This dissertation includes two parts: Part I “natural fiber/thermoplastic composites” and Part II “studies of organo-clay synthesis and clay intercalation by epoxy resins”. The use of light weight renewable natural materials instead of heavy mineral-based materials is important to generate lighter materials for sustainable human development. Renewable natural fibers have already been used to reinforce thermosetting and thermoplastic polymer composites. The abundance of hydroxyl groups in natural fibers causes two problems: (1) high water moisture uptake and (2) incompatibility with hydrophobic polymer matrices. Surface modifications have been used to solve these problems. In part I of this dissertation, the modifications of wood fiber/flour by acid chlorides and maleated polypropylene were studied. High density polyethylene (HDPE)/wood flour (WF) composites were investigated in Chapter 1 of Part I. Polypropylene (PP)/WF composites were studied in Chapter 2 of Part I. In Chapter 3 of Part I, kenaf/PP composites were explored. Finally, the effect of carbon nanofibers (CNF) and composite blending processes were studied in Chapter 4 of Part I. Composite flexural properties and water absorption properties were evaluated. Flexural strengths and flexural moduli were obtained by four-point bending tests. Micromorphologies were investigated by scanning electron microscope (SEM). Part II presents studies of organo-clay syntheses and the mechanism of clay intercalation by epoxy resins. Ammonium and imidazolium pillaring agents were synthesized and then used to modify clay. A pillaring agent with epoxy functional groups was also synthesized. Clay intercalation by epoxy resins was affected by the epoxy resin polymerization rate, viscosity and temperature. The diffusion rate of monomers and polymers into and out of clay galleries is a function of temperature and a major factor in intercalation. The clay’s degree of nano dispersion in epoxy composites were investigated by TEM. The clay thermostabilites were studied by TGA.

Controlling the layout of elasticity in materials provides new opportunities for generating various functionalities such as shape-morphing capability, large stretchability, and elastic softening for aeronautics, drug delivery, soft robotics, and stretchable electronics applications. Recently, techniques building upon kirigami principles, the Japanese art of paper cutting, have been considered an effective strategy to control stiffness and deformation of materials by systemically integrating cut patterns into inextensible sheets. The performance of kirigami-inspired materials relies primarily on geometric features defined by cut patterns rather than chemistry of constituents, which can enable high compatibility with diverse material sets across a wide range of length scales. However, kirigami has been relatively unexplored to control adhesion and current challenges such as the intrinsic trade-off between high deformability and load-bearing capacity limits applications that require large shape change and structural strength. This thesis demonstrates that the kirigami approach is a powerful tool to control interfacial properties of adhesive films, and that composite approaches in kirigami-inspired material can overcome the deformation-strength trade-off. The kirigami principle is applied to adhesives to control adhesion through arrays of linear cut patterns (Chapter 2). The spatial layout of elasticity in the kirigami-inspired adhesive enhances adhesion over homogeneous adhesive systems and generates anisotropic adhesion. The utility of the proposed adhesive design criteria is further extended to complex non-linear cut patterns (Chapter 3). These non-linear patterns significantly enhance adhesion relative to linear patterns in adhesives and unpatterned films, while also enabling easy release and spatial control of adhesion across a sheet. The enhancement enabled by cut geometry remains effective in diverse adhesives, on various surfaces, and in wet and dry conditions. The adhesion dependence on cut geometry is further investigated to understand how arrays of sub-patterns adjacent to primary non-linear patterns affect adhesion performance (Chapter 4). Kirigami composites are also developed to overcome the trade-off between large deformability and load-bearing capacity (Chapter 5). A composite architecture is developed consisting of low melting point metal alloys incorporated into patterned elastomeric layers. This composite approach shows the ability to rapidly morph into complex, load-bearing shapes, while achieving reversibility and self-healing capability through phase change driven by embedded heaters. The utility of the multi-functional composite is demonstrated through a multimodal morphing drone which transforms from a ground to air vehicle and an underwater morphing machine which can be reversibly deployed to collect cargo. This thesis is then summarized by discussing key findings, contributions, and future perspectives (Chapter 6). / Doctor of Philosophy / Controlling stiffness across a material sheet provides new opportunities for emerging fields such as soft robotics and stretchable electronics. Recently, a technique based on kirigami principles, the Japanese art of paper cutting, has gained interest as an effective strategy for designing materials. This kirigami technique provides intriguing possibilities to create tunable and highly functional materials by adding cuts (e.g. controlling material geometry) without changing chemistry. This kirigami technique is also compatible with diverse materials from extremely small (e.g. nanoscale) to large scales (e.g. over millimeters to even beyond). However, engineered kirigami has been mostly used for creating deformable electronics and stretchable films. Further, although it makes the material soft and stretchable, it can reduce load-bearing capacity and strength. In this thesis, kirigami is utilized to engineer adhesives with unique properties and create multi-functional morphing materials that overcome extensibility-loading-bearing trade-offs. Inspired by the kirigami concept, an array of linear cut patterns is integrated into an adhesive strip, and adhesion is measured (Chapter 2). The kirigami adhesive shows stronger adhesion over an unpatterned adhesive, and it also shows high adhesion in one direction but low adhesion in the other direction. The utility of the adhesive design criteria is then extended to complex non-linear cut patterns (Chapter 3). This enables enhanced adhesion, easy release, spatial control of adhesion, and rapidly customized adhesive properties through a digital fabrication approach. The adhesion is strongly controlled by the cut size and density, thus this kirigami technique is applicable to diverse adhesives, on various surfaces, and in wet and dry conditions. The effects of non-linear patterns on adhesion are studied in further detail (Chapter 4). Diverse arrays of sub-patterns around original non-linear patterns are demonstrated to control the adhesion performance. Following the adhesion work in previous chapters, shape-changing materials are studied. Here, a kirigami approach is used to develop multi-functional, morphing composites (Chapter 5). The composite shows the ability to change into complex shapes while support loads through hard metal alloys and kirigami-inspired soft encapsulating layers, while achieving reversibility and self-healing capability through the phase change between solid and liquid states by an embedded heater. The utility of the multi-functional composite is demonstrated through a morphing drone which transforms from a ground to air vehicle and an underwater morphing machine which can be reversibly deployed to collect cargo. This thesis is then summarized by discussing key findings, contributions, and future perspectives (Chapter 6).

No / Autodesk Moldflow Simulation Insights has been used to predict the fibre orientation within notched specimen injection mouldings. Currently available fibre orientation models including the classis Folgar-Tucker (FT), the modified version of Folgar-Tucker (MFT) and the Reduced Strain Closure (RSC) [1] have been assessed, alongside the relative effects of their associated parameters, for their suitability for fibre orientation prediction. Compared to experimentally determined values the Reduced Strain Closure model was shown to most closely represent the fibre orientation within the moulded components.

The American way of life is becoming increasingly transient in nature. But at the same time there is also the inherent need to have a sense of rootedness, the need for a place to call home, to belong. The current thesis is an architectural exploration of creating a dialogue between this duality. The approach is to explore a composite system, where modular prefabricated architecture is implemented in conjunction with traditional building practices. The idea is to address the transient nature and sense of belonging by combining the prefabricated modular approach with the site-built traditional approach. This study proposes that there are two types of spaces in a house that creates the overall spatial experience of a home. These can be termed as core functional spaces and more fluid or flexible spaces. Core functional spaces are bedroom, kitchen, bathroom, dining, formal living etc. Flexible spaces are more fluid in terms of function, for example – family living, lobby, lounge, connecting/common spaces etc. In the current thesis, core functional units are proposed to be developed as modular units. The reason is, because of their defined functionality they can be designed as basic modules. The modules would be prefabricated in a factory and transported to site. The modules themselves are composed of panelised systems. This allows for a flexibility in different permutation of layouts and enables adaptability of the house with changing family dynamics and other functional needs, thus addressing the transient nature of life. The fluid spaces are proposed to be built on site allowing greater flexibility in terms of dimensions, construction material and design. This type of space addresses the sense of permanence and rootedness as they are designed to be responsive to the site forces and define the unique characteristics of a home based on client’s unique requirements. Overall, the composite approach addresses transience and changing family demographics through the modular, prefabricated, core functional units. Prefabrication is adopted for saving time and expenses of construction. Assembly line techniques, grouping of similar tasks and use of skilled labour help in achieving that. The core functional spaces serve some basic purposes which is common for every house in general. So these spaces can be considered as repeating units and forms, and can be considered for prefabrication. For example, Kitchens, bathrooms or bedrooms can be treated as basic units and thus can be designed as prefab modules. Prefabricated, modular construction is rapidly gaining interest in the building construction industry. Implementation of modular construction improves the efficiency in production and safety in the working environment. This reduces the necessity to transport many skilled workers to the construction site. Prefabrication also helps avoid other adverse conditions like exposure to harsh weather or a hazardous environment, lack of water or power etc. On the other hand, the proposed composite approach addresses permanence through the site-built components. These components are responsive to different sites and different client needs. The fluid spaces are the spaces that do not serve any specific or basic purpose for the designed architectural piece to function as a home, but rather work as a space that binds all the core functions together. The fluid spaces ne the architectural experience of a house and how the core functions are coming together to form an architectural piece that one can call home. For example, common lobby spaces, informal living, corridors etc work as fluid spaces where all the functional spaces are connected. For different households, different family needs, the fluid space can receive the functional modules differently thereby defining the architectural space differently. This type of spaces can be designed using traditional on-site construction which provides the language of permanence and rootedness. Proposed modular units themselves follow a panelised construction, so it is easy to add or remove panels to support the different arrangements of modules around different types of site built elements. Thus the composite system supports the transience by providing adaptability and permanence by responding and being rooted to the site. The overall spatial experience created by the juxtaposition of these two systems and two types of textures is the focus of this thesis. / Master of Architecture / Modern life is increasingly becoming fast and mobile. The idea of building one permanent accommodation for life that does not adapt to changes in family dynamics is increasingly going away. On the contrary, there is an inherent need in human beings to feel rooted to the place they live in. The current thesis aims to address this duality from an architectural perspective. The thesis proposes an architectural system that combines age-old, traditional architectural style with novel construction concepts. In traditional systems, houses were built from scratch, on-site. Which made them rooted to the place and directly influenced by the site. But new, prefabrication concepts propose constructing parts of a house as modules off-site, in a factory, and transporting them to the site. This off-site, module-based process makes a house easily adaptable to changes with changing family dynamics. This thesis proposes that there are two types of spaces in a house that creates the overall spatial experience of a home. These can be termed as core-functional spaces and flexible spaces. Core functional spaces are bedroom, kitchen, bathroom, dining, formal living etc. Flexible spaces are more fluid in terms of functionality, for example – family living, lobby, lounge, connecting/common spaces etc. In the current thesis, core functional units are proposed to be developed as modular, factory-built units. The reason is, because of their distinct functionality, they can be designed as modules. The modules would be prefabricated in a factory and transported to site. This approach enables adaptability of the house with changing family dynamics, thus addressing the transient nature of life. The flexible spaces are proposed to be built on site. This type of space addresses the sense of permanence and rootedness as they are designed to be responsive to the site forces and define the unique characteristics of a home based on client’s unique requirements. The architectural implementation presented here celebrates the coming together of these two types of building processes. Overall, the composite approach addresses transience and changing family demographics through the modular, prefabricated, core functional units. On the other hand, the proposed composite approach addresses permanence through the site-built components. The composite system supports the transience by providing adaptability and permanence by responding and being rooted to the site. The overall spatial experience created by the juxtaposition of these two systems and two types of textures is the focus of this thesis.

An increasing need for smaller, higher-power-density devices is driving the development of more advanced topologies for use in power architectures. The challenge, however, is to reduce the size of the passive components in circuit boards (e.g., the inductors), which are typically the most bulky. There are two ways to approach this problem. The first is to redesign the flux in the inductor in order to minimize its size; the second is to optimize the magnetic properties of the constituent magnetic materials, which include permeability, density, resistivity, core loss density, saturation magnetization value, fluidity, sintering temperature, and others. Compared to altering the nature of solid magnetic materials to reduce space constraints, modifying the magnetic composite is preferred. The most popular candidates for use in magnetic composites are magnetic powders and polymer composites. In particular, when metal alloys are chosen as magnetic powders they have high initial permeability, high saturation magnetization values, but low electrical resistivity. Since polymers can serve as insulation materials, mixing metal alloys with polymers will increase electrical resistivity. The most common metal alloy used is nickel-iron (permalloy) and Metglas. Since existing modeling methods are limited in (a) that multiphasic composites cannot be utilized and (b) the volume fraction of magnetic particles must be low, this investigation was designed to utilize FE (finite element) simulation to analyze how magnetic properties change with the distribution of permalloy powder or Metglas flakes in composites. The primary magnetic properties of interest in this study are permeability and core loss density. Furthermore two kinds of magnetic composites were utilized in this investigation: a benzocyclobutene (BCB) matrix-permalloy and a benzocyclobutene (BCB) matrix-permalloy-based amorphous alloy (Metglas 2705M) material. In our FE simulations, a BCB matrix-permalloy composite was utilized in a body-centered cubic model with half-diameter smaller particles serving as padding. The composite was placed in a uniform magnetic field surrounded by a material whose relative permeability was equal to zero in simulation. In comparison to experimental results, our model was able to predict permeability of composites with volume fraction higher than 52%. It must be noted, however, that although our model was able to predict permeability with only 10% off, it was less effective with respect to core loss density findings. The FE model also showed that permeability will increase with an increasing volume fraction of magnetic particles in the composite. To modify the properties of the composite material, the model of the BCB matrix-permalloy-Metglas composite followed model simulations up to the point at which flakes were inserted in BCB matrix-permalloy composite. The thickness of flakes was found to be an important factor in influencing resulting magnetic properties. Specifically, when the thickness of flakes decreased to quarter size at the same volume fraction, the permeability increased by 15%, while core loss density decreased to a quarter of the original value. The analysis described herein of the important relationship between magnetic properties and the composites is expected to aid in the development and design of new magnetic composite materials. / Master of Science / Power converters are essential for a wide variety of electronic applications (e.g., mobile phones, motor drives, etc.). And with the current push toward miniaturization, power converters that are smaller in size and feature higher power density are demanded. The most challenging aspect of reducing overall size while maintaining or, preferably, increasing the power density of a power converter is to reduce the size of the passive components in the circuit boards (e.g., the inductors). To optimize the performance of an inductor, the magnetic properties of the constituent magnetic materials in an inductor must be well designed. In particular, scientists and engineers are focusing on the two most important characteristics of a magnetic material—namely its permeability and core loss density. In order to achieve the objective of high relative permeability and low core loss density, the incorporation of magnetic powders and polymer composites into the fabrication of magnetic materials is being considered. Since this method tends to require a great deal of trial and error to determine optimal fabrication parameters, it can be both time consuming and costly. This study, therefore, was designed to simplify the fabrication process by investigating the effects of altering the parameters of a number of constituent components in a series of composites. Specifically, this investigation targeted the impact of altering the volume percentage, the shape, and the species of each component on the properties of composite materials by simulation, which was useful in predicting the performance of the magnetic materials under scrutiny. The simulation method utilized herein was FE (finite element), which was effective in determining the permeability and core loss density of the magnetic properties of interest in this study.

L’objectif de ces travaux de thèse est de contribuer à la compréhension d’un procédé de mise en forme composite appelé EPITHER. Il s’agit d’un procédé visant la réalisation de pièces composites massives à utilisations structurelles pour les marchés de l’automobile et de l’aéronautique. Il a été breveté en 2011 et en 2015/2016.Les trois étapes de réalisation des pièces EPITHER sont les suivantes : enroulement d’une préforme en optimisant l’anisotropie du composite en fonction des chemins d’efforts de la pièce réelle, mise en forme de la préforme par thermoformage, apport de propriétés morphologiques supplémentairesLes travaux de thèse s’orientent autour de trois axes majeurs : la mise en place d’une phase expérimentale, la compréhension des étapes de consolidation des pièces et l’influence des paramètres de mise en forme. / The objective of this work is to contribute to the comprehension of a new composite forming process which name is EPITHER. This forming process was created to produce massive composites parts used for structural applications in automotive and aeronautics industries. Two patents have been deposed in 2011 and in 2015/2016.There are three steps in the forming process EPITHER: winding a preform in order to maximize and optimize the anisotropy of the composite considering the mechanical specifications of the final part, forming the preform by a thermoforming step, add morphological properties in a last step.The Phd deals with three major research axis: setting up an experimental study, the comprehension of the consolidation steps and a study of the consolidation parameters.

O desenvolvimento da sociedade humana somente atingiu o estágio atual devido à utilização de materiais compósitos de diferentes misturas, que vem desempenhando um papel fundamental no desenvolvimento da sociedade moderna. Com a finalidade de explorar o crescente interesse nas pesquisas de novos materiais, este trabalho apresenta um estudo sobre as propriedades do compósito elastomérico a base de poli(éter-siloxano) e sólido particulado cerâmico de titanato de bário (3 BaTiO). Amostras com quantidades adequadas dos componentes, matriz polimérica não curada e particulada de titanato de bário, foram curadas em diferentes concentrações (puro, 10, 20, 30, 40 e 50 %) por meio de mistura em massa em uma câmara glove box em ambiente de nitrogênio, até obtenção de mistura homogênea. O copolímero puro e uma série de compósitos com diferentes concentrações foram submetidos a ensaios de inchamento, análises térmicas gravimétricas, calorimetria diferencial exploratória, caracterização morfológica por microscopia eletrônica de varredura, ensaios mecânicos de tração e medidas elétricas. Por meio dessa série de técnicas de caracterização foram observadas propriedades bem distintas entre o polímero puro e os compósitos, caracterizado pelo aumento das ligações cruzadas. Neste trabalho foi também construído um capacitor de placas paralelas para teste de capacitância elétrica dos materiais preparados, visando o estudo do comportamento elétrico dos materiais em estudo. / The present development of the human society should be credited to the use of the composite and blend materials. In this dissertation composites of an elastomer, poly(ether-siloxane), along with barium titanate are prepared and their properties are studied. Nanoparticles of barium titanate were incorporated in the elastomer in the range 0-50 wt% through bulk mixing under nitrogen atmosphere in a glovebox, using a porcelain mortar and pestle. The mixtures thus prepared were placed in molds and allowed to cure in order to prepare specimens for properties analyses. The composites were submitted to swelling tests, thermal gravimetric analysis (TGA), differential scanning calorimetry (DSC), mechanical strength tension test, electrical measurements and electron scanning microscopy (SEM). It was possible to make a correlation between the observed properties and the morphology and composition of the composites. Additionally, a parallel plates capacitor for injection and test of small samples was built and used to evaluate the electrical capacitance of the composites prepared in this work.

Les besoins technologiques toujours grandissants dans la société moderne suscitent la nécessité de développer des matériaux multifonctionnels innovants. Ceci est vrai surtout dans des domaines de pointe, tels que la microélectronique et la conversion d'énergie, où on demande aux matériaux de limiter la dissipation de chaleur tout en ayant de bonnes propriétés électroniques.L'optimisation d'un tel type de matériaux est toutefois complexe: une forte réduction de la conductivité thermique se fait en général aux dépenses de la conductivité électrique. Une stratégie qui a été récemment introduite est de développer des matériaux hétérogènes à l'échelle nanométrique, dits « nanocomposites ». Malgré le potentiel dont ils ont déjà fait preuve, à ce jour la compréhension fondamentale de leurs propriétés reste encore limitée. Dans cette thèse nous présentons une étude fondamentale des propriétés de transport dans des composites basés sur une matrice amorphe contenant des inclusions cristallines de tailles nanométriques, afin d'acquérir une compréhension microscopique des mécanismes en jeu. Pour ce faire, nous avons effectué une étude expérimentale dans deux composites intermétalliques, un verre métallique et un verre chalcogénure, obtenus par cristallisation directe du verre. Nous avons pu mettre en évidence un comportement fortement dépendant du contraste de propriétés entre la matrice vitreuse et les inclusions cristallines. Nos conclusions ont trouvé confirmation dans des simulations numériques par dynamique moléculaire que nous avons effectué' sur des systèmes modèles, qui ont en effet permis de mettre en évidence l'effet d'un contraste de rigidité sur les propriétés vibrationnelles de ce type de composite / Face to the growing technological needs in the modern society, the need has arisen of developing novel multifunctional materials, able to simultaneously assure different functions.This is especially important in advanced technologies, such as microelectronics and energy harvesting, where heat dissipation reduction is essential, while keeping good electrical properties.Optimizing such materials represents however a challenging task: lowering thermal conductivity generally implies lowering the electrical conductivity as well. A new strategy has recently aroused consisting in exploiting heterogeneous materials at the nanoscale, so-called “nanocomposites”. Despite their great potential, the fundamental understanding of their properties is still lacking.In this thesis, we present a fundamental investigation of the transport properties in composites made of nano-inclusions embedded in an amorphous matrix, aimed to get a microscopic insight into the mechanisms ruling transport in such materials.To this purpose, we have carried on an experimental study in two intermetallic composites, based on a metallic glass and a chalcogenide glass, where crystalline inclusions were directly obtained from the glass temperature-induced recrystallization.We find that transport behavior is strongly dependent on the properties’ contrast between the amorphous matrix and the crystalline inclusions.Our findings are comforted by our theoretical results, obtained by molecular dynamics simulations on a model composite system, which highlight the effect of the rigidity contrast on the vibrational properties of such material, and thus on thermal transport

Dans de nombreux domaines, tels que l’aéronautique et l’aérospatial, les matériaux composites sont utilisés par soucis d’allègement des structures. Pour cette même raison, les assemblages mettant en jeu ces matériaux sont préférentiellement réalisés par collage. Ce mode d’assemblage présente aussi l’avantage d’éviter tout risque d’endommagement engendré par des ruptures de fibres. Néanmoins, chacune des opérations de mise en œuvre du collage doit être maîtrisée, en particulier lorsque des élastomères réticulés, réputés peu aptes au collage, sont impliqués. Ainsi, un primaire est généralement utilisé pour assurer l’adhésion entre l’élastomère et le matériau composite. Dans ce travail de thèse, il s’agit de supprimer l'étape d’enduction du primaire à la surface de l’élastomère réticulé avant bobinage des fibres imprégnées de résine. Cette suppression vise à réduire les risques Hygiène Sécurité Environnement (primaire classé Cancérigène, Mutagène et Reprotoxique) et permet de simplifier les cycles de fabrication. Pour assurer l’adhésion entre l’élastomère réticulé à base d’EPDM et le matériau composite à matrice époxyde sans élément intermédiaire, il est essentiel de comprendre les mécanismes de formation de l’assemblage : création de liaisons physiques, influence de la rugosité de surface, diffusion de monomères et réactions chimiques. Cette compréhension permet par la suite de modifier la formulation des matériaux, dans notre cas remplacer le copolymère présent dans l’élastomère, afin d’améliorer l’adhésion et de s’affranchir de tout traitement de surface. / In many fields, in particular in aeronautic and aerospace, assemblies by bonding instead of bolting are used in order to lighten structures involving composite materials. Furthermore chemical bonding minimizes the risk of damage by fibers breaking. In this context, our research work concerns the assembly between a cured elastomer, known to be difficult to be bonded, and a composite material without using adhesives which are classified as carcinogenic, mutagenic and toxic agent. In order to have a good adhesion between cured EPDM elastomer and composite material with epoxy resin without adhesive, it is crucial to understand mechanisms of self assembly of these materials: role of physical bonds, influence of roughness, monomers diffusion and chemical reactions. This good understanding allows us editing material formulations, in our case copolymer in elastomer, to improve adhesion and remove surface treatment.

Ce travail s’inscrit dans le cadre du conditionnement de liquides organiques radioactifs sans filière de gestion. Le procédé est basé sur une émulsification de liquide organique dans un silicate alcalin permettant la synthèse d’une matrice géopolymère. La première partie de ce travail consiste à effectuer un criblage sur différents liquides organiques. Un système modèle représentatif des différentes huiles et une formulation de référence de géopolymère sont définis. La seconde partie porte sur la structuration des enrobés de liquide organique, du mélange des réactifs jusqu’à l’obtention du matériau final, et vise à déterminer les phénomènes permettant la synthèse d’un composite homogène. Les deux dernières parties visent à caractériser le matériau en étudiant respectivement sa structure (structure chimique, porosité du géopolymère et dispersion de l’huile) et ses propriétés vis-à-vis de l’application à l’immobilisation de déchets radioactifs. Contrairement aux matrices cimentaires silico-calciques, la structuration du géopolymère n’est pas impactée par la nature chimique des liquides organiques. Seules les huiles acides inhibent ou freinent la réaction de géopolymérisation. Afin d’obtenir un matériau homogène la présence de molécules tensio-actives est obligatoire. Le mécanisme de stabilisation des émulsions, à la base du procédé, repose sur une synergie entre les molécules tensio-actives et les particules d’aluminosilicates présentes dans la pâte de géopolymère. Les cinétiques (chimique et mécanique) de la géopolymérisation ne sont pas impactées par la présence d’huile ou de tensio-actifs. Seule une augmentation des modules viscoélastiques et du caractère élastique des pâtes peut être constaté. Cette différence de comportement rhéologique est en majeure partie liée à la présence de tensio-actif. La structure de la matrice est identique à celle d’un géopolymère pur de même formulation. Le liquide organique est dispersé dans des inclusions sphériques dont le rayon est compris entre 5 et 15 μm. Ces gouttelettes sont séparées les unes des autres, et de l’environnement par le réseau mésoporal du géopolymère. Les propriétés mécaniques et de lixiviation ont aussi été évaluées. / This work is included in the management of radioactive organic liquids research field. The process is based on an emulsification of organic liquid in an alkali silicate solution allowing the synthesis of a geopolymer matrix. The first part of this work consists in carrying out a screening on different organic liquids. A model system representative of the various oils and a geopolymer reference formulation are then defined. The second part deals with the structuration of the organic liquid/geopolymer structuration, from the mixture of the reactants to the final material. It aims at determining the phenomena allowing the synthesis of a homogeneous composite. The last two parts aim at characterizing the composite by studying its structure (chemical structure, porosity of the geopolymer and dispersion of the oil) and its properties with respect to the application to the immobilization of radioactive waste. Unlike calcium silicate-based cementitious matrices, the structure of the geopolymer is not affected by the chemical nature of the organic liquids. Only acid oils inhibit or slow down the geopolymerization reaction. In order to obtain a homogeneous material, the presence of surfactant molecules is necessary. The emulsion stabilization mechanism at the base of the process is relying on a synergy between the surfactant molecules and the aluminosilicate particles present in the geopolymer paste. The kinetics (chemical and mechanical) of the geopolymerization are not impacted by the presence of oil or surfactants. Only an increase in the viscoelastic moduli and the elastic character of the pastes can be observed. This difference in rheological behavior is mainly due to the presence of surfactant. The structure of the matrix is identical to that of a pure geopolymer of the same formulation. The organic liquid is dispersed in spherical inclusions whose radius is between 5 and 15 μm. These droplets are separated from each other, and from the environment by the mesoporous network of the geopolymer. Mechanical and leaching properties were also evaluated.