L’eau est le principal vecteur responsable de la dégradation du patrimoine bâti. L’un des moyens utilisé, pour réduire la pénétration de l’eau dans la pierre est la bioremédiation. Il se base sur la capacité des bactéries à former des biocristaux. Ce concept a été utilisé par la société Calcite Bioconcept avec la souche Bacillus cereus. Par le passé, l’action bactérienne et, en particulier, la possibilité de créer des cristaux a été étudiée et mise en évidence en milieu aqueux, très favorable à la croissance bactérienne. L’originalité de cette thèse est de reprendre ces études en suivant le même protocole qui celui utilisé in situ et d’étudier le résultat de la bioremédiation sous différents aspects physique, chimique et biologique. Différents supports ont été adoptés, des tuffeaux (pierre calcaire pour lequel le biotraitement a été mis au point) et du plâtre. Les images MEB, sur des échantillons fracturés, montrent la formation d’un biofilm à la seule surface du matériau. Aussi des méthodes d’investigation de surface ont été menées (cathodoluminescence, DRX en incidence rasante). Cette dernière technique confirme la formation de calcite à la surface des échantillons de plâtre. Les cycles d’imbibition et des mesures de perméabilité montrent la réduction des coefficients de transport (ce qui est un effet attendu et souhaité du traitement). Cependant, l’augmentation de la vitesse d’imbibition au fur et à mesure des cyclages laisse penser que le biofilm se dégrade rapidement. Enfin, une alternative au protocole industriel, utilisé précédemment, est proposée, non plus basée sur les capacités de la membrane des bactéries à synthétiser des cristaux de calcite, mais par leurs EPS. / Degradation of historical buildings is mainly due to water intrusion that is the main vector ofpollutants. Differents types of surface treatment were proposed to avoid or limit this effect. As analternative of chemical treatment, the use of the carbonatogenesis property of some bacteria wasproposed. In the past, The bacterial production was pointed out on concrete and on limestonesamples in an aqueous environment. Moreover, the carbonate production was indirectly measuredand the experimental protocol was far from real use conditions.In this thesis, we follow the same protocol as an industrial one used in situ and study with chemical,physical as well as biological approaches the bioremediation effects on different porous samples:limestone (for which the treatment has been optimized) and plastrum.We confirm that, indeed, the bioremediation results in a thin biocoating (around 10 micrometer depth)formed on the surface of the treated samples. So, different surface analyses have been performed,on micro scale (GIXD, electronic microprobe), on macro scale (cathodoluminescence).The formershows the structural and morphological evolution of the produced carbonate coating and that indeedcalcite is produced by the treatment on model plaster samples. This substrate was chosen in order tounambiguously point out the bacterial carbonate production.The latter confirms the presence ofcalcite and the homogeneity of the coating at this scale. The reduction and durability of the biofilmhas been evaluated by imbibition cycles as well as permeability measurements.The biotreatment presents some drawbacks that could be avoided using the EPS only. Differentscrystals have been synthetized using organic mater. The influence of this organic matter on thecrystals shape and size has been studied.

Motivated by a desire to understand the basic concepts of one-dimensional nanostructure growth, the research described in this thesis aims at understanding the basic mechanisms controlling the synthesis and formation of a specific group of II-VI semiconducting nanostructures. In particular, this thesis examines one-dimensional nanostructures (such as nanobelts and nanowires) and different morphologies of ZnS that result from the interesting properties that the materials have at the nanoscale. In order to understand how to tune these properties in the nanostructure, it is necessary to have an understanding of the growth mechanism that dictates the morphology, structure, and rate of growth of the nanomaterial. It is necessary to understand what impact changes to the macroscopic setup in the experiment have on the nanoscopic scale of the nanomaterials. Having a larger understanding and exerting more precise control over the growth of nanomaterials will allow a higher level of selectivity, more control over dimensionality and the type of morphology, easier manipulation, and the simpler incorporation of these structures into a nanotechnological device. The main focus of the research was on CdSe and ZnS, with the bulk of the research being conducted on ZnS nanostructures. These materials were chosen for their potential for extensive research, their possible applications in optoelectronics, their potential to form the wurtzite crystal structure, and the potential generalization of results to other nanomaterials. The framework for the research is given first. Then a description of the experimental setup and a model for the growth of nanostructures is discussed. A brief overview of the synthesis of CdSe nanostructures is given and then a detailed analysis of the synthesis of specific ZnS one-dimensional morphologies is presented.

abstract: Among the alternative processes for the traditional distillation, adsorption and membrane separations are the two most promising candidates and metal-organic frameworks (MOFs) are the new material candidate as adsorbent or membrane due to their high surface area, various pore sizes, and highly tunable framework functionality. This dissertation presents an investigation of the formation process of MOF membrane, framework defects, and two-dimensional (2D) MOFs, aiming to explore the answers for three critical questions: (1) how to obtain a continuous MOF membrane, (2) how defects form in MOF framework, and (3) how to obtain isolated 2D MOFs. To solve the first problem, the accumulated protons in the MOF synthesis solution is proposed to be the key factor preventing the continuous growth among Universitetet I Oslo-(UiO)-66 crystals. The hypothesis is verified by the growth reactivation under the addition of deprotonating agent. As long as the protons were sufficiently coordinated by the deprotonating agent, the continuous growth of UiO-66 is guaranteed. Moreover, the modulation effect can impact the coordination equilibrium so that an oriented growth of UiO-66 film was achieved in membrane structures. To find the answer for the second problem, the defect formation mechanism in UiO-66 was investigated and the formation of missing-cluster (MC) defects is attributed to the partially-deprotonated ligands. Experimental results show the number of MC defects is sensitive to the addition of deprotonating agent, synthesis temperature, and reactant concentration. Pore size distribution allows an accurate and convenient characterization of the defects. Results show that these defects can cause significant deviations of its pore size distribution from the perfect crystal. The study of the third questions is based on the established bi-phase synthesis method, a facile synthesis method is adopted for the production of high quality 2D MOFs in large scale. Here, pyridine is used as capping reagent to prevent the interplanar hydrogen bond formation. Meanwhile, formic acid and triethylamine as modulator and deprotonating agent to balance the anisotropic growth, crystallinity, and yield in the 2D MOF synthesis. As a result, high quality 2D zinc-terephthalic acid (ZnBDC) and copper-terephthalic acid (CuBDC) with extraordinary aspect ratio samples were successfully synthesized. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2019

Crystal engineering underlies the essence of natural affiliation between the molecule on the one side and the crystal as a supramolecular assembly on the other. Molecular recognition is the fundamental cause for this efficient transformation and if we consider the crystal as a supramolecular entity then it is not at all difficult to conceive crystallization as an outstanding example of molecular recognition. In general, organic compounds often facilitate closed packed crystal structures as described by A. I. Kitaigorodskii in the form of the close packing principle but based on chemical features, there is still a small window to understand, to rationalize and to fashion new crystal structures. Extending the chemical viewpoint as first proposed by J. M. Robertson, the supramolecular synthon model as a descriptor of collective crystal structures has been invoked that enables one to trail the molecular behaviour from an entropy dominated situation in solution to an enthalpy driven progression in the solid state. After 20 years, the concept of the supramolecular synthon has stood the test of time because of its simplicity and effectiveness towards the implementation in complex crystal structures and has led the scientific community to further handle complex and interesting ideas in structural chemistry and supramolecular synthesis. The complexity of dynamic and progressive behavior of molecules during crystallization may be understood by the analogous argument of protein folding; both these complex phenomena decode the emergence of multiple metastable forms before the final structures are attained. These intermediate kinetically driven species may be high energy polymorphs and pseudopolymorphs of the compound in question or semicompact random globules for proteins. Understanding the role of these species in their respective processes is of critical importance in elucidating mechanisms. As an alternative approach, crystal structure prediction (CSP) is also of fundamental importance in the context of understanding the crystallization process. All energy based computational methods of CSP address this problem by scanning the multi-dimensional energy hypersurface. This is performed by computing lattice energy changes with respect to parameters like unit cell dimensions, space group symmetry and the positional coordinates of atoms in the asymmetric unit. Further, the computational prediction of the crystal structure of an organic compound results in several choices, and it is possible that a collection of some of these when taken together forms a pattern that mimics the course of the crystallization process very much in the manner that structure correlation mimics covalent bond breaking and making. With all these developments, one is truly at the stage today when any experimental or computed crystal structure is just that, a crystal structure of the molecule in question and it is part of a complex and dynamic structural space which may include a part of the supramolecular reaction trajectory for crystallization itself. Accordingly, this thesis emphasizes the importance of kinetic events during crystallization and proposes some strategies to access the inaccessible domains of this structural space of a given compound. I have exploited the supramolecular synthon model to understand the kinetics of the crystallization process and have further extended this understanding towards the isolation of stoichiometric ternary solids. The synthon model also helps one to provide a logical step to explore these remote domains of the complex hyperenergy surface that have collectively been termed as the crystal structure landscape of the compound in question. The precise descriptions of the chapters are mentioned below. Chapter 2 describes fluorosubstitution as a unique chemical probe to explore the high energy crystal structures of benzoic acid in ambient conditions. This landscape exploration of benzoic acid is based on the robust (kinetically favoured) supramolecular homosynthon as well as consistent fluorosubstitution in native compound. This analysis is also supported by synthon based crystal structure prediction which is one of the best ways of monitoring high energy virtual crystal structures. Chapter 3 extends the idea of landscape exploration towards multicomponent systems. The incorporation of an additional compound during crystallization facilitates even complex kinetic environments but using fluorosubstitution as a chemical probe, it again helps to analyse the high energy virtual domains of the given multicomponent system. Similar to chapter 2, the landscape exploration of multicomponent system is also based on the robust (kinetically favoured) supramolecular heterosynthon as well as consistent fluorosubstitution in the native multicomponent system. Chapter 4 emphasizes the importance of synthon modularity as a chemical probe to traverse in the crystal structure landscape of the given multicomponent system. Here, I have quantified the role of the definitive synthon, by using the supramolecular synthon based fragment approach (SBFA), in the emergence of polymorphism in cocrystals. In latter part of this chapter, I utilized this collective kinetic information in order to realize the combinatorial nature of the crystallization process and showed the complex combinatorial synthesis of ternary solids which itself is considered to be an arduous exercise. Chapter 5 discusses the importance of kinetic information which were fetched from the corresponding multicomponent landscapes and were further utilized for combinatorial synthesis of ternary solids. Although the combinatorial idea is well established in solution, this chapter highlights the first experimental evidence of this idea in the solid state and shows preferred amplification of certain supramolecular synthons from corresponding libraries in the supersaturated crystallizing medium. Chapter 6 extends the combinatorial idea of crystallization even further by using highly flexible organic compounds that collectively provide larger structural space during crystallization. Using the delicate kinetic information about the molecular and supramolecular features, this chapter describes the preferential selection of molecular conformation and supramolecular synthons from the supersaturated solution during the molecule→crystal pathway. In summary, the idea of the crystal structure landscape provides an extended interpretation about some of the complex ideas namely, crystal energy landscape and polymorphism in modern crystal engineering. The crystallization of an organic compound often depends upon intrinsic chemical features and accordingly one selects optimized crystallization routes in the corresponding landscape through decisive experimental conditions. As a final note, the idea of the crystal structure landscape enables one to (at least qualitatively) understand the importance of crystallization kinetics which is understandably a difficult task.

La thèse porte sur la synthèse et l'étude des propriétés magnétiques de borates de fer-gallium,FexGa1-xBO3 avec 0 supérieur ou égal à x supérieur ou égal à 1. Ces matériaux sont prometteurs pour les applications; en plus, grâce à la présence, en fonction de x, de différents types d’ordre magnétique, ils sont bien adaptés au traitement de nombreux problèmes du magnétisme des solides.Le borate de fer, FeBO3 est un antiferromagnétique possédant un plan de facile aimantation et un faible ferromagnétisme. Les caractéristiques du borate de fer sont radicalement modifiées par substitution isomorphe fer – gallium diamagnétique.Nous avons mis au point une route de synthèse de monocristaux FexGa1-xBO3 de haute qualité. Comme principales techniques expérimentales, nous avons choisi les résonances magnétiques électronique (RME) et nucléaire (RMN). Selon le contenu du fer, nous avons observé:(i) la résonance antiferromagnétique, (ii) la résonance de clusters magnétiques et (iii) la résonance paramagnétique électronique (RPE). Les différents états magnétiques ont été identifiés et leurs caractéristiques – la température de Néel, le champ de Dzyaloshinskii-Moriya; les paramètres de l’hamiltonien de spin de Fe3+, etc.– ont été déterminées. La coordinence et la symétrie de sites de 11B et 71Ga ont été précisées par RMN à rotation sous l’angle « magique » (MAS). Moyennant la simulation des spectres de RPE et de MAS RMN, à l’aide de codes mis au point ad hoc, les distributions de paramètres dues au désordre local ont été déterminées. L’analyse théorique, tenant compte de contributions du champ cristallin et de l’interaction dipôle-dipôle, permet d’expliquer l’anisotropie magnétocristalline de volume et de surface. / The thesis is concerned with synthesis and studying magnetic properties of iron-galliumborates, FexGa1-xBO3 with [0 supérieur ou égal à x supérieur ou égal à 1]. These materials are promising candidates for applications;besides, occurrence of different types of magnetic ordering, depending on x, makes them suitablefor treating a number of fundamental problems in solid state magnetism.Iron borate, FeBO3 is a two-sublattice easy-plane antiferromagnet with weakferromagnetism. Physical characteristics of iron borate are radically modified by isomorphoussubstitution of a part of iron by diamagnetic gallium.We have started with developing a synthesis route for growing high-quality FexGa1-xBO3single crystals. As main experimental techniques, we have chosen Electron and Nuclear MagneticResonances (EMR, NMR). Depending on iron contents and temperature, we have observed:(i) Antiferromagnetic, (ii) Cluster Magnetic and (iii) Electron Paramagnetic Resonance (EPR).Different magnetic states have been identified and their characteristics: Néel temperature,Dzyaloshinskii-Moriya field; spin Hamiltonian parameters of isolated Fe3+ ion, etc., have beendetermined. Coordination and site symmetry of 11B and 71Ga nuclei have been specified by meansof Magic Angle Spininng (MAS) NMR. Carrying out computer simulations of EPR and MASNMR spectra with laboratory-developed codes, the parameter distributions caused by localdisorder have been determined. Theoretical analysis taking into account crystal field and dipoledipolecontributions allow interpreting volume and surface magnetocrystalline anisotropy of thecrystals.