Materiais compósitos obtidos a partir da interação com o complexo bimetálico CoCu(opba) em sílicas porosas

• Autor(a) principal: Oliveira, Naiara Raica Lopes de
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Repositório Institucional da UFG
• dARK ID: ark:/38995/001300000f583
• Texto Completo: http://repositorio.bc.ufg.br/tede/handle/tede/5456
• topic: Materiais compósitos; Sílica; Complexos; Composite materials; Sílica; Complex; CIENCIAS EXATAS E DA TERRA::QUIMICA

Composite materials are being widely studied in several areas in order to produce materials with improved properties than to the isolated constituents. There are several matrices and phases that can be used to construct composite materials. In this work, composites were prepared from CoCu(opba)@S (where S = mesoporous silica). The matrices used were mesoporous silica, synthesized in various ways, resulting in silicas with different surface areas, diameter and pore volume. The silicas were prepared by sol-gel method making three changes that led the following silicas S1AMAC, S2 and S3AM. The methodology for the preparation of the composites was wet impregnation of precursor complex (NBu4)2[Cu(opba)], and subsequent in situ reaction with the second metal (CoII) to reach hetero bimetallic complex in the matrices.Structural, optical and magnetic properties were studied by infrared spectroscopy vibrational, Raman spectroscopy, UV-vis spectroscopy, transmission electron microscopy, scanning electron microscopy and magnetic measurements.Spectroscopic characterization confirmed the silica formation and the bimetallic complex inside matrix pores.By microscopy was proved that the complex is inside the pores in the nanometer form.Was observed that the porous silica matrix interfere in the structural organization of the bimetallic complex that is formed within the pores.This influence is confirmed in the magnetic behavior of the bimetallic complex, impregnated in silica, which obtained ferrimagnetic behavior in according to the literature for bimetallic chain [Cocu (opba)] polycrystalline.But it was observed by dynamic susceptibility measurements in phase and out of phase a dependence of the confinement of the complex in the pores of the matrix.