Currently, there is very little research available on nonpoint source pollution from rural watersheds. Government regulatory agencies are desperate for information regarding the causes of nonpoint source pollution, which includes the relationship between suspended soil particles and dispersion. Since soil dispersion is dependent on clay mineralogy, knowing the clay mineralogy of the soil in an area can help predict sediment loads entering the surrounding surface waters. This information is necessary to protect the resource value of our rivers, lakes, and estuaries, as well as to protect recreational activities such as fishing or hunting; but most importantly, this information is necessary to ensure the safety of our drinking water supply. Clay mineralogy and its influence on dispersion, as well as dispersion and its relation to water quality are the focus of this study. Soil mineralogy affects water quality in several ways: soil mineralogy determines the dispersivity of the clay portion of the soil and dispersive clays are likely to end up as suspended sediment in surface waters; weathering reactions contribute elements to water as dissolved load, and the sorption properties of clay minerals contribute to soils' ability to filter and carry pollutants. Through the use of X-ray diffraction, dispersivity, atomic absorption spectrometry, cation exchange capacity, and petrographic microscopy, this study shows that the clay mineral fraction of a soil determines the dispersivity, and that dispersed clay minerals contribute excess nutrients and metals as nonpoint source pollutants to surface waters.

Suite à la perturbation thermique induite par le stockage de déchets radioactifs, les modifications structurales risquant d'affecter les constituants minéraux réactifs (smectite) de la barrière argileuse concernent principalement la quantité et la localisation de la charge foliaire et modifient potentiellement les propriétés d'hydratation de ces minéraux. Une méthodologie a donc été développée afin de décrire, par simulation des diffractogrammes de rayons X (raies 00ℓ), ces propriétés d'hydratation et en particulier l'hétérogénéité résultant de l'interstratification de feuillets présentant différents états d'hydratation. L'étude des propriétés d'hydratation d'une montmorillonite (charge octaédrique) bassecharge a montré que l'affinité du cation interfoliaire pour l'eau gouverne l'état d'hydratation et l'épaisseur des feuillets hydratés. L'augmentation de la quantité de charge induit, en désorption d'eau, un décalage vers les plus basses humidités relatives des transitions entre les différents états d'hydratation. D'autre part, les beidellites étudiées (charge tétraédrique) présentent des états d'hydratation plus hétérogènes que les montmorillonites. L'approche développée a également permis de décrire les modifications structurales induites par une perturbation chimique (influence du fond chloré, pH). Enfin, nous avons pu mettre en évidence le lien structural entre l'épaisseur des feuillets élémentaires et la quantité d'eau interfoliaire, pour laquelle un nouveau modèle structural, permettant de mieux décrire leur distribution de position, a été établi pour les feuillets bi-hydratés.

La série argileuse du Callovo-Oxfordien recouvre une transition minéralogique entre un interstratifié illite/smectite désordonné (R0 - partie supérieure) et un autre ordonné (R1 - partie inférieure. Or, la minéralogie de ces argiles conditionne les propriétés de rétention de la formation ainsi que leur réactivité en réponse à une perturbation physico-chimique potentiellement induite par le stockage. Dans une optique de caractérisation fine des minéraux argileux du Callovo-Oxfordien, les méthodes conventionnelles et simplificatrices d'identification comme l'utilisation d'abaques issus de la littérature ont été invalidées. La méthode retenue consiste à comparer directement des diffractogrammes de rayons X calculés avec ceux enregistrés sur un même échantillon après différents traitements et à en reproduire toutes les caractéristiques (positions des pics, rapports d'intensité, profils) à l'aide d'un modèle structural unique. Les minéraux argileux du forage EST104 peuvent ainsi être décrits comme un mélange de trois phases principales : une illite, une smectite et un interstratifié illite/expansible désordonné (R0) de composition fixe (35% exp.). Avec la profondeur les caractéristiques structurales de ces phases sont constantes. La transition minéralogique précédemment décrite traduit la modification des proportions relatives des différentes phases. Cette description diffère de celle classiquement proposée pour l'illitisation diagénétique des séries sédimentaires. Cependant, l'utilisation des mêmes outils sur une série diagénétique de référence conduit à une description similaire. Ces résultats novateurs impliquent de reconsidérer les mécanismes réactionnels proposés pour ces minéraux ainsi que leur modélisation cinétique. Enfin, la réactivité des minéraux argileux du Callovo-Oxfordien en réponse à une perturbation alcaline est très limitée par la présence de matière organique qui recouvre les particules argileuses et protège ainsi les sites réactifs des minéraux argileux.

O Brasil é produtor de argilas e conta com grandes reservas deste recurso natural. Porém, grande parte da sua produção é comercializada seca e moída. O desenvolvimento de argilas para seu uso como reforço em nanocompósitos poliméricos constitui uma opção para os produtores desta matéria prima que teriam assim um produto com maior valor agregado. Este trabalho visa avaliar o potencial uso como nanocarga de duas argilas nacionais provenientes da Bacia de Taubaté, São Paulo, denominadas ALIGRA e SANTA FÉ. As frações de tamanho de partícula médio menor de 0,02 mm, obtidas por peneiramento á úmido da argila homogeneizada e seca, foram utilizadas no desenvolvimento do trabalho experimental. Os estudos de caracterização, envolvendo análise granulométrica, química, mineralógica, morfológica, térmica e textural, revelaram características muito semelhantes em ambas às argilas. Fração argila, maior de 70% em massa. Composição química conforme a definição química de uma argila e os teores de seus componentes mostram valores intermédios entre as apresentadas pelas bentonitas e argila caulinítica usadas com fins de comparação. Ressaltamse boas propriedades adsorventes. Área superficial específica BET ao redor de 120 m2/g, valor maior do que o apresentado por muitas bentonitas naturais (74,5 m2/g). Predominantemente mesoporosas, com poros, maiormente em forma de fenda, característicos da estrutura em camadas das argilas. Baixa capacidade de troca catiônica, 12 meq/100g. Difratogramas de raios-X revelaram a predominância do estratificado ilita/esmectita, caulinita e quartzo na argila ALIGRA, e de ilita, caulinita e quartzo na argila SANTA FÉ. Prosseguiu-se com a argila ALIGRA a preparação da argila organofílica. A argila organofílica foi obtida por troca catiônica com o sal quaternário de amônio: cloro cetril trimetil amônio, depois de homogeneizada em sódio com cloreto de sódio. Análises FTIR e TGA indicaram que houve inserção dos cátions orgânicos. Testes preliminares foram feitas, preparando misturas das argilas com matriz de polipropileno e usando como agente compatibilizante polipropileno enxertado com anidrido maleico. Resultados de ensaios de tração reportam algumas melhoras nas propriedades testadas com as composições preparadas com as argilas purificadas. Com as composições com argilas organofílicas somente foi melhorado o alongamento na rotura. Estudos ais aprofundados são recomendados. / Brazil is a producer of clay and has large reserves of this natural resource. However, most of its production is sold dried and milled." The development of clays for use as reinforcement in polymer nanocomposites is an option for these raw material producers, who would thus have a product with higher added value. This study aims to evaluate the potential use as nanofiller of two national clays from Taubaté basin, São Paulo, called ALIGRA and SANTA FE. In this experiment, the fractions of particles with average size of less than 0.02 obtained through wet sieving were used. The characterization studies involving granulometric, chemical, mineralogical, morphological, thermal and textural analysis, revealed very similar characteristics in both the clays. Clay fraction (< 2&#956;m) is higher 70%. Chemical composition as the definition of clay and its components show intermediate values between those present by bentonite and kaolinitic clays used here for purposes of comparison. It should be underlined good adsorptive properties. Specific surface area BET (aBET) around of 120 m2/g, this value is higher than showed by many bentonites (74.5 m2/g). They are predominantly mesoporous, the pores predominantly in slit-shape in accordance to the characteristic layered structure of the clays. Low cationic exchange capacities (CEC), 12 meq/100 g. XRD results for samples saturated with ethylene glycol and heated revealed the predominance of illite/smectite, kaolinite and quartz in ALIGRA clay, and illite, kaolinite and quartz in the clay SANTA FE. Work continued with the clay ALIGRA the preparation of organoclay. The organoclay was obtained by ion exchange with the quaternary ammonium salt: cetril trimethyl ammonium chloride, after homogenized in sodium with sodium chloride. FTIR and TGA analyzes indicated that there was integration of organic cations Preliminary tests were performed by preparing mixtures of clays with a polypropylene matrix, and using polypropylene grafted with maleic anhydride as a compatibilizer. Results of tensile tests made in the polypropilene- purified clay compositions have reported some improvements in some tested properties. With polipropilene-organofilized compositions only improved elongation on break. More detailed studies are which would be required.

O Brasil é produtor de argilas e conta com grandes reservas deste recurso natural. Porém, grande parte da sua produção é comercializada seca e moída. O desenvolvimento de argilas para seu uso como reforço em nanocompósitos poliméricos constitui uma opção para os produtores desta matéria prima que teriam assim um produto com maior valor agregado. Este trabalho visa avaliar o potencial uso como nanocarga de duas argilas nacionais provenientes da Bacia de Taubaté, São Paulo, denominadas ALIGRA e SANTA FÉ. As frações de tamanho de partícula médio menor de 0,02 mm, obtidas por peneiramento á úmido da argila homogeneizada e seca, foram utilizadas no desenvolvimento do trabalho experimental. Os estudos de caracterização, envolvendo análise granulométrica, química, mineralógica, morfológica, térmica e textural, revelaram características muito semelhantes em ambas às argilas. Fração argila, maior de 70% em massa. Composição química conforme a definição química de uma argila e os teores de seus componentes mostram valores intermédios entre as apresentadas pelas bentonitas e argila caulinítica usadas com fins de comparação. Ressaltamse boas propriedades adsorventes. Área superficial específica BET ao redor de 120 m2/g, valor maior do que o apresentado por muitas bentonitas naturais (74,5 m2/g). Predominantemente mesoporosas, com poros, maiormente em forma de fenda, característicos da estrutura em camadas das argilas. Baixa capacidade de troca catiônica, 12 meq/100g. Difratogramas de raios-X revelaram a predominância do estratificado ilita/esmectita, caulinita e quartzo na argila ALIGRA, e de ilita, caulinita e quartzo na argila SANTA FÉ. Prosseguiu-se com a argila ALIGRA a preparação da argila organofílica. A argila organofílica foi obtida por troca catiônica com o sal quaternário de amônio: cloro cetril trimetil amônio, depois de homogeneizada em sódio com cloreto de sódio. Análises FTIR e TGA indicaram que houve inserção dos cátions orgânicos. Testes preliminares foram feitas, preparando misturas das argilas com matriz de polipropileno e usando como agente compatibilizante polipropileno enxertado com anidrido maleico. Resultados de ensaios de tração reportam algumas melhoras nas propriedades testadas com as composições preparadas com as argilas purificadas. Com as composições com argilas organofílicas somente foi melhorado o alongamento na rotura. Estudos ais aprofundados são recomendados. / Brazil is a producer of clay and has large reserves of this natural resource. However, most of its production is sold dried and milled." The development of clays for use as reinforcement in polymer nanocomposites is an option for these raw material producers, who would thus have a product with higher added value. This study aims to evaluate the potential use as nanofiller of two national clays from Taubaté basin, São Paulo, called ALIGRA and SANTA FE. In this experiment, the fractions of particles with average size of less than 0.02 obtained through wet sieving were used. The characterization studies involving granulometric, chemical, mineralogical, morphological, thermal and textural analysis, revealed very similar characteristics in both the clays. Clay fraction (< 2&#956;m) is higher 70%. Chemical composition as the definition of clay and its components show intermediate values between those present by bentonite and kaolinitic clays used here for purposes of comparison. It should be underlined good adsorptive properties. Specific surface area BET (aBET) around of 120 m2/g, this value is higher than showed by many bentonites (74.5 m2/g). They are predominantly mesoporous, the pores predominantly in slit-shape in accordance to the characteristic layered structure of the clays. Low cationic exchange capacities (CEC), 12 meq/100 g. XRD results for samples saturated with ethylene glycol and heated revealed the predominance of illite/smectite, kaolinite and quartz in ALIGRA clay, and illite, kaolinite and quartz in the clay SANTA FE. Work continued with the clay ALIGRA the preparation of organoclay. The organoclay was obtained by ion exchange with the quaternary ammonium salt: cetril trimethyl ammonium chloride, after homogenized in sodium with sodium chloride. FTIR and TGA analyzes indicated that there was integration of organic cations Preliminary tests were performed by preparing mixtures of clays with a polypropylene matrix, and using polypropylene grafted with maleic anhydride as a compatibilizer. Results of tensile tests made in the polypropilene- purified clay compositions have reported some improvements in some tested properties. With polipropilene-organofilized compositions only improved elongation on break. More detailed studies are which would be required.

Made available in DSpace on 2016-03-15T19:36:56Z (GMT). No. of bitstreams: 1 Thiago Ramos Stellin Malagrino.pdf: 4441654 bytes, checksum: 6ca4cb745da024c77c96b57a51ae6f04 (MD5) Previous issue date: 2016-01-26 / Polycarbonate, an amorphous engineering polymer, has excellent mechanical strength and although it s good chemical resistance, its interaction with some types of alkali and some organic solvents is weak. The main objective of this work was to study the effect of the inclusion of nanometric particle size of natural sodium clay (named Nanolite) and sodium clay treated with quaternary ammonium salt (named Cloisite 15A) in resin processing in order to investigate the variations in chemical properties, transparency and molecular structure. The characterization of nanocomposite was performed using methods of Scanning Electron Microscopy (SEM), Molar Mass Characterization by Mark-Houwink-Sakurada equation, Differential Scanning Calorimetry (DSC), Melt Flow Rate (MFR), Differential Thermal Analysis (DTA), Fourier Transform Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD) and Chemical Resistance obtained by the contact angle technique / Fowkes method. Optical, thermal, physical and chemical testing indicated that the molecular structure of PC after the inclusion of clays remained unchanged showing no irreversible degradation. The analysis of chemical resistance through the contact angle method showed significant improvement in the surface free energy of the nanocomposites when using the organoclay (Cloisite 15A) and partial improvement when used natural sodium clay (Nanolite). The decrease in surface free energy, indicates a likely improvement in the chemical resistance of the nanocomposites. / O Policarbonato, polímero de engenharia de estrutura amorfa, possui excelente resistência mecânica, e embora possua boa resistência química, deixa a desejar no que se refere ao contato com alguns tipos de álcalis e solventes orgânicos. O objetivo principal deste trabalho foi de estudar comparativamente o efeito da inclusão de partículas nanométricas de argila sódica natural (Nanolite) e argila sódica tratada com sal quaternário de amônio (Cloisite 15A), no processamento da resina a fim de investigar as variações ocorridas nas propriedades químicas e consequentemente, na transparência e estrutura molecular. A caracterização do nanocompósito foi realizada por meio de métodos de Microscopia Eletrônica de Varredura (MEV), massa molar calculada pela equação de Mark-Houwink-Sakurada, Calorimetria Diferencial por Varredura (DSC), Índice de Fluidez (IF), Análise Térmica Diferencial (DTA), Espectroscopia no Infravermelho por Transformada de Fourier (FTIR), Difração de Raios X (DRX) e Resistência Química calculada através da técnica de ângulo de contato / método de Fowkes. Os ensaios óticos, térmicos, físicos e químicos indicaram que a estrutura molecular do PC após a inclusão das argilas permaneceu inalterada, sem degradação irreversível. A análise da resistência química através do método de ângulo de contato apresentou significativa melhora na energia livre superficial dos nanocompósitos quando utilizada a argila organofílica (Cloisite 15A) e, melhora parcial quando utilizada a argila sódica natural (Nanolite). A queda da energia livre superficial, indica que existe uma provável melhora na resistência química dos nanocompósitos.

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Dans la perspective de prédire les transformations chimico-minéralogiques possibles d'une bentonite placée en conditions de stockage profond de déchets radioactifs, plusieurs séries d'expériences ont été réalisées utilisant la bentonite MX80 en présence d'une solution chlorurée sodi-calcique, en absence ou en présence de fer (magnétite + hématite ou fer métal + magnétite), à 80 et 300 °C et pour des durées de 1 jour à 9 mois. Les produits de réactions ont fait l'objet de caractérisations multi-échelles et multi-techniques : diffraction des rayons X, microscope électronique à balayage et en transmission (imagerie haute résolution, EDS et EELS), microsonde électronique, spectroscopie Mössbauer et analyse ICP AES et ICP MS des solutions. Le code de calcul EQ3/6 a été utilisé pour simuler les expériences réalisées. Une nouvelle méthode ponctuelle de détermination de la valence du fer dans les argiles au MET par spectroscopie de perte d'énergie des électrons (EELS) a été développée.

This thesis focuses on the synthesis and characterisation of organoclays. X-ray diffraction has been used to study the changes in the basal spacings of montmorillonite clay and surfactant-intercalated organoclays. Variation in the d-spacing was found to be a step function of the surfactant concentration. Three different molecular environments for surfactant octadecyltrimethylammonium bromide (ODTMA) within the surface-modified montmorillonite are proposed upon the basis of their different decomposition temperatures. High-resolution thermogravimetric analysis (HRTG) shows that the thermal decomposition of montmorillonite modified with ODTMA takes place in four steps attributing to dehydration of adsorbed water, dehydration of water hydrating metal cations, loss of surfactant and the loss of OH units respectively. In addition, it has shown that the decomposition procedure of DODMA and TOMA modified clays are very different from that of ODTMA modified ones. The surfactant decomposition takes place in several steps in the DODMA and TOMA modified clays while for ODTMA modified clays, it shows only one step for the decomposition of surfactant. Also TG was proved to be a useful tool to estimate the amount of surfactant within the organoclays. A model is proposed in which, up to 0.4 CEC, a surfactant monolayer is formed between the montmorillonite clay layers; up to 0.8 CEC, a lateral-bilayer arrangement is formed; and above 1.5 CEC, a pseudotrimolecular layer is formed, with excess surfactant adsorbed on the clay surface. While for dimethyldioctadecylammonium bromide (DODMA) and trioctadecylmethylammonium bromide (TOMA) modified clays, since the larger sizes of the surfactants, some layers of montmorillonite are kept unaltered because of steric effects. The configurations of surfactant within these organoclays usually take paraffin type layers. Thermal analysis also provides an indication of the thermal stability of the organoclay as shown by different starting decomposition temperatures. FTIR was used as a guide to determine the phase state of the organoclay interlayers as determined from the CH asymmetric stretching vibration of the surfactants to provide more information on surfactant configurations. It was used to study the changes in the spectra of the surfactant ODTMA upon intercalation into a sodium montmorillonite. Surfaces of montmorillonites were modified using ultrasonic and hydrothermal methods through the intercalation and adsorption of the cationic surfactant ODTMA. Changes in the surfaces and structure were characterized using electron microscopy. The ultrasonic preparation method results in a higher surfactant concentration within the montmorillonite interlayer when compared with that from the hydrothermal method. Both XRD patterns and TEM images demonstrate that SWy-2-Namontmorillonite contains superlayers. TEM images of organoclays prepared at high surfactant concentrations show alternate basal spacings between neighboring layers. SEM images show that modification with surfactant will reduce the clay particle aggregation. Organoclays prepared at low surfactant concentration display curved flakes, whereas they become flat with increasing intercalated surfactant. Fundamentally this thesis has increased the knowledge base of the structural and morphological properties of organo-montmorillonite clays. The configurations of surfactant in the organoclays have been further investigated and three different molecular environments for surfactant ODTMA within the surface-modified montmorillonite are proposed upon the basis of their different decomposition temperatures. Changes in the spectra of the surfactant upon intercalation into clay have been investigated in details. Novel surfactant-modified montmorillonite results in the formation of new nanophases with the potential for the removal of organic contaminants from aqueous media and for the removal of hydrocarbon spills on roads.