resumo
Due to its elasticity, transparency and biocompatibility, polydimethylsiloxane (PDMS) has been used as an organic component of hybrid materials in different fields of application such as photonics or biomaterials. Typically an acidic medium is used in the sol-gel processing of PDMS-metal oxide systems due to its catalytic effect. Furthermore, when dealing with highly reactive transition metal alkoxides, a chelating agent is pointed out as being necessary to avoid phase separation. In this work a new approach to the preparation procedure of hybrid materials, based on the system PDMS-SiO2-MO2 with M=Ti or Zr, was used. Samples were prepared at different pH values, without water addition and in the presence or absence of a chelating agent (ethyl acetoacetate). All samples were homogeneous and transparent even at high pH. ATR-IR, Si-29-NMR MAS and Si-29-{H-1} CP-MAS were used for the characterization of the obtained samples. According to the 29Si-{H-1} CP-MAS results some differences in the nature of difunctional D ((CH3)(2)center dot SiO2) and tetrafunctional (SiO4) Q structural units were observed. The presence of Ti-O-Si and Zr-O-Si bonds was confirmed by ATR-IR analysis. (C) 2014 Elsevier B.V. All rights reserved.
palavras-chave
POLYDIMETHYLSILOXANE; NANOCOMPOSITES; OXIDE
categoria
Materials Science; Physics
autores
Almeida, JC; Castro, AGB; Salvado, IMM; Margaca, FMA; Fernandes, MHV
nossos autores
Isabel Margarida Miranda Salvado
Professor associado
José Carlos Martins de Almeida
Investigador
Maria Helena Figueira Vaz Fernandes
Professor associadoGrupos
3 - materiais de carbono, compósitos e revestimentos funcionais
5 - materiais biomédicos e biomiméticos
Projectos
Hybrid materials for biomedical applications (PTDC/CTM/101115/2008)
Centre for Research in Ceramics and Composite Materials - CICECO (LA0011: 2013-2014) (PEst-C/CTM/LA0011/2013)
agradecimentos
This work is financed by FEDER funds (Program COMPETE) and by FCT funds, on the project PTDC/CTM/101115/2008 and by the grant SFRH/BD/72074/2010. We also acknowledge the program financed by CICECO, Pest-C/CTM/LA0011/2013.