Atualmente com o advento da nanociência e nanotecnologia, as nanopartículas magnéticas têm encontrado inúmeras aplicações nos campos da biomedicina, diagnóstico, biologia molecular, bioquímica, catálise, etc. As nanopartículas magnéticas funcionalizadas são constituídas de um núcleo magnético, envolvido por uma camada polimérica com sítios ativos, que podem ancorar metais ou compostos orgânicos seletivos. Estas nanopartículas são consideradas materiais híbridos orgânico-inorgânicos de grande interesse em aplicações comerciais devido à particularidade das propriedades obtidas. Entre as aplicações importantes podemos citar: tratamento por magnetohipertermia, carregadores de fármacos para áreas específicas do corpo, seleção de moléculas específicas, biossensores, melhoria da qualidade de imagens por RMN, etc. O trabalho foi desenvolvido em duas partes: 1) a síntese do núcleo constituído de nanopartículas superparamagnéticas de ferrita de cobalto e, 2) o recobrimento do núcleo por um polímero bifuncional o 3-aminopropiltrietoxissilano. Os parâmetros estudados na primeira parte da pesquisa foram: pH, concentração molar da base, tipo de base, ordem de adição dos reagentes, modo de adição dos reagentes, velocidade de agitação, concentração inicial dos metais, fração molar de cobalto e tratamento térmico. Na segunda parte estudou-se: o pH, a temperatura, o catalisador, a concentração do catalisador, o tempo de reação, a relação H2O/silano, o tipo de meio, o agente umectante e a eficiência do recobrimento em relação ao pH. Os produtos obtidos foram caracterizados pelas técnicas de difratometria de raios-X (DRX), microscopia eletrônica de transmissão (MET), microscopia eletrônica de varredura (MEV), espectroscopia de energia dispersiva (EDS), espectroscopia de emissão atômica (ICP-AES), espectroscopia por infravermelho (FTIR), análises termogravimétricas (TGA/DTGA), calorimetria exploratória diferencial (DSC) e curvas de magnetização (MAV) / Nowadays with the appear of nanoscience and nanotechnology, magnetic nanoparticles have been finding a variety of applications in the fields of biomedicine, diagnosis, molecular biology, biochemistry, catalysis, etc. The magnetic functionalized nanoparticles are constituted of a magnetic nucleus, involved by a polymeric layer with active sites, which ones could anchor metals or selective organic compounds. These nanoparticles are considered organic-inorganic hybrid materials and have great interest as materials for commercial applications due to the specific properties. Among the important applications it can be mentioned: magnetohyperthermia treatment, drugs delivery in specific local of the body, molecular recognition, biossensors, enhancement of nuclear magnetic ressonance images quality, etc. This work was developed in two parts: 1) the synthesis of the nucleus composed by superparamagnetic nanoparticles of cobalt ferrite and, 2) the recovering of nucleus by a polymeric bifunctional 3-aminepropyltriethoxysilane. The parameters studied in the first part of the research were: pH, hydroxide molar concentration, hydroxide type, reagent order of addition, reagent way of addition, speed of shake, metals initial concentrations, molar fraction of cobalt and thermal treatment. In the second part it was studied: pH, temperature, catalyst type, catalyst concentration, time of reaction, relation ratios of H2O/silane, type of medium and the efficiency of the recovering regarding to pH. The products obtained were characterized using the following techniques X-ray powder diffraction (DRX), transmission electronic microscopy (MET), scanning electronic microscopy (MEV), spectroscopy of scatterbrained energy spectroscopy (DES), atomic emission spectroscopy (ICP-AES), themogravimetric analysis (TGA/DTGA), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and magnetization curves (VSM)

Atualmente com o advento da nanociência e nanotecnologia, as nanopartículas magnéticas têm encontrado inúmeras aplicações nos campos da biomedicina, diagnóstico, biologia molecular, bioquímica, catálise, etc. As nanopartículas magnéticas funcionalizadas são constituídas de um núcleo magnético, envolvido por uma camada polimérica com sítios ativos, que podem ancorar metais ou compostos orgânicos seletivos. Estas nanopartículas são consideradas materiais híbridos orgânico-inorgânicos de grande interesse em aplicações comerciais devido à particularidade das propriedades obtidas. Entre as aplicações importantes podemos citar: tratamento por magnetohipertermia, carregadores de fármacos para áreas específicas do corpo, seleção de moléculas específicas, biossensores, melhoria da qualidade de imagens por RMN, etc. O trabalho foi desenvolvido em duas partes: 1) a síntese do núcleo constituído de nanopartículas superparamagnéticas de ferrita de cobalto e, 2) o recobrimento do núcleo por um polímero bifuncional o 3-aminopropiltrietoxissilano. Os parâmetros estudados na primeira parte da pesquisa foram: pH, concentração molar da base, tipo de base, ordem de adição dos reagentes, modo de adição dos reagentes, velocidade de agitação, concentração inicial dos metais, fração molar de cobalto e tratamento térmico. Na segunda parte estudou-se: o pH, a temperatura, o catalisador, a concentração do catalisador, o tempo de reação, a relação H2O/silano, o tipo de meio, o agente umectante e a eficiência do recobrimento em relação ao pH. Os produtos obtidos foram caracterizados pelas técnicas de difratometria de raios-X (DRX), microscopia eletrônica de transmissão (MET), microscopia eletrônica de varredura (MEV), espectroscopia de energia dispersiva (EDS), espectroscopia de emissão atômica (ICP-AES), espectroscopia por infravermelho (FTIR), análises termogravimétricas (TGA/DTGA), calorimetria exploratória diferencial (DSC) e curvas de magnetização (MAV) / Nowadays with the appear of nanoscience and nanotechnology, magnetic nanoparticles have been finding a variety of applications in the fields of biomedicine, diagnosis, molecular biology, biochemistry, catalysis, etc. The magnetic functionalized nanoparticles are constituted of a magnetic nucleus, involved by a polymeric layer with active sites, which ones could anchor metals or selective organic compounds. These nanoparticles are considered organic-inorganic hybrid materials and have great interest as materials for commercial applications due to the specific properties. Among the important applications it can be mentioned: magnetohyperthermia treatment, drugs delivery in specific local of the body, molecular recognition, biossensors, enhancement of nuclear magnetic ressonance images quality, etc. This work was developed in two parts: 1) the synthesis of the nucleus composed by superparamagnetic nanoparticles of cobalt ferrite and, 2) the recovering of nucleus by a polymeric bifunctional 3-aminepropyltriethoxysilane. The parameters studied in the first part of the research were: pH, hydroxide molar concentration, hydroxide type, reagent order of addition, reagent way of addition, speed of shake, metals initial concentrations, molar fraction of cobalt and thermal treatment. In the second part it was studied: pH, temperature, catalyst type, catalyst concentration, time of reaction, relation ratios of H2O/silane, type of medium and the efficiency of the recovering regarding to pH. The products obtained were characterized using the following techniques X-ray powder diffraction (DRX), transmission electronic microscopy (MET), scanning electronic microscopy (MEV), spectroscopy of scatterbrained energy spectroscopy (DES), atomic emission spectroscopy (ICP-AES), themogravimetric analysis (TGA/DTGA), Fourier transform infrared spectroscopy (FTIR), differential scanning calorimetry (DSC) and magnetization curves (VSM)

Efterfrågan på bättre och mer hållbart material ökar. Mer effektivt material kommer att behövas för att möta den ökande, globala efterfrågan. Hybrida organiska-oorganiska material är en typ av material som har varit av stort intresse nyligen, och kan beskrivas som en typ av material som består av både organiska och oorganiska komponenter. Denna avhandling har fokuserat på hybrida organiska-oorganiska material inspirerade av den klassiska perovskitstrukturen ABX3, där komponent A är en organisk katjon, komponent B är en divalent metalkatjon och komponent X är en anjon. Hybrida organiska-oorganiska material som är utgår från den klassiska perovskitstrukturen kan ha olika funktionella egenskaper och en bred variation av tänkbara applikationer. Några exempel på dessa egenskaper och möjliga applikationer inkluderar god fotokonduktivitet för solceller, utmärkt emissionsegenskaper för ljusdioder och justerbara dielektriska egenskaper för elektroniska växlar och sensorer.  De fysiska egenskaperna av det hybrida organiska-oorganiska materialet beror på kristallstrukturen av materialet, som i sig bestäms av valet av komponenter. På grund av de många möjligheter av organiska och oorganiska komponenter så finns det möjlighet att syntetisera helt nya hybrida organiska-oorganiska föreningar som kan ha nya eller förbättrade fysiska egenskaper.  Nuvarande hybrida organiska-oorganiska material som utgår från perovskitstrukturen använder huvudsakligen bly som divalent metalkatjon, och det beror på att den ger den bästa funktionella effekten. Blys toxicitet är dock en stor nackdel för nuvarande blybaserade hybrid oorganiska material. Möjligheten att ersätta bly med en annan divalent metall har undersökts under detta projekt. I denna avhandling så har den organiska katjonen cyclohexylammonium (CHA) varit i fokus som den organiska komponenten. Målet med detta examensarbete var att designa, syntetisera och karakterisera nytt hybrid organisk-oorganiskt material. De hybrida organiska-oorganiska föreningarna CHAZnBr3 och (CHA)2ZnBr4 syntetiserades för den första gången, så vitt författaren vet, och kommer vara i fokus i denna avhandling. De två nya hybrida organiska-oorganiska föreningarna blev strukturellt karakteriserade med X-ray Diffraction (XRD) och termiskt karakteriserade med Thermal Gravimetric Analysis (TGA) och Differential Scanning Calorimetry (DSC).  Den första föreningen, CHAZnBr3, kunde bestämmas att vara ortorombisk vid 298 K. Föreningen bestämdes vara termisk stabil upp till 490 K, och genomgår en fasövergång vid 445 K. Den andra föreningen, (CHA)2ZnBr4, kunde inte bestämmas strukturellt vid varken 100 K eller 298 K. Föreningen bestämdes vara termisk stabil upp till 490 K, och genomgår en fasövergång vid 230 K. Ytterligare karakterisering krävs för att bättre förstå egenskaperna hos dessa föreningar och deras möjliga användningsområden. / The demand for better and more sustainable material is increasing. More efficient materials will be needed to meet the growing global need. Hybrid organic-inorganic materials are one type of materials that have been of great interest recently, which can be described as a class of materials that mix organic and inorganic components. This thesis focused on hybrid organic-inorganic materials inspired by the classical perovskite crystal structure ABX3, where component A is an organic cation, component B is a divalent metal cation and component X is an anion. Hybrid organic-inorganic materials based on the classical perovskite structure may have various functional properties and may have a broad range of potential applications. Some examples of those properties as well as some and possible applications include good photoconductivity and power conversion efficiency for photovoltaic devices, excellent emission properties for light emitting diodes and tunable dielectric properties for electronic switches and sensors.  The physical properties of the hybrid organic-inorganic material are determined by the crystal structure of the material, which in turn will be decided by the choice of components. With the many possible choices for organic and inorganic components, there is an opportunity to synthesize completely new hybrid organic-inorganic compounds that may display new or superior physical properties. Current hybrid organic-inorganic materials based on the perovskite crystal structure mainly use lead as the divalent metal, since it currently gives the best performance. The toxicity of lead is a major drawback for current lead-based hybrid organic-inorganic materials. The possibility to replace lead with another divalent metal has been explored during this project. For this thesis, the organic cation cyclohexylammonium (CHA) has been of focus as the organic component. The aim of this thesis was to design, synthesize and characterize novel hybrid organic-inorganic compounds. The hybrid organic-inorganic compounds CHAZnBr3 and (CHA)2ZnBr4 were synthesized for the first time, to the best of our knowledge, and will be the focus of this thesis. The two new hybrid organic-inorganic compounds were structurally characterized by X-ray Diffraction (XRD) and thermally characterized by Thermal Gravimetric Analysis (TGA) and Differential Scanning Calorimetry (DSC).  The first compound, CHAZnBr3, could be determined to be orthorhombic at 298 K. The compound was found to be thermally stable up 490 K, and to undergo a phase transition at 445 K.  The second compound, (CHA)2ZnBr4, could not be fully structurally solved at either 100 K or 298 K. The compound was found to be thermally stable up to 490 K, and to undergo a phase transition at 230 K.  Further characterization will be needed to better understand the properties of these two compounds and their possible applications.