Avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso MCM-48

The control of the pore geometry and diameter of the mesoporous materials based on silica is necessary for the greater applicability of these materials, especially in processes dependent on the shape selectivity. In this sense, several studies have dedicated efforts to the greater control of the str...

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Autor principal: Ribeiro, Simone Oliveira
Outros Autores: Melo, Dulce Maria de Araújo
Formato: bachelorThesis
Idioma:pt_BR
Publicado em: Universidade Federal do Rio Grande do Norte
Assuntos:
Peneiras moleculares. Sílica mesoporosa. MCM-48. Surfactantes. Cadeia hidrofóbica. Diâmetro de poros
Mesoporous silica. MCM-48. Surfactants. Hydrophobic chain. Diameter of pores
Endereço do item:https://repositorio.ufrn.br/handle/123456789/38204
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id ri-123456789-38204
record_format dspace
institution Repositório Institucional
collection RI - UFRN
language pt_BR
topic Peneiras moleculares. Sílica mesoporosa. MCM-48. Surfactantes. Cadeia hidrofóbica. Diâmetro de poros
Mesoporous silica. MCM-48. Surfactants. Hydrophobic chain. Diameter of pores
spellingShingle Peneiras moleculares. Sílica mesoporosa. MCM-48. Surfactantes. Cadeia hidrofóbica. Diâmetro de poros
Mesoporous silica. MCM-48. Surfactants. Hydrophobic chain. Diameter of pores
Ribeiro, Simone Oliveira
Avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso MCM-48
description The control of the pore geometry and diameter of the mesoporous materials based on silica is necessary for the greater applicability of these materials, especially in processes dependent on the shape selectivity. In this sense, several studies have dedicated efforts to the greater control of the structure of these materials. Samples of MCM-48 molecular sieves having different pore sizes were prepared starting from a gel having the following molar composition: 1 SiO2 – 0,25 NaOH – 0,4 (CnH2n-1N(CH3)3Br – 100 H2O. The pore diameter of the samples was controlled by varying the hydrocarbon chain length of the surfactant. In this study the influence of surfactants with different hydrophobic tail lengths (alkyltrimethylammonium, CnH2n-1N(CH3)3Br , n = 17-21) on the formation and properties of mesoporous silicas was verified. The samples were characterized by X-ray diffraction (XRD), thermal analysis (TG / DTG), infrared spectroscopy (FT-IR) and adsorption and physical desorption of N2 (BET). It was observed a relation between the chain size and the pore diameter was observed and inversely proportional to the structural ordering. Furthermore, it is observed that as silicas synthesized with a mixture of the surfactants resulted in materials with a high surface area, main pore diameters and structural ordering. As analysis by N2 physisorption revealed that emerging material from specific surface areas in the range of 703 to 1069 m2 g-1 for samples synthesized by blends being a more expressive C17C19C21 (1069 m2 g-1) blend. From the XRD analysis it was observed that as mixtures of surfactants they assigned as samples a better cubic organization of the pores and a narrow distribution of comparisons as synonyms synthesized with only one of the surfactants.
author2 Melo, Dulce Maria de Araújo
author_facet Melo, Dulce Maria de Araújo
Ribeiro, Simone Oliveira
format bachelorThesis
author Ribeiro, Simone Oliveira
author_sort Ribeiro, Simone Oliveira
title Avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso MCM-48
title_short Avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso MCM-48
title_full Avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso MCM-48
title_fullStr Avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso MCM-48
title_full_unstemmed Avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso MCM-48
title_sort avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso mcm-48
publisher Universidade Federal do Rio Grande do Norte
publishDate 2018
url https://repositorio.ufrn.br/handle/123456789/38204
work_keys_str_mv AT ribeirosimoneoliveira avaliacaodousodediferentessurfactantescationicosnasintesedomaterialmesoporosomcm48
_version_ 1773959832008654848
spelling ri-123456789-382042023-05-30T16:02:56Z Avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso MCM-48 Ribeiro, Simone Oliveira Melo, Dulce Maria de Araújo Costa, Cíntia de Castro Medeiros, Rodolfo Luiz Bezerra de Araújo Peneiras moleculares. Sílica mesoporosa. MCM-48. Surfactantes. Cadeia hidrofóbica. Diâmetro de poros Mesoporous silica. MCM-48. Surfactants. Hydrophobic chain. Diameter of pores The control of the pore geometry and diameter of the mesoporous materials based on silica is necessary for the greater applicability of these materials, especially in processes dependent on the shape selectivity. In this sense, several studies have dedicated efforts to the greater control of the structure of these materials. Samples of MCM-48 molecular sieves having different pore sizes were prepared starting from a gel having the following molar composition: 1 SiO2 – 0,25 NaOH – 0,4 (CnH2n-1N(CH3)3Br – 100 H2O. The pore diameter of the samples was controlled by varying the hydrocarbon chain length of the surfactant. In this study the influence of surfactants with different hydrophobic tail lengths (alkyltrimethylammonium, CnH2n-1N(CH3)3Br , n = 17-21) on the formation and properties of mesoporous silicas was verified. The samples were characterized by X-ray diffraction (XRD), thermal analysis (TG / DTG), infrared spectroscopy (FT-IR) and adsorption and physical desorption of N2 (BET). It was observed a relation between the chain size and the pore diameter was observed and inversely proportional to the structural ordering. Furthermore, it is observed that as silicas synthesized with a mixture of the surfactants resulted in materials with a high surface area, main pore diameters and structural ordering. As analysis by N2 physisorption revealed that emerging material from specific surface areas in the range of 703 to 1069 m2 g-1 for samples synthesized by blends being a more expressive C17C19C21 (1069 m2 g-1) blend. From the XRD analysis it was observed that as mixtures of surfactants they assigned as samples a better cubic organization of the pores and a narrow distribution of comparisons as synonyms synthesized with only one of the surfactants. O controle da geometria e do diâmetro dos poros dos materiais mesoporosos à base de sílica faz-se necessário para a maior aplicabilidade destes materiais, principalmente em processos dependentes da seletividade de forma. Neste sentido, diversos estudos têm dedicado esforços para o maior controle da estrutura destes materiais. Amostras de peneira molecular MCM-48 apresentando diferentes tamanhos de poros foram preparadas partindo-se de um gel com a seguinte composição molar: 1 SiO2 – 0,25 NaOH – 0,4 (CnH2n-1N(CH3)3Br – 100 H2O. O diâmetro dos poros das amostras foi controlado variando comprimento da cadeia hidrocarbônica do surfactante e utilizando a mistura entre eles. Neste estudo verificou-se a influência de surfactantes com diferentes comprimentos de cauda hidrofóbica (alquiltrimetilamônio, CnH2n-1N(CH3)3Br , n = 17-21) na formação e propriedades de sílicas mesoporosas. As amostras foram caracterizadas através das análises de difração de raios-x (DRX), análise térmica (TG/DTG), espectroscopia na região do infravermelho (FT-IR) e fisissorção de N2 (BET). Observou-se uma relação diretamente proporcional entre o tamanho da cadeia e o diâmetro de poros e inversamente proporcional em relação ao ordenamento estrutural. Além disso, observou-se que as sílicas sintetizadas com a mistura dos surfactantes resultaram em materiais com um elevada área superficial, maior diâmetros de poros e ordenação estrutural. As análises por fisisorção de N2 revelaram que os materiais apresentaram valores de áreas superficiais específicas na faixa de 703 a 1069 m2 g-1 para as amostras sintetizadas pelas misturas sendo a mistura C17C19C21 a mais expressiva (1069 m2 g-1). Pela analise de DRX observou-se que as misturas de surfactantes atribuíram as amostras uma melhor organização cúbica dos poros e uma estreita distribuição de diâmetros comparada as sílicas sintetizadas com apenas um dos surfactantes. 2018-04-19T10:48:06Z 2021-09-27T11:39:13Z 2018-04-19T10:48:06Z 2021-09-27T11:39:13Z 2017-12-15 bachelorThesis 2014021230 RIBEIRO, Simone Oliveira. Avaliação do uso de diferentes surfactantes catiônicos na síntese do material mesoporoso MCM-48. 2017. 59f. Trabalho de Conclusão de Curso (Graduação em Química), Instituto de Química, Universidade Federal do Rio Grande do Norte, Natal, 2017. https://repositorio.ufrn.br/handle/123456789/38204 pt_BR openAccess application/pdf Universidade Federal do Rio Grande do Norte Brasil UFRN Química Bacharelado

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