A highly self-ordered hexagonal array of cylindrical pores has been fabricated by anodizing a thin film of Al on substrate and subsequent growth of GaN and InGaN in these nanoholes has been performed. This AAO template-based synthesis method provides a low cost process to fabricate GaN-based nanomaterials fabrication. / Singapore-MIT Alliance (SMA)

This thesis describes a method of growing a highly adherent nano-porous alumina coating on titanium implant materials, a design which might be useful in hard tissue replacement. Alumina layers were formed by anodisation of aluminium, which had been deposited on titanium and titanium alloys by electron beam evaporation. Mechanical testing showed the coatings’ shear and tensile strength to be ~20MPa and ~10MPa respectively. Human osteoblasts were cultured on purchased membranes, produced in the same way with similar characteristics as the coating mentioned above. Cell viability, proliferation and phenotype were assessed by measuring redox reactions, DNA, tritiated thymidine incorporation and alkaline phosphatase production. Results showed normal osteoblastic growth patterns with increasing cell numbers the first two weeks after which cell growth decreased and alkaline phosphatase production increased, indicating that osteoblastic phenotype was retained on the alumina. Flattened cell morphology with filipodia attached to the pores of the material was seen. Implants frequently trigger inflammatory responses due to accumulation and activation of cells such as polymorphonuclear granulocytes (PMN), also called neutrophils. Activation and morphology of human PMN in response to nano-porous alumina with two pore sizes (20 and 200 nm) was investigated by luminol-amplified chemiluminescence, granule enzyme deposition measurement, optical and scanning electron microscopy. Activation was observed on both membrane types, however less pronounced on the 200 nm alumina. For both membranes a decrease in activation was seen after coating with fibrinogen, collagen I and serum (more pronounced for the two latter). On fibrinogen-coated alumina many flattened cells were observed, indicating frustrated phagocytosis. Finally when culturing osteoblasts on non-coated and collagen-coated membranes (after exposure to PMN) many more cells had established on the protein-coated surface after 24 h. The overall results indicate that it might be possible to produce a novel bone implant coating by anodisation of aluminium deposited on titanium and that this material will support osteoblast adhesion and proliferation. Furthermore neutrophil activation can be suppressed when coating the alumina with collagen I, which is beneficial considering the fact that this protein also is essential for bone formation.

Made available in DSpace on 2014-06-11T19:23:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-24Bitstream added on 2014-06-13T20:50:23Z : No. of bitstreams: 1 santos_jc_me_bauru.pdf: 1909289 bytes, checksum: 46f1166eec4b53fcdc6e5fe6a3b31b70 (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Neste trabalho foi realizada a deposição através da técnica de evaporação resistiva, de filmes finos de GaAs (arseneto de gálio) e de Al (alumínio) com posterior oxidação deste último, formando 'Al IND. 2''O IND. 3' (óxido de alumínio ou alumina) e a caracterização dos filmes de GaAs e da heteroestrutura formada por 'Al IND. 2''O IND. 3' e GaAs. A confecção do dispositivo combinando estes compostos serviu para a investigação das características relevantes do sistema para potencial aplicação em transistores. O trabalho compreendeu investigação sobre as condições de deposição, e foram avaliadas principalmente as características elétricas dos filmes produzidos individualmente. Os resultados apresentados incluem: resistividade em função da temperatura, corrente-voltagem em função da temperatura, difração de raios-X e transmitância na região do infravermelho. Para caracterização do desempenho do sistema 'Al IND. 2''O IND. 3'/GaAs, um transistor simples foi construído sob um substrato de vidro borossilicato com uma camada de GaAs e outra de 'Al IND. 2''O IND. 3'. Os contatos de fonte, dreno e gate foram feitos de In. Essa estrutura permite a medida da corrente de fuga e a avaliação de outras características do sistema. Neste dispositivo foram avaliadas as características corrente-voltagem em função da temperatura, e também a interação com luz, já que GaAs, por apresentar gap direto, torna-se atraente para aplicações opto-eletrônicas. Assim medidas de elétricas foto-induzidas foram realizadas com excitação com fontes de luz branca. Com o intuito de se avaliar a qualidade dos filmes de GaAs obtidos pela evaporação resistiva, tanto a caracterização estrutural quando elétrica também foram feitas em filmes finos de GaAs depositados por sputtering, de modo a se ter um padrão de comparação. / In this work, the deposition of GaAs (gallium arsenide) and Al (aluminum) thin films is carried out by the resistive evaporation technique. In the latter case, an oxidation of the film is accomplished, leading to 'Al IND. 2''O IND. 3' (alumina) formation. The characterization of GaAs thin films and the heterostructure formed by 'Al IND. 2''O IND. 3' and GaAs is also carried out. The elaboration of the device combining these compounds allows investigating the relevant characteristics of this system to potential application in transistors. The work evolved investigation on the deposition conditions, and the electrical characteristics of the films were also evaluated separately. Results includes: resistivity as function of temperature, X-ray diffraction and near infrared transmittance. For characterization of the performance of the 'Al IND. 2''O IND. 3'/GaAs system, a simple transistor was built on a borosilicate glass substrate, with a 'Al IND. 2''O IND. 3' layer on top of a GaAs layer. The contacts of source, drain and gate were done using In. This structure allows evaluating the leak current and other characteristics of this system. In this device, it was evaluated the current - voltage characteristics and the interaction with light, because GaAs, due to its direct bandgap, become very attractive for opto-electronic applications. The, the photo-induced electrical measurements were done under excitation with white light. Aiming the evaluation of the quality of films deposited by the resistive evaporation technique, electrical as well as structural characterization were also carried out for GaAs thin films deposited by sputtering, in order to have a comparing parameter.

Objetivo: O objetivo do trabalho foi caracterizar e comparar sistemas cerâmicos aluminizados infiltrados por vidro, por meio de difração por RX, microscopia eletrônica de varredura e resistência à flexão uniaxial em três pontos. Os sistemas cerâmicos utilizados foram: (IC)- In-Ceram Alumina (VITA), (VC)- Vitro-Ceram (Angelus) e (AG)- Alglass (Celmat). A fase cristalina de cada material foi identificada por meio de difração por RX. Dez espécimes em forma de barra (25X4X1,20,1) de cada material foram produzidos seguindo as instruções do fabricante de acordo com a ISO 6872. Os espécimes foram levados em uma máquina de ensaio universal para avaliação da resistência à flexão em três pontos, com carga de 500Kgf, velocidade de 0,5mm/min e distância entre os apoios de 15mm. Os dados foram submetidos a análise estatística ANOVA (p<0,01). Os espécimes fraturados foram observados no MEV em diversas condições: superfície jateada, superfície polida, superfície fraturada e alumina sem infiltração. Resultados: Foi identificada uma segunda fase cristalina de zircônia dopada com Ítrio no VC. Os valores médios de resistência à flexão foram (MPa): VC (48338,3)= IC (456,629,4) > AG(263,837,8) (nível de 1% de significância). A micromorfologia dos sistemas apresentou características bem distintas, com diferenças em relação ao tamanho e distribuição das partículas de alumina e capacidade de molhamento do vidro de infiltração. A análise da fratura demonstrou comportamento semelhante contornando a maioria dos grãos de alumina e atravessando outros. Conclusões: 1 - O sistema Vitro-Ceram apresenta uma segunda fase cristalina composta por Zircônia dopada por Ítrio enquanto que os sistemas Alglass In-Ceram apresentam apenas Alumina na sua fase cristalina. 2 - Os sistemas In-Ceram e Vitro-Ceram apresentaram valores de resistência à flexão estatisticamente semelhante entre si e maiores que o Alglass. 3 - O sistema Alglass apresentou diversas áreas sem infiltração por vidro, o que pode estar relacionado com resultados mecânicos inferiores. 4 - A propagação da fratura se dá do mesmo modo nos três sistemas, percorrendo preferencialmente pela fase vítrea e, eventualmente, atravessando uma partícula de alumina. / Objective: The purpose of this study was to characterize and compare glass-infused alumina-based ceramic systems by using X-Ray diffraction, scanning electron microscopy (SEM) and &#64258;exural strength with a three-point bending test. The ceramic systems used were: (IC)- In-Ceram Alumina (VITA), (VC)- Vitro-Ceram (Angelus) and (AG)- Alglass (Celmat). The crystalline phase of each material was identified through X-Ray diffraction. Ten bar specimens (25X4X1,20.1) of each material were produced following the manufacturers instructions according to ISO 6872. The specimens were taken to a universal testing machine to evaluate &#64258;exural strength with a three-point bending test, with a constant load of 500Kgf, crosshead speed of 0,5mm/min and a 15mm distance between supports. The data was submitted to ANOVA (p<0.01) statistical analysis. The fractured specimens underwent SEM analysis in different conditions: sandblasted surface, polished surface, fractured surface and alumina without infiltration. Results: a second crystalline phase of yttrium-stabilized zirconia was identified in VC. Mean values of &#64258;exural strength were (MPa): VC (48338.3)= IC (456,629.4) > AG(263,837.8). The micro morphology presented distinct characteristics for each system, with differences in relation to size and distribution of the alumina particles, and the ability of glass infiltration. Fracture analysis showed similar behavior contouring most alumina particles and though others. Conclusions: 1 Vitro-Ceram system presents a second crystalline phase composed of yttrium-stabilized zirconia while Alglass and In-Ceram presented only alumina in their crystalline phase. 2 In-Ceram and Vitro-Ceram systems presented higher flexural strength values than Alglass and statistically similar between them. 3 Alglass system presented several areas where glass infiltration did not occur, which might explain its worse mechanical results. 4 The mode of crack propagation showed to be similar in all three systems, being most frequently observed through the glassy phase and sometimes though an alumina particle.

Orientador: Prof. Dr. Dalmo Mandelli / Tese (doutorado) - Universidade Federal do ABC. Programa de Pós-Graduação em Ciência e Tecnologia/Química, 2017. / A oxidacao de compostos organicos tem sido muito estudada nas ultimas decadas e e uma das areas de estudo mais atrativas da quimica moderna. Este tipo de reacao leva a obtencao de produtos de grande aplicacao na industria farmaceutica, de plasticos e fragrancias, como alcoois, cetonas e epoxidos. Varios trabalhos tem sido realizados no sentido de se desenvolver novos catalisadores ativos e seletivos, que tambem possuam custo e toxicidade relativamente baixos, com a finalidade de se obter processos que levem a quantidade cada vez menor de subprodutos e residuos de reacao, dentro do contexto da quimica-verde. Este trabalho foi dividido em duas partes, consistindo a primeira de um Planejamento de Experimentos Fracionario (27-4), nos quais foi possivel definir as principais variaveis que afetam a atividade catalitica dos oxidos de aluminio e galio, a saber: pH final, velocidade de resfriamento e solvente. Na segunda parte, estas variaveis foram exploradas em um Planejamento de Experimentos Completo 23. Por meio das analises de Fisissorcao de N2 e Dessorcao Termoprogramada de Amonia, foi possivel correlacionar algumas das propriedades fisico-quimicas dos catalisadores sintetizados com sua atividade catalitica. Com relacao a acidez dos catalisadores, pH e solvente apresentaram-se como as variaveis mais significativas: houve, em media, reducao da acidez em 1,0 mmolNH3 g-1 ao se realizar a sintese em pH 10 ao inves de pH 9 para Al2O3 e 1,1 mmolNH3 g-1 para Ga2O3; a troca de solvente de etilenoglicol por glicerol causou reducao de 0,60 mmolNH3 g-1 para Al2O3, enquanto houve um aumento de 1,2 mmolNH3 g-1 para Ga2O3. Para as propriedades fisicas, o solvente foi a variavel mais importante; os valores de area superficial, variaram entre 265 e 479 m2 g-1 para Al2O3, havendo um aumento medio de 136 m2 g-1 ao se utilizar glicerol, enquanto que os valores obtidos para Ga2O3 ficaram entre 81 e 280 m2 g-1, com efeito de positivo de 95 m2 g-1 ao se substituir etilenoglicol por glicerol. Com relacao as propriedades cataliticas, verificou-se que o uso de glicerol como solvente resultou em aumento medio de 10,1 % nos rendimentos para Al2O3 durante a epoxidacao de cicloocteno; os melhores resultados foram obtidos com rendimento de 53 % apos 6 h de reacao. Por outro lado, todos os oxidos de galio apresentaram rendimentos superiores a 98 % apos 4 h. A adicao dos acidos HNO3 e TFA como co-catalisadores da reacao de epoxidacao de cicloocteno com Al2O3 e Acido Acetico como co-catalisador do Ga2O3 causaram aumento substancial na velocidade inicial, mais que dobrando seu valor ao se utilizar os mesmos; por outro lado, a adicao de bases, como PCA, levaram a reducoes na atividade catalitica dos sistemas. Outros alquenos, como decen-1-eno, e terpenos, incluindo limoneno, ¿¿-pineno, linalol, geraniol e citral foram testados, resultando em rendimentos que variaram entre 19 e 51 % para A2O3 (10 h) e entre 31 e 100 % para Ga2O3 (7 h). / The oxidation of organic compounds has been much studied in recent decades and is one of the most attractive areas of study in modern chemistry. This type of reaction leads to the obtaining of products of great application in the pharmaceutical, plastics and fragrances industry, like alcohols, ketones and epoxides. Several works have been carried out in order to develop new active and selective catalysts, which also have relatively low cost and toxicity, in order to obtain processes that lead to the decreasing amount of by-products and reaction residues within the context of green chemistry. This work was divided in two parts, consisting the first of a Fractional Factorial Designs (27-4), in which it was possible to define the main variables that affect the catalytic activity of aluminum and gallium oxides, namely: final pH, cooling rate and solvent. In the second part, these variables were explored in a Complete Factorial Designs 23. Through the analysis of N2 Fisissorption and Thermoprogrammed Ammonia Desorption, it was possible to correlate some of the physicochemical properties of the catalysts synthesized with their catalytic activity. In relation to the acidity of the catalysts, pH and solvent were the most significant variables: there was, on average, acidity reduction of 1.0 mmolNH3 g-1 when the synthesis was performed at pH 10 instead of pH 9 for Al2O3 and 1.1 mmolNH3 g-1 for Ga2O3; The exchange of ethylene glycol solvent for glycerol caused a reduction of 0.60 mmolNH3 g-1 to Al2O3, while there was an increase of 1.2 mmolNH3 g-1 for Ga2O3. For the physical properties, the solvent was the most important variable; the values of surface area ranged from 265 to 479 m² g-1 for Al2O3, with an average increase of 136 m² g-1 when using glycerol, while Ga2O3 values were between 81 and 280 m² g-1, with positive effect of 95 m² g-1 when ethylene glycol was substituted by glycerol. Regarding the catalytic properties, it was found that the use of glycerol as solvent resulted in an average increase of 10,1 % in the yields for Al2O3 during cyclooctene epoxidation; the best results were obtained with 53% yield after 6 h of reaction. On the other hand, all gallium oxides presented yields higher than 98% after 4 h. The addition of the HNO3 and TFA acids as co-catalysts of the cyclooctene epoxidation reaction with Al2O3 and acetic acid as co-catalyst of Ga2O3 caused a substantial increase in the initial velocity, rather than doubling their values; on the other hand, the addition of bases, such as PCA, led to reductions in the catalytic activity of the systems. Other alkenes, such as dec-1-ene, and terpenes, including limonene, á-pinene, linalool, geraniol and citral were tested, giving yields ranging from 19 to 51 % for A2O3 (10 h) and between 31 and 100 % for Ga2O3 (7 h).

Objetivo: O objetivo do trabalho foi caracterizar e comparar sistemas cerâmicos aluminizados infiltrados por vidro, por meio de difração por RX, microscopia eletrônica de varredura e resistência à flexão uniaxial em três pontos. Os sistemas cerâmicos utilizados foram: (IC)- In-Ceram Alumina (VITA), (VC)- Vitro-Ceram (Angelus) e (AG)- Alglass (Celmat). A fase cristalina de cada material foi identificada por meio de difração por RX. Dez espécimes em forma de barra (25X4X1,20,1) de cada material foram produzidos seguindo as instruções do fabricante de acordo com a ISO 6872. Os espécimes foram levados em uma máquina de ensaio universal para avaliação da resistência à flexão em três pontos, com carga de 500Kgf, velocidade de 0,5mm/min e distância entre os apoios de 15mm. Os dados foram submetidos a análise estatística ANOVA (p<0,01). Os espécimes fraturados foram observados no MEV em diversas condições: superfície jateada, superfície polida, superfície fraturada e alumina sem infiltração. Resultados: Foi identificada uma segunda fase cristalina de zircônia dopada com Ítrio no VC. Os valores médios de resistência à flexão foram (MPa): VC (48338,3)= IC (456,629,4) > AG(263,837,8) (nível de 1% de significância). A micromorfologia dos sistemas apresentou características bem distintas, com diferenças em relação ao tamanho e distribuição das partículas de alumina e capacidade de molhamento do vidro de infiltração. A análise da fratura demonstrou comportamento semelhante contornando a maioria dos grãos de alumina e atravessando outros. Conclusões: 1 - O sistema Vitro-Ceram apresenta uma segunda fase cristalina composta por Zircônia dopada por Ítrio enquanto que os sistemas Alglass In-Ceram apresentam apenas Alumina na sua fase cristalina. 2 - Os sistemas In-Ceram e Vitro-Ceram apresentaram valores de resistência à flexão estatisticamente semelhante entre si e maiores que o Alglass. 3 - O sistema Alglass apresentou diversas áreas sem infiltração por vidro, o que pode estar relacionado com resultados mecânicos inferiores. 4 - A propagação da fratura se dá do mesmo modo nos três sistemas, percorrendo preferencialmente pela fase vítrea e, eventualmente, atravessando uma partícula de alumina. / Objective: The purpose of this study was to characterize and compare glass-infused alumina-based ceramic systems by using X-Ray diffraction, scanning electron microscopy (SEM) and &#64258;exural strength with a three-point bending test. The ceramic systems used were: (IC)- In-Ceram Alumina (VITA), (VC)- Vitro-Ceram (Angelus) and (AG)- Alglass (Celmat). The crystalline phase of each material was identified through X-Ray diffraction. Ten bar specimens (25X4X1,20.1) of each material were produced following the manufacturers instructions according to ISO 6872. The specimens were taken to a universal testing machine to evaluate &#64258;exural strength with a three-point bending test, with a constant load of 500Kgf, crosshead speed of 0,5mm/min and a 15mm distance between supports. The data was submitted to ANOVA (p<0.01) statistical analysis. The fractured specimens underwent SEM analysis in different conditions: sandblasted surface, polished surface, fractured surface and alumina without infiltration. Results: a second crystalline phase of yttrium-stabilized zirconia was identified in VC. Mean values of &#64258;exural strength were (MPa): VC (48338.3)= IC (456,629.4) > AG(263,837.8). The micro morphology presented distinct characteristics for each system, with differences in relation to size and distribution of the alumina particles, and the ability of glass infiltration. Fracture analysis showed similar behavior contouring most alumina particles and though others. Conclusions: 1 Vitro-Ceram system presents a second crystalline phase composed of yttrium-stabilized zirconia while Alglass and In-Ceram presented only alumina in their crystalline phase. 2 In-Ceram and Vitro-Ceram systems presented higher flexural strength values than Alglass and statistically similar between them. 3 Alglass system presented several areas where glass infiltration did not occur, which might explain its worse mechanical results. 4 The mode of crack propagation showed to be similar in all three systems, being most frequently observed through the glassy phase and sometimes though an alumina particle.

Abstract The aim of the thesis is to expand the knowledge of the catalytic properties of platinum-loaded zeolite catalysts in the reduction of NOx by hydrocarbons. The work is divided into three parts. First the recent literature of zeolite catalysts has been introduced, secondly the adsorption capacity, activity, and acidity of the catalysts have been studied by TPD and IR techniques, and thirdly the derived reaction mechanisms based on the obtained data are presented. Parent and 1 wt-% Pt-loaded ZSM-5, Beta, Y, and Ferrierite zeolite catalysts have been studied in the C3H6-assisted reduction of NO. The Pd/Al2O3-based catalyst was used as a reference material for the reaction mechanistic studies. Several experimental techniques (in situ DRIFT, activity measurements, CO chemisorption, N2 physisorption, TPD, and TEM) have been used for the characterisation of the catalysts properties. The IR technique was used as the main technique for the determination of activities, surface species, and the acidic properties of the zeolite-based catalysts. The activity studies carried out by the gaseous FTIR technique provide information on the desired reaction products as well as the undesired by-products. The detection and identification of the surface species as well as the reaction intermediates formed were done by the DRIFT method. The activity experiments indicate the effectiveness of the Pt-loaded zeolite catalysts. The reduction of NO was found to decrease in the order: Pt/Beta > Pt/Y > Pt/Ferrierite > Pt/ZSM-5 in the conditions with excess O2. Platinum can be concluded to have an effect on O2 and NO dissociation. Oxidation reactions of NO to NO2 and propene to CO2 were observed to be more intense over the platinum-loaded zeolites than over the parent zeolites. In this work the reaction mechanisms for the C3H6-SCR of NO were derived over the Pt-loaded zeolite as well as the Pd/alumina catalysts based on the data obtained by DRIFT and activity experiments. The kinetics for the NO reduction by CO over Pd/Al2O3 was also derived. With the methods employed, the mechanistic steps over the Pt-loaded zeolites and Pd/Al2O3-based catalysts could be derived quite precisely and easily for C3H6-SCR of NO. Reaction routes were determined to go via different formations of intermediates over the two catalysts, i.e. via organonitrogen and isocyanate routes, respectively. The IR techniques were discovered to be effective tools in applied engineering studies.

A study was conducted on sol-gel synthesis of an adsorbent (phosphotungstic acid embedded in silica gel, H-PTA/SiO­2) of radioactive cesium. A novelty of this work is covalent bonding of PTA to the surface of solid support that prevents leaching from the surface of the material. The sample was granulated with a binder, aluminium oxide (γ-Al2O3). Solid-state NMR and FT-IR spectroscopy were used to confirm the presence of Keggin units of PTA in the bound materials. Thermal analysis of H-PTA/SiO­2 - γ-Al2O3 (50 %) showed that the water content in the bound material was appreciably lower than in the pure adsorbent. Quantitative determination of surface acidity of porous materials is an important analytical problem in characterization of the adsorbents. This problem was solved by reversed titration after saturation of the materials by anhydrous solution of pyridine. Batch and column adsorption tests showed that the adsorbent demonstrated high adsorption capacities towards cesium.

The main purpose of the master thesis project is to investigate the influence of selected serine protease inhibitors (SPI) on the catalytic action of the serine proteases chymotrypsin and trypsin, in a conjugated and non-conjugated state. The inhibitors included for this study were extracted from Solanum tuberosum, i.e.common potato. The purification method included in this study consist of crude extraction by mixer, followed by a salt-out procedure with ammonium sulphate. Further purification steps were cation exchange chromatography and, finally, gel filtration to obtain SPI of high purity. The purified sample was then characterized by SDS-page and kinetic activity measurement of trypsin and chymotrypsin action on synthetic substrate derivate, N-Benzoyl-DL-arginine-4-nitroanilide hydrochloride (BAPA) and N-Succinyl-L-phenylalanine-p-nitroaniline (SFpNA) respectively. The characterization showed inhibitory inactivation of both pancreatic proteases. This would indicate successful extraction of SPI. To investigate inhibitory action in a conjugated state, either enzyme or inhibitor was immobilized onto aluminium oxide membranes. Then two different experimental setups were tested, called experiment 1 and 2. In experiment 1, the inhibitor was immobilized and the interaction was monitored from a retention shift of enzyme flow-through compared to a blank column, using detection at 280 nm of the enzyme. In experiment 2 the enzyme was instead immobilized and a mixture of inhibitor and substrate was circulated with monitoring of the catalytic activity. The main goal was thus to measure the effects on the kinetics in the conjugated state compared to enzyme and inhibitor in the free state. The result from both experiment 1 and 2 did not yield consistent and reliable result so the discussed method should be regarded as preliminary results. The study also includes investigation of inhibitor-enzyme interaction as revealed by molecular mass data to determine complex formation. This part was conducted with static light scattering analysis to determine the stoichiometry for the interaction between pancreas proteases and the inhibitor. Results from light scattering showed promising indication of many-to-one interaction between enzyme and inhibitor, which have been seen by previous studies. It should be considered a preliminary result as complex formation does not exclude aggregation of enzymes or inhibitor in the solution.

Anlagen zur Herstellung von Synthesegas (CO·H2) aus kohlenstoffhaltigen Rohstoffen werden durch hohe Temperaturen bis zu 1600 °C und Drücken bis zu 50 bar beansprucht und benötigen daher Schutz durch eine feuerfeste Ausmauerung. Zur Steigerung der Effizienz und Lebensdauer solcher Vergasungsanlagen ist die Entwicklung neuer keramischer Hochtemperaturwerkstoffe erforderlich. Solch ein Material stellt eine Al2O3-reiche Gießmasse dar, welche durch den gezielten Einsatz verschiedener ZrO2- und TiO2-Gehalte optimiert wurde. Es hat sich gezeigt, dass bereits durch die Zugabe geringer Mengen an ZrO2 bzw. TiO2 sowohl die Temperaturwechselbeständigkeit als auch die Korrosionsbeständigkeit von Al2O3 gegenüber Kohleschlacken erheblich verbessert werden kann, was auf die Ausbildung einer Spinell-Schutzschicht während des Korrosionsvorgangs zurückzuführen ist.