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Studying calcium carbonate (otoliths) and calcium phosphate (fins, scales, bones) hard structure chemistry has numerous applications in the fisheries field for both freshwater and marine environments. The overall thesis objectives were: 1.) to provide an integrated and multidisciplinary approach to understanding the incorporation of trace elements and isotopes into biomineralized hard structures, and 2.) to apply this multidisciplinary perspective in the examination of element marking, stock discrimination, and migration in teleost fish species found within the Canadian Polar North. Varying physiological mechanisms within fishes control the uptake of essential and non-essential trace elements and isotopes during biomineralization processes. Essential life elements such as zinc and magnesium are controlled by their own uptake regulation systems whereas non-essential elements such as strontium and barium are controlled primarily by calcium uptake at the gills driven by internal calcium homeostasis. Secondarily, environmental trace elements compete with calcium and with each other for uptake at the gills. The ability of certain hard structures such as bones, fins, and scales to remobilise calcium and associated calcium-like elements, plays a role in the prolonged high concentrations of strontium that were observed in otolith marking of Greenland Halibut, Reinhardtius hippoglossoides. High doses of strontium chloride resulted in a prolonged expulsion of excess strontium. Strong associations of Dolly Varden Char, Salvelinus malma malma, with groundwater allowed discrimination of populations among studied river systems using otolith strontium and barium, and strontium isotopes. Calculation of otolith strontium freshwater baselines allowed for a quantitative method to examine migration histories of Arctic Char, S. alpinus, in Canada and western Greenland. Migration seaward was related to ease of access to estuary and marine habitats. Easy access to estuaries resulted in migration at a young age and small size whereas longer rivers resulted in a delay of migration to older ages and larger sizes. Understanding the role of fish physiology in association with calcium homeostasis provided a stronger basis for understanding the incorporation and presence of trace elements and isotopes found within biomineralized hard structures. These studies underscore the utility of microchemical studies for elucidating biological phenomena, thus linking the aspects of biology, physiology, and geology. / February 2017

On appelle biominéraux l’ensemble des minéraux fabriqués par le vivant. Ce sont des matériaux essentiels, présents dans la quasi-totalitédes espèces vivantes. Néanmoins les caractéristiques structurales, chimiques ainsi que les mécanismes de formation, et l’évolution de cesmatériaux sont encore fortement débattus. Cela s’explique notamment par les difficultés à étudier expérimentalement des espèces chimiquesévoluant en milieux biologiques.Bien que tout aussi complexe, une approche théorique, à l’échelle moléculaire, peut aider à la caractérisation de ces matériaux biologiqueset notamment la caractérisation de leurs interfaces formées avec les milieux biologiques environnants. Cela étant essentiel pour une meilleurecompréhension de la formation et de l’évolution de ces minéraux.Les oxalates de calcium constituent une famille de biominéraux très importante dans le monde du vivant. Ils constituent notamment les principales espèces cristallinesrencontrées dans les calculs rénaux où ils peuvent exister sous trois phases possédant différents degrés d'hydratation. Au cours de cette thèse, nous avons effectuéles simulations des propriétés spectroscopique IR et RMN des ces trois phases, ce qui permet d'obtenir une signature propre à chacune d'entre elle, aidant ainsi àl'identification de ces phases à partir des spectres obtenus expérimentalement.Les phosphates de calcium font aussi partie des biominéraux. Ils composent la majeure partie du minéral osseux des mammifères. Ce minéral se trouvesous la forme de nanoparticules décrites comme possédant un cœur cristallin d’hydroxyapatite substituées entourée d'une couche hydratée et désordonnée en surface.Durant ce travail de thèse, nous nous sommes intéressés à ces deux composantes. Concernant le cœur cristallin des particules, nous avons étudié en particulierle cas des substitutions par des carbonates car il s'agit de la substitution prédominante dans les apatites biologiques. En couplant ce travail à des expériencesde RMN solide nous pouvons proposé une localisation précise de ces substituants au sein de la maille d’hydroxyapatite.La couche désordonnée de surface est encore très mal comprise à l'heure actuelle et de nombreux modèles structuraux sont proposés dans la littérature pour la décrire. Nous avonsconsidéré un certain nombre d'entre eux pour lesquels nous avons modélisé les propriétés RMN, qui confrontées à celle issues de l'expérience nous ontpermis d'identifier les points forts et faibles des différentes hypothèses. / Biominerals are all the minerals produced by living organisms. They are essential materials, present in almost all living species. Nevertheless,the structural, chemical properties and, formation mechanisms and the evolution of these materials are still heavily debated. This is due in particular to thedifficulties of experimentally studying chemical species evolving in biologicalenvironments. Although, equally complex, a theoretical approach at the molecular level can help in the characterization of these biological materialsand in particular the characterization of their interfaces formed with the surrounding biological media. This is essential for a better understandingof the formation and evolution of these minerals.Calcium oxalates are essential biominerals that are very common in the living world. They constitute the main crystalline speciesencountered in kidney stones where they can exist in three phases possessing different degrees of hydration. In this, thesis we carried outsimulations to predict the IR and NMR spectroscopic properties of these three phases. Thsi enabled us to obtain specificsignature of each polyhydrate, and thus makes it possible to obtain a signature specific to each of them, thus helpingthe identification of these phases from the experimentally spectra obtained.Calcium phosphates are part of the bio/biological minerals. They make up the major part of the bone mineral of mammals. This mineral is in the form of nanoparticles havinga crystalline core of hydroxyapatite and a hydrated and disordered surface layer.During this thesis we were interested in these two components. Concerning the crystalline core of the particles, we studied in particularthe case of carbonate substitutions because of its predominant substitution in biological apatites. By combining this work with solid state NMR experimentswe can propose a precise localization of these substituents within the hydroxyapatite crystalline cell.The disordered surface layer is still very poorly understood and many structural models are proposed in the literature to describe it. We haveconsidered a number of them for which we have modeled the NMR properties which were then confronted with experimental results. The comparaisonmade it possible to identify the strengths and weaknesses of the various hypotheses.

Biomineral composites, consisting of intercrystalline organics and biogenic minerals, have evolved unique structural designs to fulfill mechanical and other biological functionalities. Aside from the intricate architectures at the composite level and 3D assemblies of the biomineral building blocks, the individual mineral blocks enclose intracrystalline structural features that contribute to the strengthening and toughening at the intrinsic material level. Therefore, the design strategies of biomineralized composites can be categorized into two structural levels, the individual building block level and the composite level, respectively. This dissertation aims at revealing the material design strategies at both levels for the bioinspired designs of advanced structural ceramics. At the building block level, there is a lack of comparative quantification of the mechanical properties between geological and biogenic minerals. Correspondingly, I first benchmark the mechanical property difference between biogenic and geological calcite through nanoindentation techniques. The selected biogenic calcite includes Atrina rigida prisms and Placuna placenta laths, corresponding to calcite {0001}, and {101 ̅8} planes. The natural cleavage plane {101 ̅4} of geological calcite was added to the comparative study. Under indentation load, geological calcite deforms plastically via twinning and slips under low loads, and shifts to cleavage fracture under high loads. In comparison, the P. placenta composites, composed of micro-sized single-crystal laths and extensive intercrystalline organic interfaces, exhibit better crack resistance. In contrast, the single-crystal A. rigida prisms show brittle fracture with no obvious plastic deformation. Secondly, how the internal microstructures and loading types affect the mechanical properties of individual building blocks is investigated. The prismatic building blocks are obtained from the bivalves A. rigida and Sinanodonta woodiana, where the former consists of single-crystal calcite and the latter consists of polycrystalline aragonite. The comparative investigation under different loading conditions is conducted through micro-bending and nanoindentation. The continuous mineral matrix in A. rigida prisms leads to comparable modulus under tensile and compressive loadings in the elastic regime, while the high-density intracrystalline nanoinclusions contribute to the conchoidal fracture behaviors (instead of brittle cleavage). In comparison, the interlocking grain boundaries in S. woodiana prisms correlate with easier tensile deformation (smaller tensile modulus) than compression, as well as the intergranular fracture morphologies. The third topic in the biomineral-level investigation focuses on how biomineral utilizes residual stress at the macroscopic scale. The selected model system is the spine from the sea urchin Heterocentrotus mamillatus, which has a bicontinuous porous structure and mesocrystalline texture. It is confirmed that the spine has a macroscopic stress field with residual tension in the central medulla and compression in the radiating layers. The multimodal characterizations on the spine conclude that the structural origins are not associated with the gradient distribution of the intracrystalline defects, including Mg substitution in the calcite matrix, intracrystalline organics, and amorphous calcium carbonates (ACC). It is hypothesized that the residual stress is generated due to the volume expansion during ACC crystallization at the compacted growth front. At the composite level, even though enhanced crack resistance is expected in biomineralized composites due to their hierarchical structures, the correlation between their 3D composite structures and damage/crack evolution is quite limited in the literature. I developed in-situ testing devices integrated with synchrotron-based X-ray tomography to capture the crack propagation in the materials, including the four-point bending and compression/indentation configurations. Two representative models are chosen to demonstrate the deformation of biomineralized composites under bending and compression, respectively, including the calcium carbonate-based gastropod shell (Melo diadema) and the hydroxyapatite-based fish teeth (Pogonias cromis). Also, the two composites are designed to achieve different functional requirements, i.e., enhanced fracture toughness vs. wear resistance. The comprehensive characterizations of these two composites revealed how biological structural composites are designed accordingly to their functional needs. For the crossed-lamellar M. diadema shell, directional dependence of the shell property was revealed, where the transversal direction (perpendicular to the growth line) represents both the stronger and tougher direction, but the longitudinal direction is more resistant to notches and defects. For the P. cromis teeth, the enhanced wear resistance of the near-surface enameloid originates from the intricate designs at the microscale, with c-axes of hydroxyapatite crystals and micro-sized enameloid rods coaligned with biting direction and F and Zn doping. In addition, the fracture morphologies of the fish teeth correlate with the microstructures; the enameloid exhibits corrugated fracture paths due to the interwoven fibrous building blocks, and the dentin exhibits clean planar fracture surfaces. / Doctor of Philosophy / Ceramic materials have wide applications in daily life and advanced technologies, and examples range from kitchenware (e.g., cups and plates) to spacecraft (e.g., thermal coating). These materials have indispensable applications due to their advantages of high strength and hardness, high heat and corrosion resistance, lightweight, chemical inertness, etc. Yet, intrinsic brittleness usually limits their applications. Typical ways to enhance the toughness of ceramics involve microstructure design (by refining the sizes and shapes of grains) and transformation toughening (phase transition) at the individual grain level, composite reinforcement (or ceramic matrix composites) at the composite level, and introducing residual stress to impede crack initiation and propagation. The engineering methods usually involve high energy input, chemical treatment, and usually significant waste and non-ecofriendly emissions. Therefore, learning the design strategies from biological ceramic solids constructed by organisms wound provide valuable insights into enhancing the performance of ceramics while reducing the harmful impact on the environment. In this dissertation, I investigated the mechanical design strategies from natural 3D biomineralized composites from two structural levels, i.e., building-block and composite levels, analogous to individual grains and composite reinforcement in engineering ceramics. For the building-block level research, the model systems include bivalve shells Atrina rigida, Placuna placenta, and Sinanodonta woodiana. The three bivalve shells contain different building blocks with intrinsic microstructures, corresponding to monolithic prisms with controlled nanoinclusions, diamond-shaped thin laths, and polycrystalline prisms with interlocking grains, respectively, presenting different structural designs of individual grains in ceramic materials. The sea urchin Heterocentrotus mamillatus spine represents a natural porous material with compressive residual stress on the surface, and the investigation of the structural origins aims to provide insights into the cost-effective synthesis of stressed ceramics with residual stress for engineering applications. In addition, the composite-level studies focus on the composite structures of the crossed-lamellar shell Melo diadema and the fish teeth from Pogonias cromis. These two model systems correspond to natural ceramic matrix composites with nano-scale fibrous building blocks arranged in 3D specialized for enhanced crack resistance and wear resistance, respectively. The comprehensive investigation of the deformation behaviors and mechanisms allows for a better understanding of the intricate strategies specialized for different functional requirements, which apply to bio-inspired designs in ceramic composites.