0000000001301398
AUTHOR
Enrique Giménez
Proton conductivity through polybenzimidazole composite membranes containing silica nanofiber mats
The quest for sustainable and more efficient energy-converting devices has been the focus of researchers&prime
Ionic Liquid Composite Polybenzimidazol Membranes for High Temperature PEMFC Applications
A series of proton exchange membranes based on polybenzimidazole (PBI) were prepared using the low cost ionic liquids (ILs) derived from 1-butyl-3-methylimidazolium (BMIM) bearing different anions as conductive fillers in the polymeric matrix with the aim of enhancing the proton conductivity of PBI membranes. The composite membranes prepared by casting method (containing 5 wt. % of IL) exhibited good thermal, dimensional, mechanical, and oxidative stability for fuel cell applications. The effects of anion, temperature on the proton conductivity of phosphoric acid-doped membranes were systematically investigated by electrochemical impedance spectroscopy. The PBI composite membranes containin…
Enhanced Conductivity of Composite Membranes Based on Sulfonated Poly(Ether Ether Ketone) (SPEEK) with Zeolitic Imidazolate Frameworks (ZIFs)
The zeolitic imidazolate frameworks (ZIFs) ZIF-8, ZIF-67, and a Zn/Co bimetallic mixture (ZMix) were synthesized and used as fillers in the preparation of composite sulfonated poly(ether ether ketone) (SPEEK) membranes. The presence of the ZIFs in the polymeric matrix enhanced proton transport relative to that observed for SPEEK or ZIFs alone. The real and imaginary parts of the complex conductivity were obtained by electrochemical impedance spectroscopy (EIS), and the temperature and frequency dependence of the real part of the conductivity were analyzed. The results at different temperatures show that the direct current (dc) conductivity was three orders of magnitude higher for composite …
Diffusivity and free anion concentration of ionic liquid composite polybenzimidazole membranes.
[EN] In this article, PBI composite membranes containing the ionic liquid (IL) 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMIM-NTf2) at 1, 5, 10, 20 and 50 wt% (named PBI-IL-x) have been prepared by a casting method. The internal morphology of the membranes was analyzed by scanning electron microscopy (SEM), revealing that the incorporation of IL promotes the formation of porous channels. Thermal and mechanical stability was confirmed by thermogravimetric analysis (TGA) and tensile test measurements. The ionic transport through membranes was analysed by means of electrochemical impedance spectroscopy (EIS), showing a dependence on the IL loading, reaching a highest condu…
Novel Polycaprolactone Nanocomposites Containing Thymol of Interest in Antimicrobial Film and Coating Applications
It is well-known that the nanocomposites technology can significantly enhance, among others, the thermal, mechanical, and barrier properties of plastics. It is also known that most bioplastics, including the thermoplastic biopolymers, have lower than desired levels for certain properties which makes their use in certain packaging applications problematic. The combination of active technologies such as antimicrobials and nanotechnologies such as nanocomposites can synergistically lead to bioplastic formulations with balanced properties and functionalities for their implementation in packaging applications. The present work presents the development and characterization of novel nanocomposite…
Phosphoric Acid Doped Polybenzimidazole (PBI)/Zeolitic Imidazolate Framework Composite Membranes with Significantly Enhanced Proton Conductivity under Low Humidity Conditions
The preparation and characterization of composite polybenzimidazole (PBI) membranes containing zeolitic imidazolate framework 8 (ZIF-8) and zeolitic imidazolate framework 67 (ZIF-67) is reported. The phosphoric acid doped composite membranes display proton conductivity values that increase with increasing temperatures, maintaining their conductivity under anhydrous conditions. The addition of ZIF to the polymeric matrix enhances proton transport relative to the values observed for PBI and ZIFs alone. For example, the proton conductivity of PBI@ZIF-8 reaches 3.1 10&minus
Proton Conducting Electrospun Sulfonated Polyether Ether Ketone-Graphene Oxide Composite Membranes
[EN] A series of novel composite membranes, based on sulfonated poly(ether ketone) (SPEEK) with a graphene oxide (GO) layer, were prepared. One contained a GO layer sandwiched between the SPEEK-polyvinyl alcohol (PVA) matrix (SPEEK/PVA@GO), and another deposited thin layers of GO on the nanofibers of SPEEK-polyvinyl butyral (PVB), with both sandwiched in the phase matrix of SPEEK-PVA (SPEEK/PVA@GO-NF). Various nanofiber thicknesses were studied by varying the electrospinning time. The prepared composite membranes with different nanofiber thicknesses were characterized by scanning electron microscopy, water uptake, ionic exchange capacity, thermogravimetric analysis, mechanical properties an…
Nanorings and rods interconnected by self-assembly mimicking an artificial network of neurons
[EN] Molecular electronics based on structures ordered as neural networks emerges as the next evolutionary milestone in the construction of nanodevices with unprecedented applications. However, the straightforward formation of geometrically defined and interconnected nanostructures is crucial for the production of electronic circuitry nanoequivalents. Here we report on the molecularly fine-tuned self-assembly of tetrakis-Schiff base compounds into nanosized rings interconnected by unusually large nanorods providing a set of connections that mimic a biological network of neurons. The networks are produced through self-assembly resulting from the molecular conformation and noncovalent intermo…
CCDC 936468: Experimental Crystal Structure Determination
Related Article: Martha V. Escárcega-Bobadilla, Gustavo A. Zelada-Guillén, Sergey V. Pyrlin, Marcin Wegrzyn, Marta M.D. Ramos, Enrique Giménez, Andrew Stewart, Gerhard Maier, Arjan W. Kleij|2013|Nat.Commun.|4|2648|doi:10.1038/ncomms3648
CCDC 936469: Experimental Crystal Structure Determination
Related Article: Martha V. Escárcega-Bobadilla, Gustavo A. Zelada-Guillén, Sergey V. Pyrlin, Marcin Wegrzyn, Marta M.D. Ramos, Enrique Giménez, Andrew Stewart, Gerhard Maier, Arjan W. Kleij|2013|Nat.Commun.|4|2648|doi:10.1038/ncomms3648
CCDC 936467: Experimental Crystal Structure Determination
Related Article: Martha V. Escárcega-Bobadilla, Gustavo A. Zelada-Guillén, Sergey V. Pyrlin, Marcin Wegrzyn, Marta M.D. Ramos, Enrique Giménez, Andrew Stewart, Gerhard Maier, Arjan W. Kleij|2013|Nat.Commun.|4|2648|doi:10.1038/ncomms3648