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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Obtaining of nanobiocatalysts through the immobilization of calb in superparamagnetics nanoparticles / ObtenÃÃo de nanobiocatalisadores atravÃs da imobilizaÃÃo de calb em nanopartÃculas superparamagnÃticas

Victor Moreira da Costa 05 February 2014 (has links)
CoordenaÃÃo de AperfeiÃoamento de NÃvel Superior / The magnetic nanomaterials have attracted interest in many areas due to their unique properties and a wide range of applications. One of the most used nanoparticles is magnetite, formed of an oxide of Fe +2 and Fe +3 which has a high saturation magnetization and high surface area. These properties allow the immobilization of various molecules , such as surfactants , co - polymers , drugs and enzymes for application in biomedicine , food engineering , nanochips and biocatalysts . In the present work nanobiocatalysts were produced by immobilization of CALB (Lipase B) in superparamagnetic nanoparticles functionalized with different concentrations of APTES. The structural, morphological and magnetic properties of the samples were investigated by X- ray diffraction (XRD), Spectroscopy with Fourier Transform Infrared in Region (FTIR), Thermogravimetric Analysis (TGA), adsorption/desorption of nitrogen (BET), Magnetometer Sample Vibrant (VSM), and Analysis of Catalytic Activity (Activity derivative). The XRD showed peaks crystallographic structure of spinel for magnetite in the sample. The average particle size obtained by XRD and VSM was 10nm for magnetite and 13nm for NP/ APTES. The magnetic parameters of the samples were observed by VSM and all showed superparamagnetic behavior with a decrease in the saturation magnetization of 69 emu / g of magnetite to about 35 emu / g for the complete system . TG analyzes and FTIR revealed the presence of molecules of APTES on the surface of the nanoparticle in which were found the best values of adsorption for sample NP / APTES (1:3) and this used for the immobilization of the enzyme. Was performed analysis of the hydrolytic activity of the immobilized enzyme prepared in different media concentrations of APTES. Which showed a maximum activity of 47 U / g for NP/APTES (1:3)/CALB(200). Therefore, the potential presented nanobiocatalysts formed in reactions of industrial interest. / Os nanomateriais magnÃticos tÃm atraÃdo o interesse em muitas Ãreas, devido Ãs suas propriedades Ãnicas e uma vasta gama de aplicaÃÃes. Uma das nanopartÃculas mais utilizadas à a magnetita, formada por um Ãxido de Fe+2 e Fe+3 que tem uma alta magnetizaÃÃo de saturaÃÃo e elevada Ãrea superficial. Tais propriedades permitem a imobilizaÃÃo de vÃrias molÃculas, tais como surfactantes, co-polÃmeros, drogas e enzimas para a aplicaÃÃo no campo da biomedicina, engenharia de alimentos, nanochips e biocatalizadores. No presente trabalho foram produzidos nanobiocatalisadores atravÃs da imobilizaÃÃo de CALB(Lipase B) em nanopartÃculas superparamagnÃticas funcionalizadas com diferentes concetraÃÃes de APTES. As propriedades estruturais, magnÃticas e morfologicas das amostras foram investigadas por DifraÃÃo de Raios-X (DRX), Espectroscopia na RegiÃo do Infravermelho com Transformada de Fourier (FTIR), AnÃlise TermogravimÃtrica (TGA), AdsorÃÃo/DessorÃÃo de NitrogÃnio (BET), MagnetÃmetro de Amostra Vibrante (VSM) e AnÃlise da Atividade CatalÃtica (Atividade do Derivado). O DRX mostrou picos cristalogrÃficos da estrutura de espinÃlio para a amostra de magnetita. O tamanho mÃdio das partÃculas obtidas atravÃs de DRX e VSM foi de 10nm para magnetita, 13nm para NP/APTES/CALB. Os parÃmetros magnÃticos das amostras foram observados por VSM e todos apresentaram comportamentos superparamagnÃticos com uma diminuiÃÃo na magnetizaÃÃo de saturaÃÃo de 69 emu/g da magnetita para aproximadamente 35 emu/g para o sistema completo. As anÃlises de TG e FTIR evidenciaram a presenÃa de molÃculas de APTES na superfÃcie da nanopartÃcula na qual foram encontrados melhores valores de adsorÃÃo para a amostra NP/APTES (1:3), sendo essa utilizada para a imobilizaÃÃo da enzima. Foi realizada a anÃlise de atividade hidrolÃtica da enzima imobilizada nos diferentes suportes preparados com concentraÃÃes de APTES. A qual demonstrou uma mÃxima atividade de 47 U/g para NP/APTES(1:3)/CALB(200). Por isso, o nanobiocatalisador formado apresenta potencial em reaÃÃes de interesse industrial.

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