The search for a detailed understanding of the mechanism of zeolite synthesis has, over the past two decades, promoted many investigations into the species present in (alumino)silicate solutions. It is generally accepted that dissolved (alumino)silicate species are involved as precursors in the nucleation of zeolites. Several techniques have been employed to understand the mechanism of formation of these complex structures. NMR spectroscopy has been shown to be a very powerful tool for the detection and characterization of (alumino)silicate species in the solutions in question. This thesis presents a comprehensive study of certain silicate solutions employmg (^29)Si NMR which has extended the knowledge gained in previous studies. The role of structure-direction on the distribution of silicate species in silicate solutions is discussed, the results providing more understanding of this effect. The effects of pH, temperature, Si/cation ratio and silica concentration on the distribution of silicate anions were also studied.Aluminium-27 NMR was applied to investigate the local structure about alummium atoms in a series of alumino silicate solutions with Si:Al mole ratios pertinent to zeolite synthesis. The kinetics of the reaction of aluminate with silicate anions have been studied by investigating the temporal evolutions of (^29)Al NMR spectra and by 2D NMR exchange spectroscopy. Structural analyses of two new silicate crystals were carried out by single-crystal X-ray diffraction. Liquid- and solid-state NMR spectroscopy were employed to characterize the mother liquors, the powdered polycrystalline products, and their melts.The Zeolite SUZ-9 was characterized by application of multinuclear magnetic resonance spectroscopy : (^29)Si, (^27)Al, (^13)C and (^1)H NMR spectra of this zeolite were studied.

Texte remanié de: thèse--Sc. phys.--Paris, 1968. / Extrait du "Journal de chimie physique" T. 65, 1968, n° 6, pp. 1129-1140 . Conservé sous la cote : [4° V. 25892 (134)].

Cette étude s’inscrit dans le cadre du projet FE²E visant à développer un fusible plus économique et plus écologique. Ce travail a donc été réalisé selon un schéma allant de la caractérisation des matières premières à la fabrication de composants électriques à l’aide de matériaux géopolymères. La réactivité des solutions de silicate a été déterminée par spectroscopies infrarouge, Raman et résonance magnétique nucléaire. Les interactions entre les solutions et du sable ont ensuite été étudiées selon différentes méthodes d’imprégnation et différents types de séchage, afin d’optimiser les propriétés mécaniques des blocs de sable aggloméré. Le remplacement des corps de fusible par des liants géopolymères a été envisagé par la création d’un dépôt ou par coulage du liant. Ensuite, la validation des propriétés thermiques des liants et les interactions entre un liant et une surface métallique ont permis d’envisager une rupture technologique. Finalement, il a été démontré qu’il était possible d’obtenir un fusible ou un busbar à base de liants géopolymères. / This study is a part of the FE²E project and was accomplished in order to develop an economic and ecologic fuse. The methodology covers different steps going from the raw materials characterization to the manufacturing of electrical components (as fuse and busbar) with geopolymer materials. The reactive species in alkaline solutions were determined by FTIR, NMR and Raman spectroscopies. Then, the interactions between the sand and the solutions were studied using various impregnation and different curing methods in order to optimize the mechanical properties of agglomerated sand. Fuse body replacement by geopolymer binders by a coating or by casting in a mold were considered. Then, the validation of the thermal properties by thermal treatment and the interactions between a geopolymer binder and a metallic surface conduce to a technological disruptive. Finally, the possibility to obtain a geopolymer-based fuse or busbar was clearly evidenced.

Ce travail est basé sur l’étude la qualité de matières premières argileuses utilisées dans la production de briques en terre cuite ainsi que sur la valorisation de ces matières premières dans les liants géopolymères. Une première étape a consisté à caractériser par des techniques de caractérisations physico-chimiques, structurales, et thermiques plus de 30 matières premières. Ceci a permis de réaliser des abaques à partir des corrélations issues des aptitudes favorables ou mauvaises dans la production de brique. Parallèlement, des investigations sur la présence de fer et de kaolinite / muscovite ont été menées et ont permis d’évaluer la localisation du fer dans ces différents prélèvements. Dans un second temps, une étude associée à la valorisation de ce mélange de production dans les liants géopolymère a été mis en œuvre. Différentes sources aluminosilicates, de température de calcination différente, ont été utilisées. La caractérisation lors de la consolidation par spectroscopie IRTF a alors mis en évidence des réactions de polycondensation et la formation de liaisons Si-O-Ca. La synthèse de liant géopolymère avec addition de calcium dans un mélange de production a alors révélé des interactions différentes selon le type de cation alcalin (sodium, potassium) de la solution de silicate. La revalorisation de ces matières premières dans de nouveaux produits innovants, substituant les agrégats d’argile expansée, a été réalisée. / This study is based on the investigation of the brick clay quality and on their valorization in a geopolymer binder. First, numerous clay samples were analyzed by physical, chemical, structural and thermal characterizations, which led to abacus plots, allowing to distinguish an efficient or a non-suitable clay for the bricks production. Simultaneously, the iron interaction with the clay minerals was established. An experimental protocol was determined for the company to determine the clay quality for a brick production. Then, a feasibility study of the valorization of these clay minerals in a geopolymer binder was conducted. The FTIR study highlighted a polycondensation reaction and a reaction with the calcium, which was more or less important according to the alkali cation type of the silicate solution. An alternative to the lightweight expanded clay aggregates was evidenced, with the revalorization of brick clay materials in a lightweight geopolymer product.

abstract: This study evaluates the use of plant-extracted silica solution as a bio-based grout material for improvement of granular soils. Although silicate grout is a very well-established and popular technique in the ground improvement market, efforts have been initiated to replace chemically-synthesized silicate grout with plant-extracted silica grout. This initiative will increase the level of sustainability and consequently improve the existing market acceptability. The silica-rich plant source used for extraction was rice husk, which is an abundantly produced agricultural waste. The extraction method includes acid-leaching, temperature-controlled rice husk ash production and the preparation of an aqueous sodium silicate solution from the ash through an alkaline leachate method. Silica ash was in amorphous form containing 95% of silica content which is suitable for soil treatment. Gelation time was controlled in the absence and presence of sand under different pH values. Bio-based silica grouting showed an improvement of the shear strength of the soil as well as the hydraulic conductivity reduction. / Dissertation/Thesis / Masters Thesis Civil, Environmental and Sustainable Engineering 2019