A Polianilina (PANI) e os polímeros derivados da anilina têm recebido grande atenção devido às suas aplicações tecnológicas. A introdução de grupos funcionais polares e de grupos alquila à cadeia principal da PANI é um artifício para se obter polímeros solúveis em uma maior variedade de solventes orgânicos. A Poli(o-metoxianilina) (POMA) é um dos derivados da PANI e sua diferença estrutural está na presença do grupo (-OCH3) na posição orto dos anéis de carbono, sendo bastante estudada na forma de pó ou de filmes para as mais diversas aplicações. Apesar do grande número de trabalhos realizados com a PANI e seus derivados, são poucos os que focam um estudo estrutural desses materiais nas formas dopada (ES) e desdopada (EB). PANI e POMA foram sintetizadas quimicamente utilizando-se 0,5 e 1,0M \'H\'CL\' e tempos de síntese compreendidos entre 0,5 e 96 h. As amostras foram caracterizadas por XRD, SAXS e SEM. Através dos dados de XRD, utilizou-se o ajuste LeBail para obter informações microestruturais através do programa FULLPROF. A análise de XRD mostrou que o tempo de síntese não interferiu significativamente na cristalinidade da PANI, porém, é um parâmetro importante na síntese da POMA, a qual se tornou mais cristalina. Através do SAXS foi possível obter os valores dos raios de giro (Rg) e a dimensão máxima das partículas (Dmáx) a partir da função de distribuição de distâncias entre pares (p(r)) e, através das curvas de Kratky, foi possível analisar qualitativamente a organização das partículas. Através do ajuste LeBail foi possível verificar que o tamanho médio dos cristalitos da PANI-ES e PANI-EB são, respectivamente, 34 e 27 Å. Para a POMA-ES, os cristalitos aumentam com o aumento do tempo de síntese, ficando num intervalo de 26 - 57 Å, enquanto a POMA-EB apresentou cristalitos com 19 Å. As imagens de SEM permitiram a visualização de diferentes morfologias para PANI e POMA: enquanto a PANI-ES apresentou morfologia de fibras formadas por nanoesferas interligadas, a POMA-ES apresentou morfologia globular vesicular, a qual sofreu mudanças significativas com o aumento do tempo de síntese. As morfologias da PANI-EB e POMA-EB mostraram-se bastante diferentes daquelas observadas em suas respectivas formas dopadas. As medidas de condutividade não foram alteradas drasticamente para a PANI, enquanto que para a POMA, a condutividade aumentou durante a síntese. Analisar coerentemente os resultados obtidos através de cada uma das técnicas utilizadas e compreender um pouco mais a estrutura dos materiais poliméricos é essencial para relatar suas propriedades e contribuir com informações para esta misteriosa classe de materiais. / Polyaniline (PANI) and derivatives of aniline have received great attention due to their technological applications. The introduction of polar functional groups and alkyl groups to the main chain of PANI is a practice to obtain soluble polymers in a wider variety of organic solvents. Poly (o-methoxyaniline) (POMA) is a derivative of PANI and its structural difference is the presence of the group (-OCH3) in the ortho position of the carbon rings, been extensively studied in the form of powder or films for the most various applications. Despite the large number of studies performed with PANI and its derivatives, there are few that focus on a structural study of these materials in doped (ES) and undoped (EB) forms. PANI and POMA were chemically synthesized using 0.5 and 1.0 M \'H\'CL\' and synthesis times between 0.5 and 96 h. The samples were characterized by XRD, SAXS and SEM. XRD analysis showed that the synthesis time was not significant in the crystallinity of PANI, however, is an important parameter in the synthesis of POMA, which became more crystalline. Through the data of XRD, we applied the LeBail Fit using the program FullProf, showing that the average size of crystallites of PANI-ES and PANI-EB are respectively 34 and 27 Å. As for the POMA-ES, the crystallites increases with increasing synthesis time, staying in a range from 26 to 57 Å, while the POMA-EB showed crystallites with 19 Å. By SAXS was possible to obtain values of Radius of Giration (Rg) and the maximum particle size (Dmax) from the Pair-distance distribution Function (p(r)) and, through the Kratky curves, was possible to qualitatively analyze the particles organization. The images of SEM allowed the visualization of different morphologies for PANI and POMA: while the PANI-ES showed fibers morphology formed by interconnected nanospheres, the POMA-ES had a globular vesicular morphology, which changed with increasing synthesis time. Morphologies of PANI-EB and POMA-EB were quite different from those observed in their doped forms. The conductivity measurements were not changed drastically for the PANI, whereas for the POMA, the conductivity increased during the synthesis. Consistently analyze the results obtained by each of the techniques and understand the structure of polymeric materials is essential to relate their properties and contribute to this mysterious class of materials.

The elemental composition of the samples of modern and archaeological ceramics was determined using the energy dispersive X-ray analysis, flame atomic absorption spectrometry, titrimetric and spectrophotometric analysis methods. It has been shown that the qualitative and quantitative composition of all the samples is different. It has been established that silicon and aluminium are the main elements in all the samples. SiO2 accounts for 46–60 % of the composition of the ceramics, Al2O3 – for some 17–33%. The amounts of Fe, Na, Mg, K, Ca and Ti discovered in the samples are several times lesser. EDX analysis can successfully be used in determining the main elements whose amounts exceed 0.5% of the overall elemental composition. In order to determine the exact composition of ceramics one has to employ the FAAS analysis method. To determine in a credible manner the amount of aluminium in ceramics, one can use the titrimetric method, and the amount of silicon and titanium – spectrophotometric methods. Upon examination of the modern and archaeological ceramics by diffraction analysis it has been established that the main phase of all the samples is the same – quartz SiO2, however their phase composition varies. In different samples the following phases have been discovered: calcite, dolomite, kaolinite, albite, microcline, muscovite, mullite, hematite, rutile, diopside, corundum, titanite, and sodium anorthite. Being aware of the phase composition, it has been established that the... [to full text] / Šioje daktaro disertacijoje pirmoje dalyje nustatyta šiuolaikinės, o antroje dalyje – archeologinės keramikos gaminių elementinė ir fazinė sudėtis, bei ištirta morfologija. Šiuolaikinės ir archeologinės keramikos pavyzdžių elementinė sudėtis nustatyta Rentgeno spindulių dispersinės analizės (EDX), liepsnos atominės absorbcinės spektrometrijos (LAAS), titrimetrinės ir spektrofotometrinės analizės metodais. Parodyta, kad visų keraminių pavyzdžių kokybinė bei kiekybinė sudėtis yra skirtinga Nustatyta, kad visuose keramikos mėginiuose pagrindiniai elementai yra silicis ir aliuminis. SiO2 sudaro 46 – 60% keramikos sudėties, Al2O3 – apie 17 – 33%. Fe, Na, Mg, K, Ca ir Ti mėginiuose rasta kelis kartus mažiau. EDX analizė gali būti sėkmingai naudojama nustatant pagrindinius elementus, kurių kiekiai viršija 0,5 % bendros elementinės sudėties. Norint nustatyti tikslią keramikos sudėtį ir pėdsakinius elementus reikia naudoti LAAS analizės metodą. Aliuminio kiekį keramikoje patikimai galima nustatyti titrimetriniu, o silicio ir titano kiekį – spektrofotometriniais metodais. Ištyrus šiuolaikę ir archeologinę keramiką Rentgeno spindulių difrakcine analize (XRD), nustatyta, kad visų keramikų pagrindinė fazė yra vienoda – silicio dioksidas SiO2, tačiau jų bendra fazinė sudėtis skiriasi. Skirtinguose kermikos pavyzdžiuose buvo aptikos šios fazės: kvarcas, dolomitas, kaolinas, albitas, mikroklinas, muskovitas, mulitas, hematitas, rutilas, diopsidas, korundas, titanitas, natrio anortitas... [toliau žr. visą tekstą]

In this dissertation, the results of detailed investigation of the seven unique art objects are presented. The presented results show that complex apllying of the instrumental analytical methods of OM, FTIR, SEM/EDX, XRD, μXRD and µRS is accurate and efficient way to identify composition of works of art and archaeological finds of glass, pigments or describe their technology. IR spectroscopy has been successfully applied to determine pigments and some pigment mixtures in painting‘s ground, paint layers, and destruction products in archaeological glass. The SEM/EDX analysis successfully can be used in determining the main elements of the paint samples at different cross-section points perform a qualitative analysis of the pigments (cinnabar, lead white, chalk, smalt et. al. ), in some cases, to discuss the features of the production of pigments. The SEM/EDX provided a possibility to examine three archaeological glass beads. According to the elemental composition, microstructure, and the specific features in different areas of the glass was defined nature of the destruction of glass. XRD and μXRD analysis successfully can be used in determining the crystalline phases in the paint and archaeological glass samples. Identify following pigments and their mixtures: calcite CaCO3, carbon, lead tin yellow type I Pb2SnO4, lead tin yellow type II PbSn03, hydrocerussite 2PbCO3 ∙ Pb (OH)2, cerussite PbCO3, Egyptian blue CaCuSi4O10, gypsum CaSO4 ∙ 2H2O, anhydrite CaSO4, huntite Mg3Ca(CO3)4... [to full text] / Septynių unikalių, didelę istorinę ir meninę vertę turinčių objektų – trijų XVII ir XVIII a. paveikslų, Senovės Egipto sarkofago bei trijų archeologinių stiklo karolių iš Kernavės-Kriveikiškių kapinyno – tyrimams sėkmingai pritaikyti OM, FTIR, SEM/EDX, XRD, μXRD ir µRS analizės metodai. Konstatuota, kad taikant kompleksinius tyrimus galima tiksliai ir efektyviai identifikuoti kūrinių medžiagas, charakterizuoti jų sandarą, apibūdinti technologijas. IR spektroskopija sėkmingai panaudota identifikuojant tapybos grunto ir dažų sluoksnių neorganinius tapybos pigmentus ir jų mišinius bei stiklo korozijos produktus. Parodyta, kad IR spektroskopija gali būti sėkmingai panaudota identifikuojant istorines restauravimo medžiagas. SEM/EDX analizės metodu nustatyta tapybos elementinė sudėtis, identifikuoti cinoberio, švino baltojo, kreidos, smaltos, suriko ir kt. pigmentai. SEM/EDX analizės metodu ištirti trys archeologiniai stiklo karoliai. Pagal elementinės sudėties skirtumus ir specifinius mikrostruktūros bruožus nustatytas stiklo destrukcijos pobūdis. XRD ir μXRD analizės metodais sėkmingai identifikuoti šie pigmentai ir/ar jų mišiniai: kalcitas CaCO3, anglis, I tipo Pb–Sn geltonasis Pb2SnO4, II tipo Pb–Sn geltonasis PbSn03, hidrocerusitas 2PbCO3∙Pb(OH)2, cerusitas PbCO3, Egipto mėlynasis CaCuSi4O10, gipsas CaSO4∙2H2O, anhidritas CaSO4, huntitas Mg3Ca(CO3)4, dolomitas CaMg(CO3)2. Pirmą kartą μRS metodu identifikuotas II tipo švino alavo geltonasis pigmentas, archeologiniam stiklui... [toliau žr. visą tekstą]

Septynių unikalių, didelę istorinę ir meninę vertę turinčių objektų – trijų XVII ir XVIII a. paveikslų, Senovės Egipto sarkofago bei trijų archeologinių stiklo karolių iš Kernavės-Kriveikiškių kapinyno – tyrimams sėkmingai pritaikyti OM, FTIR, SEM/EDX, XRD, μXRD ir µRS analizės metodai. Konstatuota, kad taikant kompleksinius tyrimus galima tiksliai ir efektyviai identifikuoti kūrinių medžiagas, charakterizuoti jų sandarą, apibūdinti technologijas. IR spektroskopija sėkmingai panaudota identifikuojant tapybos grunto ir dažų sluoksnių neorganinius tapybos pigmentus ir jų mišinius bei stiklo korozijos produktus. Parodyta, kad IR spektroskopija gali būti sėkmingai panaudota identifikuojant istorines restauravimo medžiagas. SEM/EDX analizės metodu nustatyta tapybos elementinė sudėtis, identifikuoti cinoberio, švino baltojo, kreidos, smaltos, suriko ir kt. pigmentai. SEM/EDX analizės metodu ištirti trys archeologiniai stiklo karoliai. Pagal elementinės sudėties skirtumus ir specifinius mikrostruktūros bruožus nustatytas stiklo destrukcijos pobūdis. XRD ir μXRD analizės metodais sėkmingai identifikuoti šie pigmentai ir/ar jų mišiniai: kalcitas CaCO3, anglis, I tipo Pb–Sn geltonasis Pb2SnO4, II tipo Pb–Sn geltonasis PbSn03, hidrocerusitas 2PbCO3∙Pb(OH)2, cerusitas PbCO3, Egipto mėlynasis CaCuSi4O10, gipsas CaSO4∙2H2O, anhidritas CaSO4, huntitas Mg3Ca(CO3)4, dolomitas CaMg(CO3)2. Pirmą kartą μRS metodu identifikuotas II tipo švino alavo geltonasis pigmentas, archeologiniam stiklui... [toliau žr. visą tekstą] / In this dissertation, the results of detailed investigation of the seven unique art objects are presented. The presented results show that complex apllying of the instrumental analytical methods of OM, FTIR, SEM/EDX, XRD, μXRD and µRS is accurate and efficient way to identify composition of works of art and archaeological finds of glass, pigments or describe their technology. IR spectroscopy has been successfully applied to determine pigments and some pigment mixtures in painting‘s ground, paint layers, and destruction products in archaeological glass. The SEM/EDX analysis successfully can be used in determining the main elements of the paint samples at different cross-section points perform a qualitative analysis of the pigments (cinnabar, lead white, chalk, smalt et. al. ), in some cases, to discuss the features of the production of pigments. The SEM/EDX provided a possibility to examine three archaeological glass beads. According to the elemental composition, microstructure, and the specific features in different areas of the glass was defined nature of the destruction of glass. XRD and μXRD analysis successfully can be used in determining the crystalline phases in the paint and archaeological glass samples. Identify following pigments and their mixtures: calcite CaCO3, carbon, lead tin yellow type I Pb2SnO4, lead tin yellow type II PbSn03, hydrocerussite 2PbCO3 ∙ Pb (OH)2, cerussite PbCO3, Egyptian blue CaCuSi4O10, gypsum CaSO4 ∙ 2H2O, anhydrite CaSO4, huntite Mg... [to full text]

Varias técnicas de física nuclear tem sido aplicadas no estudo de artefatos arqueológicos e de arte contribuindo para seu restauro e preservação. A aplicação destas técnicas são indicadas por não serem destrutivas, preservando o material a ser analisado. Neste trabalho, propomos um procedimento para a investigação indireta da dureza de espadas antigas, por meio de técnicas não destrutivas. Com este proposito as técnicas PIXE, NRA, XRD e RBS se adequam ao nosso estudo de espadas antigas, especificamente uma espada Indiana (Damascena) e outra Japonesa (Wakizashi). Com a técnica PIXE esperávamos identificar os elementos presentes nas laminas das espadas e em suas empunhaduras. Na espada Indiana os elementos identificados foram: Cr, Mn, Fe, Ni, Cu, Zn e As. Para a espada Japonesa somente o elemento Fe foi identificado, mas com o auxílio da técnica RBS identificamos também, um filme fino de carbono na superfície da lamina, medindo 0; 75 _m de espessura. Nas empunhaduras foram identificados os elementos Cr, Fe, Cu e Au para a espada Indiana; Fe, Cu, As e Ag na peca Habaki e S, Cl, K, CA, Fe, As e Au na peca Fuchi, estas duas pecas fazem parte da empunhadura da espada Japonesa. A técnica XRD foi usada para verificarmos as estruturas cristalinas que se formam na superfície das laminas durante o processo de forja (variação de 6 temperatura e deformações plástica). Estas informações possibilitam inferir sobre a temperatura de forja e consequências da deformação plásticas. A fase cristalina da superfície das laminas foi identificada como ferro na forma cristalina cubica de corpo centrado. Nesta estrutura, ha a formação de pequenos cristais orientados (cristalitos), que apresentaram tamanho médio da ordem de 200 _A. Foi verificado que ha também uma fase amorfa do ferro na espada Japonesa, sugerindo que o processo de forja alcançou temperaturas menores quando comparada com a espada Indiana. A espada Damascena _e muito famosa pela dureza e ductibilidade apresentada por sua lamina. Um elemento que pode contribuir para estas caraterísticas e o nitrogênio, que pode ser identificado usando a técnica NRA, mais especificamente a reação 15N(p; _)12C. O nitrogênio poderia ser introduzido na lamina durante o processo de endurecimento da região de corte. Neste processo a lamina era resfriada em urina animal, composta principalmente por acido úrico (C5H4N4O3) e ureia (NH2)2CO. Não foi possível identificarmos a presença de nitrogênio dentro do nosso limite de detecção (acima de 0; 263(4)% em massa de nitrogênio, valor referenciado para a amostra padrão CRM-298). / A set of physical techniques have been applied to characterize archaeological and art artifacts and contribute to its preservation and restoration. The application of these techniques are indicated because they are non invasive methods, preserving the material to be analyzed. In this work, we propose a procedure to investigate indirectly the hardness of ancient swords, by nondestructive techniques. With this aim, we decided to apply the techniques PIXE, NRA, XRD and RBS in the study of ancient swords, specially Indian (Damascus blade) and a Japanese (Wakizashi) swords. With PIXE we identified the major compounds in the blades and in their grips. In the Indian blade were identified the following elements: Cr, Mn, Fe, Ni, Cu, Zn e As. In the Japanese only iron was identified, although, with RBS we could identified a thin _lm of carbon on its surface. The grips were also analyzed and the results indicated to Indian were: Cr, Fe, Cu and Au; and to Japanese: Fe, Cu, As e Ag in the peace Habaki, and S, Cl, K, CA, Fe, As e Au in the peace Fuchi, those pieces are part of the grip. The XRD technique was applied to verify the crystalline structure which were formed during the forging process (hammering and quenching). These information can help to understand more about the quenching and hammering process. The crystalline phase in the surface of the blade was identified as iron. The surface is composed by crystallites oriented with grain size in order to 200_A, oriented as the result of hammering process. Also there is an amorphous phase in the Japanese blade, suggesting that in the forje process the temperature achieved was lower when compared with the Indian sword. The Damascus blade is famous due its hardness and ductility. An element that can improve these characteristics is the nitrogen. Its determination is possible using NRA technique, more specially the reaction 15N(p; _)12C. The nitrogen could been insert in the blade during the edge hardness process (in this process the blade was quenched into animal urine that its main compound are uric acid (C5H4N4O3) and urea (NH2)2CO, or in a brine). It was not possible to identify the presence of nitrogen within our limit of quantification.

A Polianilina (PANI) e os polímeros derivados da anilina têm recebido grande atenção devido às suas aplicações tecnológicas. A introdução de grupos funcionais polares e de grupos alquila à cadeia principal da PANI é um artifício para se obter polímeros solúveis em uma maior variedade de solventes orgânicos. A Poli(o-metoxianilina) (POMA) é um dos derivados da PANI e sua diferença estrutural está na presença do grupo (-OCH3) na posição orto dos anéis de carbono, sendo bastante estudada na forma de pó ou de filmes para as mais diversas aplicações. Apesar do grande número de trabalhos realizados com a PANI e seus derivados, são poucos os que focam um estudo estrutural desses materiais nas formas dopada (ES) e desdopada (EB). PANI e POMA foram sintetizadas quimicamente utilizando-se 0,5 e 1,0M \'H\'CL\' e tempos de síntese compreendidos entre 0,5 e 96 h. As amostras foram caracterizadas por XRD, SAXS e SEM. Através dos dados de XRD, utilizou-se o ajuste LeBail para obter informações microestruturais através do programa FULLPROF. A análise de XRD mostrou que o tempo de síntese não interferiu significativamente na cristalinidade da PANI, porém, é um parâmetro importante na síntese da POMA, a qual se tornou mais cristalina. Através do SAXS foi possível obter os valores dos raios de giro (Rg) e a dimensão máxima das partículas (Dmáx) a partir da função de distribuição de distâncias entre pares (p(r)) e, através das curvas de Kratky, foi possível analisar qualitativamente a organização das partículas. Através do ajuste LeBail foi possível verificar que o tamanho médio dos cristalitos da PANI-ES e PANI-EB são, respectivamente, 34 e 27 Å. Para a POMA-ES, os cristalitos aumentam com o aumento do tempo de síntese, ficando num intervalo de 26 - 57 Å, enquanto a POMA-EB apresentou cristalitos com 19 Å. As imagens de SEM permitiram a visualização de diferentes morfologias para PANI e POMA: enquanto a PANI-ES apresentou morfologia de fibras formadas por nanoesferas interligadas, a POMA-ES apresentou morfologia globular vesicular, a qual sofreu mudanças significativas com o aumento do tempo de síntese. As morfologias da PANI-EB e POMA-EB mostraram-se bastante diferentes daquelas observadas em suas respectivas formas dopadas. As medidas de condutividade não foram alteradas drasticamente para a PANI, enquanto que para a POMA, a condutividade aumentou durante a síntese. Analisar coerentemente os resultados obtidos através de cada uma das técnicas utilizadas e compreender um pouco mais a estrutura dos materiais poliméricos é essencial para relatar suas propriedades e contribuir com informações para esta misteriosa classe de materiais. / Polyaniline (PANI) and derivatives of aniline have received great attention due to their technological applications. The introduction of polar functional groups and alkyl groups to the main chain of PANI is a practice to obtain soluble polymers in a wider variety of organic solvents. Poly (o-methoxyaniline) (POMA) is a derivative of PANI and its structural difference is the presence of the group (-OCH3) in the ortho position of the carbon rings, been extensively studied in the form of powder or films for the most various applications. Despite the large number of studies performed with PANI and its derivatives, there are few that focus on a structural study of these materials in doped (ES) and undoped (EB) forms. PANI and POMA were chemically synthesized using 0.5 and 1.0 M \'H\'CL\' and synthesis times between 0.5 and 96 h. The samples were characterized by XRD, SAXS and SEM. XRD analysis showed that the synthesis time was not significant in the crystallinity of PANI, however, is an important parameter in the synthesis of POMA, which became more crystalline. Through the data of XRD, we applied the LeBail Fit using the program FullProf, showing that the average size of crystallites of PANI-ES and PANI-EB are respectively 34 and 27 Å. As for the POMA-ES, the crystallites increases with increasing synthesis time, staying in a range from 26 to 57 Å, while the POMA-EB showed crystallites with 19 Å. By SAXS was possible to obtain values of Radius of Giration (Rg) and the maximum particle size (Dmax) from the Pair-distance distribution Function (p(r)) and, through the Kratky curves, was possible to qualitatively analyze the particles organization. The images of SEM allowed the visualization of different morphologies for PANI and POMA: while the PANI-ES showed fibers morphology formed by interconnected nanospheres, the POMA-ES had a globular vesicular morphology, which changed with increasing synthesis time. Morphologies of PANI-EB and POMA-EB were quite different from those observed in their doped forms. The conductivity measurements were not changed drastically for the PANI, whereas for the POMA, the conductivity increased during the synthesis. Consistently analyze the results obtained by each of the techniques and understand the structure of polymeric materials is essential to relate their properties and contribute to this mysterious class of materials.

Presented diploma thesis is dealing with study of exciters of anhydrite binders. Theoretical part is dedicated to study of available domestic and foreign literature on a given topic. Attention is also paid to the study of the current research at the institute of THD. In the experimental part is developed a proposal of potential exciters of hydration on the basis of literature and according to the results of the research at the institute of THD. Next is proposed the methodological concept of the work. Testing of the monitored technological features follows. The study of the hydration process was recorded using XRD analysis and thermal analysis. Evaluation of the results was implemented by the mutual comparing of prepared recipes.

The diploma thesis deals with researching electrodeposition of silicon in anhydrous solutions. As electrolyte was used EC:DMC (1:1) with (C2H5)4NBF4, LiPF6 and LiClO4. Research was measured by cyclic voltammetry and XRD.

In this dissertation, methods to synthesize ZnO are reported. First, zinc oxide nanoparticles were synthesized with small amounts of transition metal ions to create materials called dilute magnetic semiconductors (DMS). We employed a low temperature sol-gel method that produces ZnO nanoparticles of reproducible size and incorporates cobalt, nickel, and manganese ions into the nanoparticles. Conditions were controlled such that a range of amounts of Co, Ni, and Mn were incorporated. The incorporation was tracked by color changes in the white ZnO powder to blue for Co, green for Ni and yellow for Mn. XRD measurements showed the nanoparticles were on the order of 10 nm in diameter and had a wurtzite structure. Magnetic measurements showed a change from diamagnetic to paramagnetic behavior with increasing concentration of metal dopants. Second, formation of ZnO single crystal hexagonal prisms from a sol-gel method is presented. The method required water, zinc acetate, and ethanolamine to create a gel of zinc hydroxide and zinc hydroxide acetate, which upon heating formed single crystal hexagonal prisms. Characterization of the gel was done by XRD as well as XRD high temperature chamber (HTK) to determine the role of temperature in prism formation. SEM images showed hexagonal prisms were of uniform size (0.5 × 2 µm.) TEM and electron diffraction images showed a change from randomly oriented particles to an ordered single crystal after heating. Water and the acetate salt of zinc proved to be critical to prism formation. Lastly, we report absorption and fluorescence properties of synthesized oligothiophenes and oligothiophene-ruthenium complexes that are bound to CdSe nanoparticles. Their ability to act as sensitizers and charge transfer junctions was tested. It was found that fluorescence of CdSe nanoparticles was quenched when they were bound to the oligothiophenes, and that the fluorescence of the oligothiophenes was also quenched. The fluorescence lifetimes of the quenched species were shortened.

Over 70% of the Earth s economically recoverable nickel (Ni) resides in laterite ore deposits, however they account for less than half of the current global nickel production. During laterization, nickel and other soluble ions are taken into solution before re-precipitating within iron oxide minerals in the limonite zone, or as serpentines and other phyllosilicates in the layers below this zone. It is these laterite deposits that show the greatest potential for low energy, environmentally conscious processing. The major host of nickel in the limonite zone is the iron-oxyhydroxide mineral goethite, α-FeOOH, where up to 4 mol% Ni has been reported in natural specimens, and even higher levels in synthetic samples (5.5 mol%). The Ni is assumed to be incorporated in the crystal structure of the goethite, but previous characterisation work only demonstrated a weak to moderate correlation of mineral structure change with the nickel content in goethite. Mining companies working on the extraction and recovery of nickel from the limonite zone of lateritic deposits have noticed that the ease with which nickel can be extracted varies greatly; goethite rich ores that appear to have similar mineralogies/geologies can display extreme variation in their leachability. It is not clear why the ores behave in this way, but in order for extraction techniques and subsequent recovery of nickel to be improved, the reasons behind this variability need to be understood. The lateritic ore materials from which nickel is extracted are generally made up of a number of different mineral phases. The multiphase nature of the samples means that characterisation of the goethite-type phases from these materials is challenging. To simplify the system and allow the association of Ni into goethite and/or other iron oxyhydroxide phases to be studied in a controlled environment, a synthetic study was carried out. Ni-bearing goethites have been synthesised at a series of different temperatures and characterised by a range of analytical techniques including PXRD, IR, Raman, TGA, ICP-OES, SEM and TEM. It was found that a second phase, ferrihydrite, co-existed with the goethites, the proportion of which increased at lower synthesis temperatures and with increasing amounts of Ni. Ferrihydrite is known to be a precursor phase in the formation of goethite, but its poorly crystalline nature makes it difficult to identify using standard characterisation techniques such as PXRD. The introduction of Ni to the system increases the stability of the ferrihydrite phase, inhibiting its transformation to goethite. It is believed that some of the Ni thought to be incorporated into goethite could actually reside in an undetected ferrihydrite phase, which could account for the differences observed in the leachability of natural materials. Characterisation techniques were investigated to try and determine a simple way to identify ferrihydrite in these systems, which could ideally be used in the field to identify the presence of ferrihydrite in goethite rich ore materials. Thermal analysis proved to be particularly promising as a technique which could be used to identify ferrihydrite rich deposits before extraction, enabling the most efficient and environmentally conscious metal recovery process for each deposit to be identified. In order to investigate the way in which Ni partitions itself between structural incorporation into goethite and association with a secondary ferrihydrite phase, a new washing technique was developed using EDTA, which is capable of selectively removing the ferrihydrite phase whilst leaving the goethite intact. This investigation suggests that a maximum of ~2.5 mol% of Ni is structurally incorporated into goethite, regardless of how much is added during the synthesis. Any excess nickel, above that which is substituted into the goethite structure, was found to be associated with the poorly crystalline ferrihydrite phase. Despite being considered a metastable phase, the increased stability of ferrihydrite resulting from the presence of Ni suggests that it may persist in laterite deposits within geological systems. If ferrihydrite is indeed present in nickeliferous laterites, it may be a significant host for Ni, and potentially many other critical elements. Based on the methodology developed whilst studying synthetic samples, a characterisation program for materials from lateritic ore deposits was conducted to investigate the presence of ferrihydrite in natural systems. From the research presented and discussed in this thesis, proof of the presence or absence of ferrihydrite in laterite systems, causing variations in the leachability of the ore materials, could not be conclusively established. The thermal analysis technique developed here successfully identified and quantified ferrihydrite in the presence of goethite in synthetic systems, and showed great potential when used to characterise the lateritic goethite samples, certainly suggesting that ferrihydrite could be present in these natural ore materials. With further refinement of the methodology, to enable a larger range of sample types to be accurately analysed, TGA is a technique which could be used as a screening tool for laterite ores.