543 (MD5) Previous issue date: 2001 / Resumo: O objetivo deste trabalho foi realizar um estudo comparativo de diferentes materiais preenchimentos ósseos sobre o processo de regeneração óssea guiada em defeitos perimplantares do tipo fenestração, realizados em fêmur de coelhos. Defeitos circulares de 2,6mm de diâmetro foram confeccionados na face medial do fêmur, de forma a expor a superfície do implante. Foram colocados 40 implantes de titânio de 6mm de comprimento por 2,6mm de diâmetro, bilateralmente, em fêmur de coelhos. Os defeitos foram preenchidos, de acordo com o grupo estudado, com: vidro bioativo, matriz óssea liofilizada de origem humana, osso autógeno e preenchimento por coágulo, que serviu como controle do experimento. Todos os defeitos, após preenchimento, foram protegidos por membrana de celulose. Os animais foram sacrificados após períodos de 3 e 6 semanas, quando blocos ósseos contendo os implantes, foram descalcificados e processados para posterior análise histológica em microscopia óptica comum e análise histométrica. Os dados histométricos revelaram melhores resultados de formação óssea no período de 3 semanas para os grupos Osso autógeno e Osso liofilizado (37,8% e 37,1%, respectivamente), e não apresentaram diferenças estatísticas significantes entre si. No período de 6 semanas o grupo Osso autógeno apresentou os maiores resultados de formação óssea (64,1%) / Abstract: The purpose of this study was compare the bone healing after different bone grafting materiais in bone tissue regeneration around implants in rabbit' s femur. Forty 6 x 2.6mm titanium implants were placed, bilaterally, in the femur of twenty New Zealand rabbits. Circular defects (2.6mm in diameter) were created at mesial of each femur, in order to expose implant threads. Defects were filled with human demineralized freeze-dried bone (Dembone), rabbit bone-chips autografts (autogenous bone) , bioactive glass granules (Perioglas) and control group filled with blood clot (control). Ali defects were protected with cellulose membranes. Rabitts were sacrificed 3 and 6 weeks after graft placement, the specimens were cut into block sections on a low speed bur and submited to histologic and histometric analysis. Among the graft materiais, autogenous bone and human demineralized freeze-dried bone provided the greatest amount of bone formation (37,8% and 37,1%, respectively) after 3 weeks of healing, with no statistically signifcant difference between them. After 6 weeks, autogenous bone provided the densest and greatest amount bone formation (64,1 %). Between 3 and 6 weeks, the greatest amount of bone formation was provided by autogenous bone grafts, and the control group showed a lesser quantity of bone formation as compared to the grafted groups / Doutorado / Cirurgia / Doutor em Clínica Odontológica

Diploma thesis deals with the grafting of vinyltrimethoxysilane (VTMOS) onto poly(3–hydroxybutyrate)PHB. Subsequent characterization of the amount of grafted VTMOS and changes in the thermal properties associated with the rate of crystallization. The theoretical part deals with mechanism and the influences of grafting. In the experimental part VTMOS was grafted onto PHB without subjecting VTMOS to hydrolysis and subsequent crosslinking. By differential scanning calorimetry (DSC) and Avrami equation, the effect of grafted silane group on pure was studied. The MVR was used to compare the rheological properties of initial PHB, grafted PHB and crosslinked PHB by siloxane linkages.

This Master’s thesis deals with the problematics of radically initiated compounding of polyethylene by 1-vinyladamantane. Theoretical part focuses on the theory of grafting processes and how they are influenced by chosen process parameters, as well as the properties of used monomer. In experimental part, two sets of experiments were designed, in both cases the chemicals used were polyethylene LITEN MB 87, (2,5-dimethyl-2,5-bis(tert-butylperoxy) hexane), also called Trigonox 101, as the initiator, and chemicals called Ionol and Irgafos 168 as stabilizers. The experiments were carried out in a Brabender batch mixer, the temperature was 180 – 185 °C, the reaction time was 5 minutes. The analytic methods used to evaluate the prepared samples’ properties were the tensile testing, the Charpy notch test, measuring of the melt flow index, analyzing the torque during kneading and the analysis of infrared spectra of the samples. By carrying out of these experiments it was found that excessive crosslinking was present with mass fraction of initiator being as low as 2 %. It was also concluded that under these conditions the modification does not improve tensile properties of the material, but it does improve the impact strength, albeit slightly. The influence of the modification on flow properties needs to be investigated further. A presence of vinyl groups was observed in infrared spectra, suggesting the presence of ungrafted vinyladamantane.

Diplomová práce se zabývá roubováním maleinanhydridu a anhydridu kyseliny itakonové na kyselinu poly(mléčnou) (PLA). U modifikované kyseliny poly(mléčné) byla sledována závislost konverze monomerů na různých molárních poměrech monomer/iniciátor při teplotách 180°C a 200°C. Množství naroubovaného monomeru bylo stanovováno acidobazickou titrací a pomocí FT-IR spektroskopií. Vliv stupně naroubování na krystalinitu modifikované PLA byl zjišťován pomocí diferenční kompenzační kalorimetrie, DSC. Degradace PLA byla orientačně pozorována pomocí indexu toku taveniny, MFI.

The theoretical part describes the principles of the free-radical induced grafting and the influence of various parameters on the reactions course. The literature research summarizes the latest knowledge in the field of the reactive modification of polypropylene (PP), it is mainly focused on the PP modification using an unsaturated acid anhydrides. Theoretical part describes the various procedures and modification of technology in order to increase the grafting yield of maleation. The experimental part is determined by the influence of the stabilizers concentration, the peroxide structure, and the binary mixture of monomers on the grafting yield and the reaction course. In the first part, the critical stabilizers concentration was determined based on the experimentally obtained relationship between the grafting yield and the stabilizers concentration. A kinetic schema of grafting of MAH onto PP in the presence of stabilizers has been proposed and compared with the experimental results. The effect of the stabilizers on the extent of the undesirable b-scission was evaluated based on the melt flow rate (MFR) and the rheological curves of PP-g-MAH. In the second part, the effect of the peroxide structure and the concentration of reactants on the grafting yield of PP modification with MAH and itaconic anhydride (IAH) was observed. The initial grafting yield Rg has been experimentally determined and compared with a defined area of theoretical values of Rg. The extent of b-scission was significantly influenced by the structure and the concentration of peroxide, as shown by the results of MFR and the rheological curves of PP-g-MAH. The last part of the doctoral thesis is focused on the assessment of the combination of MAH and IAH as comonomers on the grafting yield. At first, the reference polymers were prepared using the solution polymerization of MAH, and IAH, and copolymerization of MAH with IAH. The reference polymers were analyzed by FTIR, DSC, WAXS to confirm the probable copolymerization of MAH and IAH. The dependence of the reaction enthalpy on the reaction time was observed using simulations of bulk polymerization of MAH, IAH and mixtures MAH and IAH "in situ" in isothermal calorimeter. PP was subsequently modified with a combination of MAH and IAH as comonomers in order to assess its effect on the grafting yield

L’électrochimie devient incontournable dans les nouvelles technologies de stockage et de conversion de l’énergie. La réaction de dégagement de dihydrogène constitue aujourd’hui une réaction à fort intérêt sociétal qui est au cœur des nouvelles technologies permettant l’élaboration de systèmes pour la conversion de l’énergie. Cependant, des problématiques liées à l’utilisation de certains métaux nobles (le platine notamment) en tant que catalyseurs restent encore à résoudre. Ce travail de thèse s’inscrit dans les thématiques scientifiques de l’équipe de Recherche et d’Innovation en Electrochimie pour l’Energie (ERIEE) qui s’intéresse depuis plusieurs années à la substitution de ces métaux nobles par l’utilisation de catalyseurs moléculaires constitués de composés organiques contenant des métaux de transition comme centre électro-actif pour application dans les électrolyseurs industriels. Ce travail de thèse se focalise sur l’étude d’une famille de complexes moléculaires à base de métaux de transition (Co ou Fe), les clathrochélates, caractérisés par différentes structures chimiques. Le choix des ligands de ces complexes ainsi que l’étude des processus de fonctionnalisation sur des substrats ad hoc, sont des éléments déterminants dans l’appréhension des performances électro-catalytiques obtenues.Ces électro-catalyseurs ont été étudiés à la fois en solution (phase homogène) et fonctionnalisés à la surface d’électrodes solides. Leurs propriétés physico-chimiques ainsi que leurs performances électro-catalytiques vis-à-vis de la réaction de dégagement d’hydrogène, ont été caractérisés de façon systématique.La microscopie électrochimique à balayage (SECM) a notamment permis d'effectuer une caractérisation à l’échelle locale des propriétés électro-catalytiques des électrodes modifiées. / Electrochemistry is becoming a major field in new energy storage and conversion technologies. Nowadays, the hydrogen evolution reaction (HER) is a reaction of great societal interest, which is at the heart of new technologies enabling the development of systems for the conversion of energy. However, some issues related to the use of noble metals (platinum, in particular) as catalysts have not been solved yet. This thesis is part of the scientific approach of the Research and Innovation in Electrochemistry for Energy (ERIEE) research group which has been interested for several years in the substitution of these noble metals by the use of transition metal based electro-catalysts. These molecules consist of organic compounds containing transition metals as an electro-active center for application in industrial electrolysers. This thesis focuses on the study of a family of molecular complexes based on transition metals (Co or Fe), the so-called clathrochelates, characterized by different chemical structures. The choice of the ligands constituting these complexes as well as the study of their functionalization processes on ad hoc substrates, constitute key elements in the apprehension of the resulting electro-catalytic performances.These electro-catalysts were studied both in solution (homogeneous phase) and functionalized at the surface of solid electrodes. Their physico-chemical properties as well as their electrocatalytic turnover for the hydrogen evolution reaction, have been systematically characterized.In particular, scanning electrochemical microscopy (SECM) allowed for the characterization of the electrocatalytic properties of modified electrodes at the local scale.