Made available in DSpace on 2014-12-17T15:41:53Z (GMT). No. of bitstreams: 1 JoseABLRA_DISSERT.pdf: 2347923 bytes, checksum: 6e0dcb6d004a500ef5b9305459cc4e95 (MD5) Previous issue date: 2010-05-27 / Mesoporous molecular sieves of MCM-41 type are considered as promising support for metal in the refining processes of petroleum-based materials as catalysts and adsorbents for environmental protection. In this work, mesoporous molecular sieves MCM-41 were modified with different rare earth ions (La, Eu e Yb) for the obtaining nanostrutured materials with catalytic properties. The catalysts were synthesized by the hydrothermal method at 100oC for 120 h, presenting, all the samples, in the gel of synthesis molar ratio Si/Ln = 50. The obtained materials after calcination at 500oC for 2 h were characterized by XRD, surface area BET, TG/DTG, FTIR, and hydrothermal stability at 700?C. The XRD analysis of the catalysts indicated that the materials containing rare earth presented characteristic hexagonal structure of the mesoporous materials of the type MCM-41. The TG curves showed that the decomposition of the structural template occurs in the materials at temperatures lower than 500oC. The samples presented variations as the specific superficial area, average diameter of pores and thickness of the silica wall, as a function of the nature of the rare earth impregnated in the mesoporous material. Hydrotermal stability was evaluated through the exposition of the materials to water vapour at 700?C. The thiophene adsorptions reach a maximum at 80% of conversion and incorporation of the rare earths showed influence in the process. Adsorption capacity followed the sequence: Yb-MCM-41 < La-MCM-41 < Eu-MCM-41 < MCM-41 / As peneiras moleculares mesoporosas do tipo MCM-41 s?o consideradas promissoras como suporte para metais em processos de refino de materiais a base de petr?leo, como catalisadores e como adsorventes para prote??o ambiental. Neste trabalho a peneira molecular mesoporosa tipo MCM-41 foi modificada com diferentes terras raras (La, Eu e Yb) para a obten??o de materiais nanoestruturados com propriedades catal?ticas. Os catalisadores foram sintetizados pelo m?todo hidrot?rmico a 100 oC por 120 horas, apresentando, todas as amostras, no gel de s?ntese raz?o molar Si/Ln = 50. Os materiais resultantes, ap?s calcina??o a 500 oC por 2 horas, foram caracterizados por: DRX, ?rea superficial pelo m?todo de BET, TG/DTG, FTIR e testes hidrot?rmicos a 700oC. As an?lises de DRX dos catalisadores indicaram que os materiais contendo as terras raras apresentaram estrutura hexagonal caracter?stica do material mesoporoso tipo MCM-41. As curvas TG mostraram que a decomposi??o do direcionador estrutural ocorre nos materiais em temperaturas inferiores a 500oC. As amostras apresentaram varia??es quanto ? ?rea superficial espec?fica, di?metro m?dio de poros e espessura da parede de s?lica, em fun??o da natureza da terra rara impregnada no material mesoporoso. A estabilidade hidrot?rmica foi avaliada atrav?s da exposi??o dos materiais a vapor d ?gua a 700oC. A adsor??o de tiofeno atingiu valores m?ximos de 80% e a incorpora??o das terras raras influenciaram no processo. A ordem crescente de capacidade de adsor??o seguiu a seguinte seq??ncia: Yb-MCM-41 < La-MCM-41 < Eu-MCM-41 < MCM-41

Bien que le rôle actif des sucres soit connu dans la stabilisation des membranes cellulaires lors de fortes déshydratations, il s'avère que les processus à l'origine de cette protection ne sont pas encore bien compris. Néanmoins, la très grande affinité de l'eau pour le sucre, comme en témoigne la formation de très nombreuses liaisons hydrogène, est semble-t-il responsable en partie de cette propriété exceptionnelle. L'étude expérimentale de la dynamique des molécules de sucre et d'eau permettra ainsi de quantifier l'importance de ces interactions. <br /> Dans ce travail, nous nous sommes principalement intéressés à des solutions de mono- et disaccharides (glucose, fructose et tréhalose). La diffusion quasi-élastique des neutrons a permis de mesurer, à l'échelle de la picoseconde, la dynamique de l'eau et du sucre en solution et sous confinement dans des matériaux poreux présentant un mimétisme d'échelle avec le vivant. Les deux matrices sélectionnées, c'est-à-dire un gel de silice aqueux et des nanosphères de silice mésoporeuse de type MCM-41, qui présentent des diamètres de pores de 18 et 3 nm respectivement, ont été caractérisées grâce à un large panel de techniques expérimentales (SANS, MET, MEB, Spectroscopie Raman, BET, DRX). L'effet du confinement sur la dynamique et sur les transitions de phase solide-liquide a ainsi pu être exploré, ainsi que l'effet protecteur des sucres grâce à une étude de déshydratation in-situ suivie par diffusion des neutrons aux petits angles.

Organic-inorganic nanostructured composites are nowadays integrated in the field of material science and technology. They are used as advanced materials directly or as precursors to novel composites with potential applications in optics, mechanics, energy, catalysis and medicine. Many properties of these complex materials depend on conformational rearrangements in their inherently dynamic organic parts. The focus of this thesis is on the study of the molecular mobility in ordered nanostructured composites and lyotropic mesophases and also on the development of relevant solid-state NMR methodologies. In this work, a number of new experimental approaches were proposed for dipolar NMR spectroscopy for characterizing molecular dynamics with atomic-level resolution in complex solids and liquids. A new acquisition scheme for two-dimensional dipolar spectroscopy has been developed in order to expand the spectral window in the indirect dimension while using limited radio-frequency power. Selective decoupling of spin-1 nuclei for sign-sensitive determination of the heteronuclear dipolar coupling has been described. A new dipolar recoupling technique for rotating samples has been developed to achieve high dipolar resolution in a wide range of dipolar coupling strength. The experimental techniques developed herein are capable of delivering detailed model-independent information on molecular motional parameters that can be directly compared in different composites and their bulk analogs. Solid-state NMR has been applied to study the local molecular dynamics of surfactant molecules in nanostructured organic-inorganic composites of different morphologies. On the basis of the experimental profiles of local order parameters, physical motional models for the confined surfactant molecules were put forward. In layered materials, a number of motional modes of surfactant molecules were observed depending on sample composition. These modes ranged from essentially immobilized rigid states to highly flexible and anisotropically tumbling states. In ordered hexagonal silica, highly dynamic conformationally disordered chains with restricted motion of the segments close to the head group have been found. The results presented in this thesis provide a step towards the comprehensive characterization of the molecular states and understanding the great variability of the molecular assemblies in advanced nanostructured organic−inorganic composite materials. / <p>QC 20150225</p>

Submitted by Maria Medeiros (maria.dilva1@ufcg.edu.br) on 2018-10-19T13:06:58Z No. of bitstreams: 1 GUSTAVO MEDEIROS DE PAULA - DISSERTAÇÃO (PPGEQ) 2017.pdf: 3627178 bytes, checksum: f30200badddb75701ea0fec49346e30e (MD5) / Made available in DSpace on 2018-10-19T13:06:58Z (GMT). No. of bitstreams: 1 GUSTAVO MEDEIROS DE PAULA - DISSERTAÇÃO (PPGEQ) 2017.pdf: 3627178 bytes, checksum: f30200badddb75701ea0fec49346e30e (MD5) Previous issue date: 2017-03-30 / Capes / Este trabalho teve como objetivo sintetizar as peneiras moleculares MCM-41 e SBA-15, utilizando fontes alternativas de sílica, e preparar os catalisadores MoO3/MCM-41 e MoO3/SBA-15 e avaliar seu potencial catalítico na reação de transesterificação de óleo de soja para produção de biodiesel. As peneiras moleculares MCM-41 e SBA-15 foram sintetizadas empregando TEOS, argila chocolate B, cinzas de casca de arroz e pó de vidro como fontes de sílica. As fontes alternativas de sílica foram previamente dissolvidas em solução de NaOH (1 mol.L-1) a 100ºC por 6 horas. Em seguida, as misturas foram filtradas, e os filtrados contendo sílica dissolvida foram armazenados para posterior utilização nas sínteses das peneiras moleculares. As sínteses da MCM-41 ocorreram em duas etapas, o envelhecimento térmico ocorreu a 28 ºC por 2 horas e as sínteses hidrotérmicas ocorreram a 150 ºC por 96 horas. As sínteses da SBA-15 foram realizadas em duas etapas, o envelhecimento térmico ocorreu a 35 ºC por 24 horas e as sínteses hidrotérmicas ocorreram a 100 ºC por 48 horas. Os produtos das sínteses foram, lavados com água destilada e secos a 60 ºC por 24 horas. A deposição do MoO3 sobre os suportes MCM-41 e SBA-15 foi realizada por meio de impregnação úmida utilizando-se solução aquosa de Heptamolibdato de Amónio (0,1 mol.L-1), seguida de calcinação. As matérias-primas, assim como as peneiras moleculares e os catalisadores foram caracterizadas por Difração de raios X (DRX), Espectroscopia de Fluorescência de Raios X por Energia Dispersiva (FRX-ED), Microscopia eletrônica de Varredura (MEV) e Espectroscopia na Região de Infravermelho por Transformada de Fourier (FTIR). Os catalisadores foram avaliados na reação de transesterificação do óleo de soja com etanol em reator batelada sem agitação, com temperatura de 100 ºC durante 3 horas. Os resultados de DRX e FRX-ED das fontes de sílica mostram que todas são compostas por sílica amorfa e cristalina, evidenciando o potencial dos materiais. Os resultados de DRX, MEV e FTIR das peneiras moleculares mostraram a eficácia dos processos de síntese da MCM-41 e SBA-15 e dos catalisadores MoO3/MCM-41 e MoO3/SBA-15 com todas as fontes de sílica. Os biodieseis obtidos foram caracterizados utilizando técnicas de determinação de massa específica, viscosidade cinemática e índice de acidez. Os produtos gerados evidenciaram o poder catalítico dos catalisadores, porém revelaram que as condições reacionais empregadas são insuficientes para produção de biodiesel B100. / The study aimed to synthesize the MCM-41 and SBA-15 molecular sieves, using alternative silica sources, and to prepare the MoO3/MCM-41 and MoO3/SBA-15 catalysts and to evaluate their catalytic potential in the transesterification reaction of soybean for biodiesel production. The MCM-41 and SBA-15 molecular sieves were synthesized using TEOS, chocolate B clay, rice husk ash and glass powder as silica sources. The molecular sieves were synthesized using a hydrothermal method. Alternative silica sources were previously dissolved in NaOH solution (1 mol.L-1), filtered and the filtrates containing silica in the liquid phase were stored for further use in the molecular sieve synthesis. The MCM-41 synthesis occurred in two steps, the thermal ageing occurred at 28 °C for 2 hours and the hydrothermal synthesis occurred at 150 °C for 96 hours. The SBA-15 synthesis occurred in two steps, the thermal ageing occurred at 35 °C for 24 hours and the hydrothermal synthesis occurred at 100 °C for 48 hours. The synthesis products were washed with distilled water, filtered, dried at 60 °C for 24 hours and calcined at 550 °C for 7 hours.The MoO3 deposition on MCM-41 and SBA-15 support was performed by means of wetness impregnation using an aqueous solution of 0,1 mol.L-1 Ammonium Heptamolybdate. After the impregnation process, the material was subjected to calcination. The samples were characterized by X-ray diffraction (XRD), Energy Dispersive X-Ray Fluorescence Spectroscopy (ED-XRF), Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FTIR). The catalysts were evaluated in the transesterification reaction of soybean oil with ethanol in a batch reactor without stirring at 100 ° C for 3 hours. The results of XRD and ED-XRF of the silica sources show that all are composed of amorphous and crystalline silica, evidencing the potential of the materials. The results of XRD, SEM and FTIR of the molecular sieves showed the efficiency of the synthesis of MCM-41 and SBA-15 and MoO3/MCM-41 and MoO3/SBA-15 catalysts with all silica sources. The biodiesel were characterized using techniques for determining specific mass, kinematic viscosity and acid index. The products generated evidenced the catalytic power of the catalysts, but revealed that the reaction conditions employed are insufficient for the production of B100 biodiesel.

This work describes the synthesis and characterization of the mesoporous material MCM-41 and a new functionalized mesoporous material, PABA-MCM-41, for use as adsorbents to remove the PAHs benzo[k]fluoranthene (B[k]F), benzo[a]pyrene (B[a]P), and benzo[b]fluoranthene (B[b]F). Both materials were synthesized using hydrothermal methods. PABA-MCM-41 was synthesized using a hydrothermal/co-condensation technique, with functionalization employing modified 4-aminobenzoic acid. The mesoporous materials were characterized using Fourier transform infrared spectroscopy (FTIR), small angle X-ray scattering (SAXS), nitrogen adsorption/desorption, scanning electron microscopy (SEM), and thermogravimetric analysis (TG). Batch adsorption experiments were employed to determine the effects of initial adsorbate concentration, contact time, and temperature on the removal of the PAHs. The co-condensation method was shown to be effective for the synthesis of functionalized PABA-MCM-41. The two mesoporous materials presented the hexagonal mesostructures typical of the M41S family, which were confirmed by the SAXS analyses and by the type IV isotherms with type H1 hysteresis. The materials possessed uniform mesopore size distributions, high surface areas, and were thermally stable. Adsorption tests showed that for both materials, the quantity adsorbed (qe) increased as the initial PAHs concentration was increased, with adsorption equilibrium reached in around 90 minutes. For adsorption by MCM-41, the equilibrium qe values were 12.49, 14.06, and 18.06 ìg g-1 for B[k]F, B[a]P, and B[b]F, respectively, while the corresponding values for the same PAHs were 22.51, 27.24, and 26.58 ìg g-1 when PABA-MCM-41 was used. The experimental kinetic data were fitted using the pseudo-second order model, and the Langmuir isotherm model was able to describe the process of PAH adsorption. At higher temperatures, there were increases in the initial adsorption rate and the kinetic constant for adsorption of the PAHs by PABA-MCM-41. The thermodynamic parameters indicated that the processes are spontaneous, endothermic, and with a tendency towards disorder of the system at the adsorbent/adsorbate interface. Functionalization of MCM-41 increased the efficiency of adsorption of the PAHs by 44.5, 48.4, and 32.0% for B[k]F, B[a]P, and B[b]F, respectively. / Este trabalho descreve a sintese e caracterizacao do material mesoporoso MCM-41 e do novo material mesoporoso funcionalizado PABA-MCM-41 para serem utilizados como materiais adsorventes na remocao dos HPAs benzo[k]fluoranteno (B[k]F), benzo[a]pireno (B[a]P) e benzo[b]fluoranteno (B[b]F). Os dois materiais foram sintetizados pelo metodo hidrotermal, sendo que PABA-MCM-41 foi sintetizado pelo metodo hidrotermal/co-condensacao, o qual foi funcionalizado pelo acido 4-aminobenzoico modificado. Os materiais mesoporosos sintetizados foram caracterizados por espectroscopia na regiao do infravermelho por transformada de Fourier (FTIR), espalhamento de raios-X a baixo angulo (SAXS), adsorcao/dessorcao de N2, microscopia eletronica de varredura (MEV) e analise termogravimetrica (TG). Os experimentos de adsorcao em batelada foram utilizados para determinar os efeitos da concentracao inicial do adsorbato, tempo de contato e temperatura na remocao dos HPAs B[k]F, B[a]P e B[b]F. O metodo da co-condensacao mostrou-se eficiente na sintese do material mesoporoso funcionalizado PABA-MCM-41. Os dois materiais mesoporosos apresentaram mesoestruturas hexagonais tipicas da familia M41S, as quais foram confirmadas por SAXS, com isotermas do tipo IV e histerese do tipo H1. Tambem, apresentaram distribuicao uniforme do tamanho de mesoporos, alta area superficial e estabilidade termica. Os ensaios de adsorcao mostraram que ocorreu um aumento da quantidade adsorvida (qe) com o aumento da concentracao inicial dos HPAs, isto para os dois materiais mesoporosos utilizados, sendo que o equilibrio de adsorcao foi alcancado em cerca de 90 minutos. Os valores de qe obtidos no equilibrio foram de 12,49; 14,06 e 18,06 Êg g-1, respectivamente, na adsorcao do B[k]F, B[a]P e B[b]F pelo MCM-41 e de 22,51; 27,24 e 26,58 Êg g-1, respectivamente, na adsorcao dos mesmos pelo PABA-MCM-41. Os dados cineticos experimentais se ajustaram melhor ao modelo cinetico de pseudo-segunda ordem e o modelo de isoterma de Langmuir descreveu melhor o processo de adsorcao dos HPAs pelo MCM-41 e PABA-MCM-41. Foi verificado que em temperaturas mais altas houve um aumento na taxa inicial de adsorcao e na constante cinetica de adsorcao dos HPAs pelo PABA-MCM-41. Os parametros termodinamicos indicaram que o processo e espontaneo, endotermico e com uma tendencia para desordem do sistema na interface adsorvente/adsorbato. Com a funcionalizacao do MCM-41 foi verificado um aumento na eficiencia de adsorcao dos HPAs de 44,5; 48,4 e 32,0 %, respectivamente para o B[k]F, B[a]P e B[b]F.

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / CdTe semiconductor nanoparticles have unique optical properties, which can be tunable sizes, due to the quantum confinement effect. In the present work, stable CdTe nanocrystals were grown in the mesoporous environment of thiol-functionalized MCM-41 mesoporous silica from an approach employing 3-mercaptopropionic acid, an efficient capping agent. The obtained materials were characterized by infrared spectroscopy, N2 dessortion/adsorption, UV-Vis emission and absorption spectroscopy, transmission electron microscopy (TEM) and electrochemical characterization; X-ray diffraction (XRD) and thermogravimetric analyses were used to MCM-41 silica. The emission properties of CdTe were found to be dependent on the proportion of mesoporous matrix used in the synthesis, yielding CdTe nanocrystals emitting below the wavelength range usually obtained from aqueous colloidal synthesis. The detection of Cu2+ ions using modified carbon paste electrodes by anodic stripping voltammetry was possible only with samples of CdTe in situ, evidencing the role of the semiconductor as active phase. The most active sample obtained here was exactly that containing the lowest CdTe loading, showing it is possible to reduce the dosage of Cd-containing nanocrystals while improving their properties, which is crucial to concretize applications of CdTe nanocrystals. / Nanopartículas semicondutoras de CdTe possuem propriedades ópticas únicas ajustáveis, que são dependentes de seus tamanhos, devido ao efeito do confinamento quântico. No presente trabalho, nanopartículas estáveis de CdTe foram sintetizadas confinadas em um ambiente mesoporoso de uma sílica MCM-41 funcionalizada com grupos tióis, através do método de funcionalização com o uso do ácido 3-mercaptopropiônico. Os materiais obtidos foram caracterizados por espectroscopia vibracional na região do infravermelho, adsorção/dessorção de nitrogênio, espectroscopias eletrônicas de absorção UV-Vis e emissão, microscopia eletrônica de transmissão (MET) e caracterização eletroquímica; já as caracterizações por difração de raios X (DRX) e análise termogravimétrica foram usadas para sílica MCM-41. As propriedades de emissão do CdTe mostraram relação de dependência da proporção da matriz mesoporosa usada nas sínteses, resultando em emissão abaixo da faixa de comprimento de onda usualmente obtido para CdTe em meio coloidal aquoso. A detecção de íons Cu2+ através de eletrodos de pasta de carbono modificados foi realizada por voltametria de redissolução anódica, a qual apresentou sinal somente para as amostras de CdTe in situ, o que evidenciou o papel do semicondutor como fase ativa do eletrodo. A amostra mais ativa foi aquela que continha a menor proporção CdTe, evidenciando que é possível reduzir a dosagem de Cd2+ nos nanocristais enquanto se aperfeiçoam suas propriedades, o que é crucial do ponto de vista das aplicações de nanocristais de CdTe.

Doctor Educationis / The research focused on the synthesis, characterisation and activity of zeolite supported metal catalysts for the Friedel-Crafts alkylation of benzene with t-butyl chloride. Alkyl benzenes are traditionally produced via systems that employ the use of Lewis acids or strong mineral acids. There have been widespread concerns over these approaches based on their environmental impacts and separation difficulties. Recent approaches have endeavoured the much to use more environmentally eco-friendly systems and zeolites have proved to be versatile support materials. The use of zeolites has also shown to greatly improve product selectivity as well as easing separation constraints. However the adoption of zeolites on large scale Friedel-Crafts alkylation has been hampered by the high cost of zeolite production from commercial sources. On the other hand fly ash has been found to be a viable starting material for zeolite synthesis. Apart from that South Africa is faced with fly disposal challenges and there is continual accumulation of fly ash at the coal fired power stations, which provide about 77 % of the power produced in the country. In this light the use of fly ash will help to reduce the disposal constraints as well as providing a cheap starting material for zeolite synthesis. In this study the hierarchical Zeolite X has been successfully synthesised from fly ash via a hydrothermal treatment. The zeolite was then loaded with Fe/Mn via two approaches namely liquid phase ion exchange and incipient wetness impregnation. For comparison purposes seasoned commercial support materials namely HBEA and MCM- 41 were also loaded with the same metals and characterised with various techniques namely; HRSEM, EDS, HRTEM, XRD, SAED, ICP-OES and N2 adsorption analysis, It was found from the characterisation undertaken that the integrity of the respective supports was generally retained upon metal loading. Both the ICP-OES and the EDS proved that the desired metals were successfully introduced onto the zeolitic support materials. The calculated percentage metal loading for the catalysts prepared via incipient wetness impregnation was closely related to the actual values obtained from the ICP-OES analysis for both the monometallic and the bimetallic catalysts (Fe/Mn). It was observed that the amount of metal that can be introduced on a zeolite via liquid phase ion exchange is largely dependent on the cation exchange capacity of the zeolite Supported metal catalysts for FC alkylation Page v and of the catalysts prepared using 0.25 M Fe solution it was found that Zeolite X had the highest Fe wt% loading of 11.4 %, with the lowest loading of 2.2 % obtained with the MCM-41 supported catalyst. The XRD patterns for the both HBEA and the MCM-41 supported metal catalysts resembled the patterns of the respective prestine support materials except in the case of catalysts with anFe wt % of more than 10, which exhibited peaks due to the Fe2O3 crystallites. In the case of the hierarchical Zeolite X, the metal loaded support had a significant reduction in the XRD peak intensities. The prepared catalysts were tested for the alkylation of benzene with t-butyl chloride. The benzene was also used as the solvent. The alkylation reaction was carried out in a round bottomed flask under reflux conditions and stirring at a temperature of 45 oC over a period of 5 h. A total of 18 catalysts was tested and the highest percentage conversion of 100 % was obtained with the 10%FeH after a reaction time of 2 h. The general trend obtained with the majority of the catalysts was characterised with a rapid initial increase and then steady state was achieved. Generally after a reaction time of 3 h almost all the catalysts had reached steady state in terms of the percentage conversion obtained. The outcomes reflect that the inclusion of Mn does not enhance the conversion but rather decreases it. It was also found that the Mn was not active in the alkylation of benzene as shown by the inactivity of the 10%MnM, where 10% by weight Mn was loaded on MCM-41. However the other monometallic catalysts containing Mn supported on Zeolite X and HBEA were found to be active. The activity is attributed to the presence of Brønsted acid sites in these zeolites which are not present in MCM-41. The selectivity studies reflect that the inclusion of Mn does slightly improve the selectivity towards the formation of the monoalkylated product (t-butyl benzene). The highest selectivity of 91.1 % was obtained with the 10%FeMnM after a reaction time of 4 h. MCM-41 supported catalysts had a relatively higher selectivity compared to the other supports. Considering the Fe monometallic catalysts tested it generally can be said that the yield were in the order HBEA > MCM-41 > Zeolite X. It however should be noted that the percentage yield is calculated from the conversion and selectivity percentages, this implies that the factors affecting these parameters will consequently affect the percentage yield obtained. Supported metal catalysts for FC alkylation Page vi The alkylation reaction was found to be characterised by the formation of two intermediate products which could not be identified. These products were formed during the transient start up stages of the reaction and would disappear from the reaction mixture with longer reaction times, and after 3 h in almost all the reactions studied the intermediates were not detected in the reaction mixture. The main products found were the monoalkylated product (desired product) and the para isomer (1,4-t-di-butyl benzene). There were no other dialkylated isomers or trialkylated products detected. The formation of the para isomer was usually after a reaction time of 2 h in most reactions. The research managed to show that the hierarchical Zeolites X can be synthesised from fly ash and ion exchange and incipient wetness impregnation are appropriate approaches that can be used to introduce Fe/Mn onto the support materials studied. The catalysts prepared were active to varying degrees in the Friedel-Crafts alkylation of benzene with t-butylchloride, with the exception of the 10%MnM which was found to be inactive.

Im Rahmen dieser Diplomarbeit sollten die Moeglichkeiten einer kationisch initiierten Polymerisation im Zeolithkanal ueberprueft werden.

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