Encontrados 19 documentos, a visualizar página 1 de 2
Chitosan membranes containing micro or nano-size bioactive glass particles : ev...
Caridade, S. G.; Merino, Esther G.; Alves, N. M.; Zea Bermudez, V. de; Boccaccini, A. R.; Mano, J. F.A newfamilyofbiodegradablepolymer/bioactiveglass(BG)compositematerialshas emergedbasedontheavailabilityofnano-sizedbioactiveparticles.Suchnovelbiocompo- sites canhaveenhancedperformance,intermsofmechanicalpropertiesandbioactivity, and theycanbedesignedtobeusedinboneregenerationapproaches. In thiswork,membranesofchitosan(CTS)andchitosanwithbioactiveglass(BG)both micron andnanosizedparticles(CTS/mBG,CTS/nBG,respe...
Structural studies of novel di-ureasil ormolytes doped with lithium hexafluoroa...
Rodrigues, L. C.; Fernandes, M.; Zea Bermudez, V. de; Silva, Maria Manuela; Smith, Michael JohnHybrid electrolytes produced by the sol-gel process were obtained by doping a di-urea cross-linked POE/siloxane hybrid host framework (d-U(2000)) with lithium hexafluoroantimonate (LiSbF6). Flexible, transparent xerogel films with ∞ > n ≥ 2.5 (where n, composition, represents the molar ratio of oxyethylene units OCH2CH2 per Li+ ion), thermally stable to at least 200 ºC, were prepared. At 30 ºC the highest ionic...
K+-doped poly(gamma-caprolactone)/siloxane biohybrid electrolytes for electroch...
Fernandes, M.; Rodrigues, L. C.; Ferreira, R. A. Sá; Gonçalves, A.; Fortunato, E.; Silva, Maria Manuela; Smith, Michael John; Zea Bermudez, V. deIn Press; available online 10 November 2011 ; Sol-gel derived KCF3SO3-doped di-urethane cross-linked poly(ε-caprolactone) (PCL(530))/siloxane ormolytes with ∞ > n ≥ 0.5 (n indicates the number of (C(=O)(CH2)5O) repeat units per K+ ion) have been studied. Xerogel samples with n ≥ 1 are thermally stable up to 235 ºC. A minor proportion of PCL crystallites occur in some dilute-to-concentrated samples. At n ≤ 4 a ...
Di-ureasil hybrids doped with LiBF4 : attractive candidates as electrolytes for...
Barbosa, P. C.; Fernandes, M.; Silva, Maria Manuela; Smith, Michael John; Vilela, Sérgio M. F.; Gonçalves, A.; Olveira, M. C.; Fortunato, E.; Rego, R.The sol-gel process has been used to prepare hybrid electrolytes composed of a poly(oxyethylene) (POE)/siloxane hybrid network doped with lithium tetrafluoroborate (LiBF4) with compositions of n between ∞ and 2.5. In this context the lithium salt concentration is expressed in terms of the number of oxyethylene units in the organic component of the network per Li+ ion. Electrolyte samples with n ≥ 20 are thermal...
Di-ureasil hybrids doped with LiBF4 : spectroscopic study of the ionic interact...
Fernandes, Mariana; Barbosa, P. C.; Silva, Maria Manuela; Smith, Michael John; Zea Bermudez, V. deIn 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...
Mg2+-doped poly(ε-caprolactone)/siloxane biohybrids
Teixeira, J. C. S.; Fernandes, M.; Zea Bermudez, V. de; Barbosa, P. C.; Rodrigues, L. C.; Silva, Maria Manuela; Smith, Michael JohnElectrolytes based on a poly(ε-caprolactone) (PCL)/siloxane organic/inorganic host framework doped with magnesium triflate (Mg(CF3SO3)2) were synthesized by the sol-gel process. In the biohybrid matrix short PCL chains are covalently bonded via urethane linkages to the siliceous network. In this study the salt content of samples was identified using the conventional n notation, where n indicates the number of (...
Structure, thermal properties, conductivity and electrochemical stability of di...
Gonçalves, M. C.; Zea Bermudez, V. de; Silva, Maria Manuela; Smith, Michael John; Morales, Enrique; Ferreira, R. A. Sá; Carlos, L. D.Variable chain length di-urethane cross-linked poly(oxyethylene) (POE)/siloxane hybrid networks were prepared by application of a sol-gel strategy. These materials, designated as di-urethanesils (represented as d-Ut(Y’), where Y’ indicates the average molecular weight of the polymer segment), were doped with lithium triflate (LiCF3SO3). The two host hybrid matrices used, d-Ut(300) and d-Ut(600), incorporate POE...
Di-ureasil xerogels containing lithium triflate for application in solid state ...
Barbosa, P. C.; Silva, Maria Manuela; Smith, Michael John; Gonçalves, A.; Fortunato, E.; Zea Bermudez, V. de; Nunes, SílviaDocumento submetido para revisão pelos pares. A publicar em Electrochimica Acta. ISSN 0013-4686. ; In this study we report the characterization of a solid-state electrochromic device based on poly(ethylene oxide) (PEO)/siloxane hybrid networks doped with lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). The polymer networks prepared, classed as di-ureasils and represented by d-U(2000), were produced by the ...
Structure and photoluminescence of di-amidosil nanohybrids incorporating europi...
Nunes, Sílvia; Zea Bermudez, V. de; Cybinska, J.; Ferreira, R. A. Sá; Carlos, Luís; Legedziewicz, J.; Silva, Maria Manuela; Smith, Michael JohnThe sol–gel process was used to prepare amorphous di-amide cross-linked alkyl/siloxane hybrid materials (di-amidosils) incorporating europium triflate (Eu(CF3SO3)3). Samples with 200 ≤ n ≤ 8 (where n is the molar ratio of carbonyl oxygen atoms per Eu3+ ion) were studied. The conformations of the alkyl chains of the host matrix in the doped di-amidosils (essentially gauche) are not affected by the presence of th...
Cation coordination and hydrogen bonding in potassium and magnesium-based di-am...
Nunes, Sílvia; Zea Bermudez, V. de; Ostrovskii, David; Carlos, Luís; Silva, Maria Manuela; Smith, Michael JohnFourier transform mid-infrared and Raman spectroscopies were employed to elucidate the cation/ alkylene chains, cation/cross-link, cation/anion interactions and hydrogen bonding occurring in amorphous di-amide cross-linked alkylene/siloxane hybrid materials (di-amidosils) doped with potassium and magnesium triflates (KCF3SO3 and Mg(CF3SO3)2, respectively). Materials with compositions oo > n > 5 (where n express...
| Financiadores do RCAAP | |||||||
|
|
|
|
|
|
||