Materials hierarchically structuralized with mesoporosa cubical phase: synthesis, characterization and use as support in the immobilization of enzyme HRP / Materiais hierarquicamente estruturados com fase cúbica mesoporosa: síntese, caracterização e uso como suporte na imobilização da enzima HRP

AUTOR(ES)
DATA DE PUBLICAÇÃO

2009

RESUMO

Hierarchical silica porous materials have been successfully synthesized using polystyrene nanospheres as macropore template, triblock copolymer Pluronic F127 as mesopore template, tetramethyl orthosilicate as silica source and ethanol as cosurfactant. The obtained materials were characterized by XRD, TG-DTA, N2 adsorption, Hg porosimetry, SEM, HRSEM, TEM and AFM. These materials consist of a system of macropores with diameters of ca. 300 nm whose walls are filled with mesoporous material with an average pore of diameter 10 nm. The materials are also integrated with non-crystalline micropores. The synthesized hierarchical materials have been obtained both as powder and as monoliths, which shows that this material can be generated according to specific necessities. The XRD pattern indicates one sample with structure Fm3 m, which consists of the mesopores organized in a face-centred cubic arrangement. High-resolution scanning electron microscopic analyses revealed silica forming envelope-like structure around the polystyrene nanospheres, giving rise to other macroporous sites. This fact implies the formation of channel systems in which two macropores types co-exist. The hierarchical porous materials exhibited a BET surface area up to 469 m2 g-1, and macroporous area of 55 m2 g-1. The synthesized materials have also been suitable as support for enzyme immobilization (HRP horseradish peroxidase). However, problems possibly related to the high complexity within the materials affected the biocatalyst activity

ASSUNTO(S)

mesoporosidade porous silica materials peroxidase macroporosity imobilização enzimática enzyme immobilization peroxidase mesoporosity hierarchical porous materials materiais hierarquicamente estruturados macroporosidade quimica bio-inorganica materiais porosos

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