Utilize este identificador para referenciar este registo:
https://hdl.handle.net/1822/15077
Título: | Di-ureasil hybrids doped with LiBF4 : spectroscopic study of the ionic interactions and hydrogen bonding |
Autor(es): | Fernandes, Mariana Barbosa, P. C. Silva, Maria Manuela Smith, Michael John Zea Bermudez, V. de |
Palavras-chave: | Di-ureasils Lithium tetrafluoroborate FTIR FT-Raman |
Data: | Jun-2011 |
Editora: | Elsevier |
Revista: | Materials Chemistry and Physics |
Resumo(s): | In the present work Fourier Transform infrared and Raman spectroscopy were used to characterize the cation/polymer, cation/cross-link, cation/anion and hydrogen bonding interactions in hybrid electrolytes composed of lithium tetrafluoroborate (LiBF4) and di-urea cross-linked poly(oxyethylene) (POE)/siloxane hybrid networks (di-ureasils) designated as d-(2000) and d-U(600) and incorporating polyether chains with ca. 40.5 and 8.5 oxyethylene repeat units, respectively. Samples with ∞ > n ≥ 2.5 (where n, composition, is the molar ratio of CH2CH2O units per Li+ ion) were analyzed. In both di-ureasil systems over the whole range of salt content examined the Li+ ions bond to the ether oxygen atoms of amorphous POE chains and to BF4- ions forming ion contact pairs. Spectroscopic evidences and SEM images confirm the presence of a crystalline POE/LiBF4 complex of unknown stoichiometry at n < 20 and 25, respectively. Ionic association is particularly important in the case of the d-U(600)-based materials, as a result of the presence of strong hydrogen-bonded aggregates that prevent the establishment of Li+/urea carbonyl oxygen atom interactions. |
Tipo: | Artigo |
URI: | https://hdl.handle.net/1822/15077 |
DOI: | 10.1016/j.matchemphys.2011.04.030 |
ISSN: | 0254-0584 |
Versão da editora: | The original publication is available at www.elsevier.com |
Arbitragem científica: | yes |
Acesso: | Acesso aberto |
Aparece nas coleções: | CDQuim - Artigos (Papers) |
Ficheiros deste registo:
Ficheiro | Descrição | Tamanho | Formato | |
---|---|---|---|---|
MatChemPhys2011.pdf | documento principal | 210,95 kB | Adobe PDF | Ver/Abrir |