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Vibrational analysis of d-PCL(530)/siloxane based hybrids doped with two lithiu...
Ferreira, C. B.; Fernandes, M.; Rodrigues, L. C.; Silva, Maria Manuela; Smith, Michael John; Bermudez, V. de ZeaPublished online: 22 May 2013 ; The present study has been focused on environmentally friendly sol-gel derived electrolytes based on a di-urethane cross-linked d-PCL(530)/siloxane network (where d represents di, PCL identifies the poly(ε–caprolactone) biopolymer and 530 is the average molecular weight in g.mol-1) doped with a wide range of concentration of lithium perchlorate (LiClO4) and lithium bis(trifluoro...
Poly(ε-caprolactone)/siloxane biohybrids with applications in "smart windows"
Rodrigues, L. C.; Silva, Maria Manuela; Smith, Michael John; Gonçalves, A.; Fortunato, E.In view of the potential technological impact of solid polymer electrolytes (SPEs) in the domain of solid-state electrochemistry, particularly in the production of advanced batteries, sensors and electrochromic and photoelectrochemical devices, the sub-class of SPE materials has attracted considerable interest during the last two decades. Li+-doped ormolyte systems obtained using the sol-gel method has been inv...
Synthesis and electrochemical characterization of aPEO-based polymer electrolyte
Rodrigues, Luísa; Silva, Maria Manuela; Veiga, H.; Esperança, J.; Costa, M.; Smith, Michael JohnIn this paper the preparation and purification of an amorphous polymer network, poly[oxymethylene-oligo(oxyethylene)], designated as aPEO, are described. The flexible CH2CH2O segments in this host polymer combine appropriate mechanical properties, over a critical temperature range from -20 to 60 ºC, with labile salt-host interactions. The intensity of these interactions is sufficient to permit solubilization of...
Synthesis and characterization of amorphous poly(ethylene oxide)/poly(trimethyl...
Rodrigues, Luísa; Silva, Maria Manuela; Smith, Michael JohnSolid Polymer Electrolytes (SPEs) have been proposed as substitutes for conventional non-aqueous electrolytes in various electrochemical devices. These promising materials may be of interest in various practical devices including batteries, sensors and electrochromic displays as they can offer high performance in terms of specific energy and specific power (batteries), safe operation, form flexibility in device...
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 ...
Characterization of polyether-poly(methyl methacrylate)-lithium perchlorate ble...
Barbosa, P. C.; Rodrigues, L. C.; Silva, Maria Manuela; Smith, Michael John; Valente, Prudência B.; Gonçalves, A.; Fortunato, E.Em publicação ; Solid polymer electrolytes (SPEs) systems based on interpenetrating blends of poly(ethylene oxide-co-propylene oxide) and poly(methyl methacrylate) host matrices, with lithium perchlorate as guest salt, were prepared. These electrolytes were presented as free-standing films, and their thermal and electrochemical properties were characterized by conductivity and electrochemical stability measure...
Characterization of pTMCnLiPF6 solid polymer electrolytes
Barbosa, P. C.; Rodrigues, L. C.; Silva, Maria Manuela; Smith, Michael JohnIn this study the results our characterization of a solid polymer electrolyte based on poly(trimethylene carbonate), henceforth designated as p(TMC), and lithium hexafluorophosphate (LiPF6) are described. Samples of solvent-free electrolytes were prepared with a range of concentration of guest salt using solvent casting from tetrahydrofuran and characterized by conductivity measurements, thermal analysis and el...
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...
Preliminary characterization of pTMCnLiAsF6 hybrid polymer electrolytes for ele...
Rodrigues, L. C.; Silva, Maria Manuela; Smith, Michael John; Gonçalves, A.; Fortunato, E.In this exploratory study the results of characterisation of a poly(oxyethylene) (PEO)/siloxane hybrid network electrolyte doped with lithium hexafluoroarsenate (LiAsF6) are described. In accordance with convention, the lithium salt concentration is expressed in terms of the number of oxyethylene units in the organic component of the host network per Li+ ion guest species. Samples of solvent-free electrolytes w...
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