Synthesis and characterization of nanostructured biomaterials suitable for bone regeneration

Traballo fin de grao (UDC.CIE). Química. Curso 2016/2017[Resumo] Neste Traballo de Fin de Grao estudouse a síntese por vía húmida de fosfato cálcico bifásico (formado por hidroxiapatita e β-fosfato tricálcico). Leváronse a cabo tamén as sínteses de óxido de sílice mesoporoso e de nanopartículas de titanato de bario para a súa posterior adición, por separado, ao fosfato cálcico bifásico, coa fin de variar as propiedades do material biocerámico de cara a favorecer a capacidade de osteoinducción e a integración do biomaterial no medio biolóxico. A caracterización dos materiais sintetizados fíxose mediante as técnicas de: espectrometría infravermella por transformada de Fourier (FTIR), difracción de raios X de po (DRX), microscopía óptica, microscopía electrónica de varrido (SEM), microscopía electrónica de transmisión (TEM) e análise termogravimétrica (TGA). Como resultado, sintetizouse o BCP coa composición, estrutura e morfoloxías desexadas, así como o SiO2 mesoporoso, as nanopartículas de BaTiO3 e os compostos de BCP-SiO2 e BCP-BaTiO3, tamén coa composición, estrutura e morfoloxías desexadas, polo que se espera que sexan aptos para poder incorporarse ao tecido biolóxico e favorecer a rexeneración ósea.[Resumen] En este Trabajo de Fin de Grado se estudió la síntesis por vía húmeda de fosfato cálcico bifásico (formado por hidroxiapatita y β-fosfato tricálcico). Se llevaron a cabo también las síntesis de óxido de silicio mesoporoso y de nanopartículas de titanato de bario para su posterior adición, por separado, al fosfato cálcico bifásico, con el fin de variar las propiedades del material biocerámico de cara a favorecer la capacidad de osteoinducción y la integración del biomaterial en el medio biológico La caracterización de los materiales sintetizados se hizo mediante las técnicas de: espectrometría infrarroja por transformada de Fourier (FTIR), difracción de rayos X de polvo (DRX), microscopía óptica, microscopía electrónica de barrido (SEM), microscopía electrónica de transmisión (TEM) y análisis termogravimétrico (TGA). Como resultado, se sintetizó el BCP con la composición, estructura y morfologías deseadas, así como el SiO2 mesoporoso, las nanopartículas de BaTiO3 y los compuestos de BCP-SiO2 y BCP-BaTiO3, también con la composición, estructura y morfologías deseadas, por lo que se espera que sean aptos para poder incorporarse al tejido biológico y favorecer la regeneración ósea.[Abstract] In this Final Grade Project, it was studied the synthesis of biphasic calcium phosphate (formed by hydroxyapatite and β-tricalcium phosphate) by a wet method. Additionally, it was synthesized mesoporous silicon dioxide and barium titanate to be added, separately, to the biphasic calcium phosphate, with the purpose of varying the properties of the bioceramic material for favour its osteoinducion capacity and the integration of the biomaterial in the biologic medium. The characterization of the synthesized materials was carried out by the techniques of: Fourier-transform infrared spectroscopy (FTIR), powder X-Ray diffraction (XRD), optical microscopy, scanning electron microscopy (SEM), transmission electron spectroscopy (TEM) and thermogravimetric analysis (TGA). As a result, BCP, mesoporous SiO2, nanoparticles of BaTiO3 and the composite materials of BCP-SiO2 and BCP-BaTiO3 were synthesized with the suitable composition, structure and morphology, so it’s expected that they would be suitable to be incorporated in the biological tissue and to favour the bone regeneratio

Design and rheological study of ceramic materials for 3D printing

[Resumo]: Actualmente, a impresión en 3 dimensións (3D) é unha tecnoloxía moi útil para producir novas formas e estruturas, cun amplo rango de aplicacións, tales como produción industrial, biomedicina, enxeñaría e incluso arte. A importancia de poder imprimir diferentes materiais está motivando a investigación e desenrolo de diferentes métodos e tipos de tintas de impresión. No presente Traballo de Fin de Máster descríbese o estudo realizado para o deseño de materiais cerámicos e o seu estudo reolóxico de cara a analizar a súa viabilidade en impresión 3D. O obxecto de estudo deste TFM foron un par de arxilas porcelánicas comerciais, que foron caracterizadas mediante Difracción de Raios X (XRD) de po, Análise Termogravimétrica (TGA), Espectroscopía Infravermella (IR) e Microscopía Electrónica de Varrido (SEM) e de Transmisión (TEM). Deseñouse un estudo reolóxico das suspensións de porcelana en auga que permitise coñecer as propiedades físicas máis implicadas no proceso de impresión 3D (viscosidade aparente, módulo elástico, módulo viscoso e a súa variación coa velocidade de cizalla e co tempo) e levouse a cabo dito estudo reolóxico en diferentes mesturas porcelánicas, variando factores como a proporción de auga e o tempo de repouso. De cara a mellorar a viabilidade das porcelanas para a impresión 3D, modificáronse as propiedades do fluído soporte, mesturando a auga con diferentes compostos: silicato sódico, un coñecido axente tixotrópico (fluidificante), nanotubos de carbono e etanol. Os resultados do estudo realizado sobre a porcelana e os axentes que se lle introduciron foron testados nunha impresora 3D con sistema de extrusión, corroborando o efecto positivo do silicato sódico na mestura e o efecto óptimo do etanol, que resultou ser o previsiblemente máis axeitado.[Resumen]: Actualmente, la impresión en 3 dimensiones (3D) es una tecnología muy útil para producir nuevas formas y estructuras, con un amplio rango de aplicaciones, tales como producción industrial, biomedicina, ingeniería e incluso arte. La importancia de poder imprimir diferentes materiales está motivando la investigación y desarrollo de diferentes métodos y tipos de tintas de impresión. En el presente Trabajo de Fin de Máster se describe el estudio realizado para el diseño de materiales cerámicos y su estudio reológico de cara a analizar su viabilidad en impresión 3D. El objeto de estudio de este TFM fueron un par de arcillas porcelánicas comerciales, que fueron caracterizadas mediante Difracción de Rayos X (XRD) de polvo, Analísis Termogravimétrico (TGA), Espectroscopía Infrarroja (IR) y Microscopía Electrónica de Barrido (SEM) y de Transmisión (TEM). Se diseñó un estudio reológico de las suspensiones de porcelana en agua que permitiese conocer las propiedades físicas más implicadas en el proceso de impresión 3D (viscosidad aparente, módulo elástico, módulo viscoso y su variación con la velocidad de cizalla y con el tiempo) y se llevó a cabo dicho estudio reológico en diferentes mezclas porcelánicas, variando factores como la proporción de agua y el tiempo de reposo. De cara a mejorar la viabilidad de las porcelanas para la impresión 3D, se modificaron las propiedades del fluido soporte, mezclando el agua con diferentes compuestos: silicato sódico, un conocido agente tixotrópico (fluidificante), nanotubos de carbono y etanol. Los resultados del estudio realizado sobre la porcelana y los agentes que le introdujeron fueron testados en una impresora 3D con sistema de extrusión, corroborando el efecto positivo del silicato sódico en la mezcla y el efecto óptimo del etanol, que resultó ser el previsiblemente más adecuado.[Abstract]: Nowadays, 3D printing is a very useful system to produce new forms and structures, which is used with broad applications, such as industrial manufacture, biomedicine, engineering and even art. The importance of being able to print different materials is motivating the investigation and development of diverse composites and multicomponent inks. In this Master’s Final Project we describe the study realized to design ceramic materials and its rheological study to analyze its viability in 3D printing. The subject of study of this MFP were two commercial porcelanic clays, which were characterized by powder X Ray Diffraction (XRD), Thermogravimetric Analysis (TGA), Infrared Spectroscopy (IR), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM). We designed a rheological study of porcelain suspensions in water which let us know the physical properties more implicated in the 3D printing process (apparent viscosity, elastic modulus, viscous modulus and its variation with the shear rate and the time) and we applied this rheological study in different porcelanic mixtures, varying factors like the water proportion and the ageing time of the mixtures. The properties of the porcelain suspensions were modified in order to improve its performance at 3D printing by mixing the water with different additives: sodium silicate, a known thixotropic (fluidizing) agent, carbon nanotubes and ethanol. The results of the study we applied to the porcelain and the introduced additives were tested in a 3D printer with extrusion system, corroborating the positive effect of the sodium silicate in the mixture and the optimal effect of the ethanol, which was the predictably more suitable.Traballo fin de mestrado (UDC.CIE). Investigación química y química industrial. Curso 2017/201

Simple and Low-Cost Footstep Energy-Recover Barocaloric Heating and Cooling Device

[Abstract] In this work, we design, build, and test one of the very first barocaloric devices. The here presented device can recover the energy generated by an individual’s footstep and transform it into barocaloric heating and/or cooling. Accordingly, we present an innovative device that can provide eco-friendly and gas-free heating/cooling. Moreover, we test the device by measuring a new barocaloric organic polymer that exhibits a large adiabatic temperature change of ~2.9 K under the application of 380 bar. These results pave the way towards novel and more advanced barocaloric technologies and provide a simple and low-cost device to explore new barocaloric materials.This research was funded by Ministerio de Economía y Competitividad MINECO and EU-FEDER (project MAT2017-86453-R), and Xunta de Galici

Discovery of Colossal Breathing-Caloric Effect under Low Applied Pressure in the Hybrid Organic–Inorganic MIL-53(Al) Material

Financiado para publicación en acceso aberto: Universidade da Coruña/CISUG[Abstract] In this work, “breathing-caloric” effect is introduced as a new term to define very large thermal changes that arise from the combination of structural changes and gas adsorption processes occurring during breathing transitions. In regard to cooling and heating applications, this innovative caloric effect appears under very low working pressures and in a wide operating temperature range. This phenomenon, whose origin is analyzed in depth, is observed and reported here for the first time in the porous hybrid organic–inorganic MIL-53(Al) material. This MOF compound exhibits colossal thermal changes of ΔS ∼ 311 J K–1 kg–1 and ΔH ∼ 93 kJ kg–1 at room temperature (298 K) and under only 16 bar, pressure which is similar to that of common gas refrigerants at the same operating temperature (for instance, p(CO2) ∼ 64 bar and p(R134a) ∼ 6 bar) and noticeably lower than p > 1000 bar of most solid barocaloric materials. Furthermore, MIL-53(Al) can operate in a very wide temperature range from 333 K down to 254 K, matching the operating requirements of most HVAC systems. Therefore, these findings offer new eco-friendly alternatives to the current refrigeration systems that can be easily adapted to existing technologies and open the door to the innovation of future cooling systems yet to be developed.This work was financially supported by Ministerio de Economía y Competitividad MINECO and EU-FEDER (projects MAT2017-86453-R and PDC2021-121076-I00), Xunta de Galicia and IACOBUS Programme. Funding for open access fee was provided by Universidade da Coruña/CISU

Raman Spectroscopy Studies on the Barocaloric Hybrid Perovskite [(CH₃)₄N][Cd(N₃)₃]

[Abstract] Temperature-dependent Raman scattering and differential scanning calorimetry were applied to the study of the hybrid organic-inorganic azide-perovskite [(CH₃)₄N][Cd(N₃)₃], a compound with multiple structural phase transitions as a function of temperature. A significant entropy variation was observed associated to such phase transitions, |∆S| ~ 62.09 J·kg⁻¹ K⁻¹, together with both a positive high barocaloric (BC) coefficient |δTt/δP| ~ 12.39 K kbar⁻¹ and an inverse barocaloric (BC) coefficient |δTt/δP| ~ −6.52 kbar⁻¹, features that render this compound interesting for barocaloric applications. As for the obtained Raman spectra, they revealed that molecular vibrations associated to the NC₄, N₃⁻ and CH₃ molecular groups exhibit clear anomalies during the phase transitions, which include splits and discontinuity in the phonon wavenumber and lifetime. Furthermore, variation of the TMA⁺ and N₃⁻ modes with temperature revealed that while some modes follow the conventional red shift upon heating, others exhibit an unconventional blue shift, a result which was related to the weakening of the intermolecular interactions between the TMA (tetramethylammonium) cations and the azide ligands and the concomitant strengthening of the intramolecular bondings. Therefore, these studies show that Raman spectroscopy is a powerful tool to gain information about phase transitions, structures and intermolecular interactions between the A-cation and the framework, even in complex hybrid organic-inorganic perovskites with highly disordered phases.Conselho Nacional de Desenvolvimento Científico e Tecnológico (Brasil); 431943/2016-8Fundação de Amparo à Pesquisa e ao Desenvolvimento Científico e Tecnológico do Maranhão (Brasil); COOPI-07771/17Ministerio de Economía y Competitividad; MAT2017-86453-RXunta de Galicia; ED431G/0

Near-Room-Temperature Reversible Giant Barocaloric Effects in [(CH₃)₄N]Mn[N₃]₃ Hybrid Perovskite

[Abstract] We report giant reversible barocaloric effects in [(CH₃)₄N]Mn[N₃]₃ hybrid organic–inorganic perovskite, near its first-order cubic-monoclinic structural phase transition at ₀ ∼ 305 K. When driving the transition thermally at atmospheric pressure, the transition displays a large change in entropy of ∼80 J K⁻¹ kg⁻¹ and a small thermal hysteresis of ∼7 K, as well as a large change in volume of ∼1.5%. When driving the transition with pressure near room temperature, the transition displays large changes in entropy of ∼70 J K⁻¹ kg⁻¹, which represent a giant barocaloric response. Hybrid perovskites with similar barocaloric response and lower operating temperatures may find applications in environmentally friendly cooling.The authors are grateful for financial support from Ministerio de Economía y Competitividad MINECO and EU-FEDER (MAT2017-86453-R), Xunta de Galicia (ED431G/09), FAMEPA (COOPI-07771/17), and ERC Starting Grant no. 680032Xunta de Galicia; ED431G/0

((R)-( )-3-Hydroxyquinuclidium)[FeCl4]; a plastic hybrid compound with chirality, ferroelectricity and long range magnetic ordering

Quinuclidinium salts and their derivatives are now in the focus of materials science as building units of multifunctional materials. Their properties can be easily switchable, allowing their use in a wide range of physical applications. One type of these kinds of materials, the homochiral hybrid halometallate ferroelectric compounds, is not well understood. In this work, (R)-( )-3-quinuclidinol hydrochloride was used in the synthesis of ((R)-( )-3-hydroxyquinuclidium)[FeCl4]. The use of this enantiomeric cation forces crystallographic non-centrosymmetry, which was confirmed by polarimetry and circular dichroism spectroscopy. We studied the physical properties of this compound at different temperatures by single crystal, synchrotron and neutron powder X-ray diffraction, which showed a rich series of structural and magnetic phase transitions. From synchrotron powder X-ray diffraction data, a plastic phase was observed above 370 K (phase I). Between 370 K and ca. 310 K, an intermediate polar phase was detected, solved in a non-centrosymmetric polar space group (C2) (phase II). Below ca. 310 K, the compound crystallizes in the triclinic P1 non-centrosymmetric space group (phase III) which is maintained down to 4 K, followed by phase IV, which shows tridimensional magnetic ordering. The temperature evolution of the neutron diffraction data shows the appearance of new reflections below 4 K. These reflections can be indexed to a commensurate propagation vector k = (0, 0, 12). The magnetic structure below TN was solved in the Ps1 Shubnikov space group, which gives rise to an antiferromagnetic structure, compatible with the magnetometry measurements. Near room temperature, the crystal phase transition is associated with a dielectric change. In particular, the phase transition between phase III (S.G.:P1) and phase II (S.G.:C2) involves an increase of symmetry between two non-centrosymmetric space groups. Therefore, it allows, by symmetry, the emergence of ferroelectric and ferroelastic ordering. Piezoresponse force microscopy (PFM) imaging measurements provided evidence for polarization switching and a local ferroelectric behavior of phase III at room temperature. Additionally, the obtained butterfly curve and hysteresis loop by PFM exhibits a low coercive voltage of B10 V. This value is remarkable, since it approaches those obtained for materials with application in ferroelectric random access memories (FeRAMs).Financial support from Universidad de Cantabria (Proyecto Puente convocatoria 2018 funded by SODERCAN_FEDER), Universidad del País Vasco/Euskal Herriko Unibertsitatea (GIU17/50 and PPG17/37) and Ministerio de Economia y Competividad (MAT2017-89239-C2-(1,2)-P, MAT2017-83631-C3-3-R, MAT2017-86453-R, PGC2018-097520-A-100 and PID2019-104050RAI00) is acknowledged. The authors gratefully acknowledge the technical and human support provided by SGIKer (UPV/EHU, MINECO, GV/EJ, ERDF, and ESF). Carmen Martín is grateful to VI PPIT-2018 from Universidad de Sevilla. The paper is (partly) based on the results of experiments carried out at the ALBA Synchrotron Light Source in Barcelona (proposal 2019083666) and Institute Laue-Langevin (ILL) of Grenoble (Proposals 5-31-2580 and 5-31-2460)

Hybrid Organic-inorganic Materials with Phase Transitions for Solid-state Cooling and Solar Thermal Energy Storage

Programa Oficial de Doutoramento en Química Ambiental e Fundamental. 5031V01[Resumo] A presente tese de doutoramento céntrase no estudo de materiais híbridos orgánicos-inorgánicos con transicións de fase para aplicacións de refrixeración en estado sólido e almacenamento de enerxía. Dada a importancia de substituír os compostos perigosos, tóxicos e/ou contaminantes empregados en ditas aplicacións, este traballo céntrase na selección, deseño e síntese de materiais con unidades orgánicas e inorgánicas que poidan proporcionar transicións de fase altamente enerxéticas e outras propiedades funcionais, fundamentais para sistemas enerxéticos como a refrixeración en estado sólido e o almacenamento de enerxía. Estudouse a estrutura química e as propiedades funcionais (calóricas, eléctricas e magnéticas) para analizar o comportamento dos materiais e contemplar opcións innovadoras dada a multi-sensibilidade a diferentes estímulos (temperatura, presión ou campo eléctrico). Como resultado desta investigación, a perovskita híbrida [(CH3)4N]Mn(N3)3 e os cristais plásticos híbridos [(CH3)3(CH2Cl)N]FeCl4, [(CH3)3(CH2Cl)N]GaCl4 e [(CH3)3S]FeCl4 reportanse como materiais barocalóricos prometedores para aplicaciós de refrixeración en estado sólido. Ademais, [(CH3)3(CH2Cl)N]GaCl4 e [(CH3)3S]FeCl4, que son materiais novos reportados nesta tese, presentan propiedades calóricas, eléctricas e magnéticas moi interesantes e axeitadas para aplicacións de almacenamento de enerxía térmica solar e a posibilidade de combinalas con almacenamento de enerxía eléctrica para sistemas multi-funcionais. Os resultados aquí presentados son unha aportación para o desenvolvemento de sistemas sostibles e respectuosos co medio ambiente para o uso e almacenamento de enerxía.[Resumen] La presente tesis doctoral se centra en el estudio de materiales híbridos orgánicos-inorgánicos con transiciones de fase para aplicaciones de refrigeración en estado sólido y almacenamiento de energía. Dada la importancia de sustituir los compuestos peligrosos, tóxicos y/o contaminantes empleados en tales aplicaciones, este trabajo se centra en la selección, diseño y síntesis de materiales con unidades orgánicas e inorgánicas que puedan proporcionar transiciones de fase altamente energéticas y otras propiedades funcionales, fundamentales para sistemas energéticos como la refrigeración en estado sólido y el almacenamiento de energía. Se estudió la estructura química y las propiedades funcionales (calóricas, eléctricas y magnéticas) para analizar el comportamiento de los materiales y contemplar opciones innovadoras dada la multi-sensibilidad a diferentes estímulos (temperatura, presión o campo eléctrico). Como resultado de esta investigación, la perovskita híbrida [(CH3)4N]Mn(N3)3 y los cristales plásticos híbridos [(CH3)3(CH2Cl)N]FeCl4, [(CH3)3(CH2Cl)N]GaCl4 y [(CH3)3S]FeCl4 se reportan como materiales barocalóricos prometedores para aplicaciones de refrigeración en estado sólido. Además, [(CH3)3(CH2Cl)N]GaCl4 y [(CH3)3S]FeCl4, que son materiales nuevos reportados en esta tesis, presentan propiedades calóricas, eléctricas y magnéticas muy interesantes y adecuadas para aplicaciones de almacenamiento de energía térmica solar y la posibilidad de combinarlas con almacenamiento de energía eléctrica para sistemas multi-funcionales. Los resultados aquí presentados son una aportación para el desarrollo de sistemas sostenibles y respetuosos con el medio ambiente para el uso y almacenamiento de energía.[Abstract] The present Ph.D. Thesis is focused on the study of hybrid organic-inorganic materials with phase transitions for solid-state cooling and energy storage applications. Given the importance of substituting the dangerous, toxic and/or polluting compounds employed in such applications, this work is centered in the selection, design and synthesis of materials with organic and inorganic units that can provide high-energetic phase transitions and other functional properties, fundamental for energy systems such as solid-state cooling and energy storage. The chemical structure and functional properties (caloric, electric and magnetic) were studied to analyze the performance of the materials and contemplate innovative options given by the multi-sensitivity to different stimuli (temperature, pressure or electric field). As result of this research, the hybrid perovskite [(CH3)4N]Mn(N3)3 and the hybrid plastic crystals [(CH3)3(CH2Cl)N]FeCl4, [(CH3)3(CH2Cl)N]GaCl4 and [(CH3)3S]FeCl4 are reported as promising barocaloric materials for solid-state cooling. Furthermore, [(CH3)3(CH2Cl)N]GaCl4 and [(CH3)3S]FeCl4, which are new materials reported in this thesis, revealed very interesting caloric, electric and magnetic properties suitable for solar thermal energy storage applications and the possibility of combining them with electrical energy storage for multi-functional systems. The results here presented are an input to the development of sustainable and environmentally-friendly systems for the use and storage of energ

Structural, Thermal and Functional Properties of a Hybrid Dicyanamide-Perovskite Solid Solution

In Solid-State Chemistry, a well-known route to obtain new compounds and modulate their properties is the formation of solid solutions, a strategy widely exploited in the case of classical inorganic perovskites but relatively unexplored among emergent hybrid organic–inorganic perovskites (HOIPs). In this work, to the best of our knowledge, we present the first dicyanamide-perovskite solid solution of [TPrA][Co0.5Ni0.5(dca)3] and study its thermal, dielectric and optical properties, comparing them with those of the parent undoped compounds [TPrA][Co(dca)3] and [TPrA][Ni(dca)3]. In addition, we show that the prepared doped compound can be used as a precursor that, by calcination, allows CNTs with embedded magnetic Ni:Co alloy nanoparticles to be obtained through a fast and much simpler synthetic route than other complex CVD or arc-discharge methods used to obtain this type of material

Structural, Thermal and Functional Properties of a Hybrid Dicyanamide-Perovskite Solid Solution

In Solid-State Chemistry, a well-known route to obtain new compounds and modulate their properties is the formation of solid solutions, a strategy widely exploited in the case of classical inorganic perovskites but relatively unexplored among emergent hybrid organic–inorganic perovskites (HOIPs). In this work, to the best of our knowledge, we present the first dicyanamide-perovskite solid solution of [TPrA][Co0.5Ni0.5(dca)3] and study its thermal, dielectric and optical properties, comparing them with those of the parent undoped compounds [TPrA][Co(dca)3] and [TPrA][Ni(dca)3]. In addition, we show that the prepared doped compound can be used as a precursor that, by calcination, allows CNTs with embedded magnetic Ni:Co alloy nanoparticles to be obtained through a fast and much simpler synthetic route than other complex CVD or arc-discharge methods used to obtain this type of material