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@ARTICLE{Carvalho:21146,
      author       = {Carvalho, T. and Augusto, T. and Bras, A.R. and Lourenco,
                      N.M.T. and Afonso, C.A.M. and Barreiros, S. and Correia,
                      N.T. and Vidinha, P. and Cabrita, E.J. and Dias, C.J. and
                      Dionisio, M. and Roling, B.},
      title        = {{U}nderstanding the {I}on {J}elly {C}onductivity
                      {M}echanism},
      journal      = {The journal of physical chemistry / B},
      volume       = {116},
      issn         = {1520-6106},
      address      = {Washington, DC},
      publisher    = {Soc.},
      reportid     = {PreJuSER-21146},
      pages        = {2664 - 2676},
      year         = {2012},
      note         = {We thank the financial support to the Fundacaopara a
                      Ciencia e Tecnologia (Portugal) through projects
                      PTDC/CTM/100244/2008 and PTDC/QUI-QUI/098892/2008. T.C. and
                      V. A., respectively, acknowledge the Ph.D. grants
                      SFRH/BD/47088/2008 and SFRH/BD/42322/2007; P.V. acknowledges
                      the postdoc grant SFRH/BPD/41546/2007. The NMR spectrometers
                      are part of the National NMR Network (RNRMN) and are funded
                      by Fundacao para a Ciencia e Tecnologia.},
      abstract     = {The properties of the light flexible device, ion jelly,
                      which combines gelatin with an ionic liquid (IL) were
                      recently reported being promising to develop safe and highly
                      conductive electrolytes. This article aims for the
                      understanding of the ion jelly conductive mechanism using
                      dielectric relaxation spectroscopy (DRS) in the frequency
                      range 10(-1)-10(6) Hz; the study was complemented with
                      differential scanning calorimetry (DSC) and pulsed field
                      gradient nuclear magnetic resonance (PFG NMR) spectroscopy.
                      The room temperature ionic liquid
                      1-butyl-3-methylimmidazolium dicyanamide (BMIMDCA) used as
                      received $(1.9\%$ w/w water content) and with $6.6\%$ (w/w)
                      of water content and two ion jellies with two different
                      ratios BMIMDCA/gelatin/water $\%$ (w/w), IJ1
                      (41.1/46.7/12.2) and IJ3 (67.8/25.6/6.6), have been
                      characterized. A glass transition was detected by DSC for
                      all materials allowing for classifying them as glass
                      formers. For the ionic liquid, it was observed that the
                      glass transition temperature decreases with the increase of
                      water content. While in subsequent calorimetric runs
                      crystallization was observed for BMIMDCA with negligible
                      water content, no crystallization was detected for any of
                      the ion jelly materials upon themal cycling. To the
                      dielectric spectra of all tested materials, both dipolar
                      relaxation and conductivity contribute; at the lowest
                      frequencies, electrode and interfacial polarization highly
                      dominate. Conductivity, which manifests much more intensity
                      relative to dipolar reorientations, strongly evidences
                      subdiffusive ion dynamics at high frequencies. From
                      dielectric measures, transport properties as mobility and
                      diffusion coefficients were extracted. Data treatment was
                      carried out in order to deconvolute the average diffusion
                      coefficients estimated from dielectric data in its
                      individual contributions of cations (D(+)) and anions
                      (D(-)). The D(+) values thus obtained for IJ3, the ion jelly
                      with the highest IL/gelatin ratio, cover a large temperature
                      range up to room temperature and revealed excellent
                      agreement with direct measurements from PFG NMR, obeying to
                      the same VFT equation. For $BMIMDCA(6.6\%water),$ which has
                      the same water amount as IJ3, the diffusion coefficients
                      were only estimated from DRS measurements over a limited
                      temperature range; however, a single VFT equation describes
                      both DRS and PFG NMR data. Moreover, it was found that the
                      diffusion coefficients and mobility are similar for the
                      ionic liquid and IJ3, which points to a role of both water
                      and gelatin weakening the contact ion pair, facilitating the
                      translational motion of ions and promoting its dissociation;
                      nevertheless, it is conceivable the existence of a critical
                      composition of gelatin that leads to those properties. The
                      VFT temperature dependence observed for the conductivity was
                      found to be determined by a similar dependence of the
                      mobility. Both conductivity and segmental motion revealed to
                      be correlated as inferred by the relatively low values of
                      the decoupling indexes. The obtained results show that ion
                      jelly could be in fact a very promising material to design
                      novel electrolytes for different electrochemical devices,
                      having a performance close to the IL but presenting an
                      additional stability regarding electrical measurements and
                      resistance against crystallization relative to the bulk
                      ionic liquid.},
      keywords     = {Calorimetry, Differential Scanning / Electric Conductivity
                      / Ions / Magnetic Resonance Spectroscopy / Ions (NLM
                      Chemicals) / J (WoSType)},
      cin          = {ICS-1 / JCNS-1},
      ddc          = {530},
      cid          = {I:(DE-Juel1)ICS-1-20110106 / I:(DE-Juel1)JCNS-1-20110106},
      pnm          = {BioSoft: Makromolekulare Systeme und biologische
                      Informationsverarbeitung (FUEK505) / 544 - In-house Research
                      with PNI (POF2-544)},
      pid          = {G:(DE-Juel1)FUEK505 / G:(DE-HGF)POF2-544},
      shelfmark    = {Chemistry, Physical},
      typ          = {PUB:(DE-HGF)16},
      pubmed       = {pmid:22369088},
      UT           = {WOS:000301169300004},
      doi          = {10.1021/jp2108768},
      url          = {https://juser.fz-juelich.de/record/21146},
}