dc.creator | Pawlicka, Agnieszka | |
dc.creator | Mattos, R. I. | |
dc.creator | Tambelli, Caio Eduardo de Campos | |
dc.creator | Silva, I. D. A | |
dc.creator | Magon, Claudio José | |
dc.creator | Donoso, José Pedro | |
dc.date.accessioned | 2014-06-25T19:29:04Z | |
dc.date.accessioned | 2018-07-04T16:46:13Z | |
dc.date.available | 2014-06-25T19:29:04Z | |
dc.date.available | 2018-07-04T16:46:13Z | |
dc.date.created | 2014-06-25T19:29:04Z | |
dc.date.issued | 2013-02 | |
dc.identifier | Journal of Membrane Science, Amsterdam : Elsevier BV, v. 429, p. 190-196, Feb. 2013 | |
dc.identifier | 0376-7388 | |
dc.identifier | http://www.producao.usp.br/handle/BDPI/45480 | |
dc.identifier | 10.1016/j.memsci.2012.11.048 | |
dc.identifier.uri | http://repositorioslatinoamericanos.uchile.cl/handle/2250/1640128 | |
dc.description.abstract | This work reports results from impedance spectroscopy, nuclear magnetic resonance (NMR) and electron paramagnetic resonance (EPR) of chitosan bio-membranes, containing acetic acid and either with or without glycerol. Ionic conductivity value of 2.9x10-5 S/cm was obtained at room temperature for samples prepared with 5 wt% of acetic acid. Activation energies extracted from the conductivity data are in the range of 0.67 to 0.86 eV (65 to 83 kJ/mol). Proton (1H) line shapes and spin-lattice relaxation times were measured as a function of temperature. The NMR results show that the proton mobility of the membranes prepared with glycerol is higher than those prepared without glycerol. EPR experiments were carried out in samples doped with copper perchlorate. Analysis of the spin Hamiltonian parameters indicate that the Cu 2+ ions are located in axially distorted sites, with the cooper ion coordinated to nitrogen and oxygen atoms. The in-plane metal-ligand τ-bonding was evaluated using the EPR data to obtain information about the Cu2+ ligand bond nature for the chitosan bio-membranes | |
dc.language | eng | |
dc.publisher | Elsevier BV | |
dc.publisher | Amsterdam | |
dc.relation | Journal of Membrane Science | |
dc.rights | Copyright Elsevier B.V. | |
dc.rights | restrictedAccess | |
dc.subject | Chitosan membrane | |
dc.subject | Ionic conductivity | |
dc.subject | NMR | |
dc.subject | EPR | |
dc.title | Magnetic resonance study of chitosan bio-membranes with proton conductivity properties | |
dc.type | Artículos de revistas | |