Effect of presence of an acid catalyst on structure and properties of iron-doped siloxane-polyoxyethylene nanocomposites prepared by sol-gel

Nenhuma Miniatura disponível

Data

2004-10-15

Orientador

Coorientador

Pós-graduação

Curso de graduação

Título da Revista

ISSN da Revista

Título de Volume

Editor

Elsevier B.V.

Tipo

Artigo

Direito de acesso

Acesso restrito

Resumo

In this work we investigate the effect of hydrochloric acid (HC) addition on the structure and thermal and magnetic properties of iron-doped siloxane-polyoxyethylene (POE) hybrids prepared by the sol-gel route. X-ray powder diffraction (XRD) and X-ray absorption near edge structure (XANES) results reveal the dominance of ferrihydrite nanoparticles and a mixture of this phase with FeCl4- species in the hybrid prepared without and with HCl, respectively. Thermal analysis reveals the existence of two crystalline polymeric phases in the hybrid prepared with HCl whereas hybrids prepared without HCl are amorphous. The 105 and 60 Angstrom sized ferrihydrite nanoparticles were detected by SAXS analysis of the composite prepared without and with HCl, respectively. The magnetic results suggest that in both samples antiferromagnetic nanoparticles coexist with small clusters/isolated ions. In the sample without HCl addition, larger particles dominate the magnetic behavior, while the opposite occurs for the sample prepared using HCl catalyst. (C) 2004 Elsevier B.V. All rights reserved.

Descrição

Palavras-chave

Idioma

Inglês

Como citar

Journal of Non-crystalline Solids. Amsterdam: Elsevier B.V., v. 345, p. 585-590, 2004.

Itens relacionados

Financiadores