Nanoporous PBI Membranes by Track-Etching for High Temperature PEMFC

This article describes for the first time the preparation of conducting track-etched PBI membranes 25 mm thick with pore diameter values varying from 15 nm to 50 nm and overall porosity up to 10%. The TGA, DSC and FTIR characterization results for the so obtained nanoporous membranes reveal the chemical modification of PBI upon irradiation along the track walls. A clear conduction outperforming is shown by phosphoric acid doped track-etched PBI in comparison with dense PBI counterparts. This behavior could be explained by the effective contribution of additional pathways for proton transport involving shorter benzimidazole fragments, cross-linked PBI nanodomains and free amphoteric phosphoric acid molecules settled on the pore walls

Fungal communities isolated from dead apple leaves from orchards in Quebec

Le champignon causant la tavelure du pommier, Venturia inaequalis, hiverne dans les feuilles mortes de pommier (Malus pumila) sous forme de pseudothèces. Les objectifs de cette étude étaient de monter une collection de champignons afin de vérifier subséquemment leur résistance au froid et leur potentiel antagoniste contre V. inaequalis et d'acquérir des connaissances sur la microflore des feuilles mortes de pommiers. Des champignons ont été isolés sur des feuilles mortes de pommiers récoltées au printemps et à l'automne de 1993. Au total, 345 isolats fongiques provenant de 49 genres ont été identifiés. Quinze genres sont rapportés pour la première fois comme colonisateurs des feuilles de pommiers en Amérique du Nord.Venturia inaequalis, the causal agent of apple scab, overwinters in apple (Malus pumila) leaves on the orchard floor by producing pseudothecia. The objectives of this survey were to make a collection of fungi to be subsequently tested for their potential as psychrophile biocontrol agents against V. inaequalis and to acquire knowledge on the diversity of the microflora of dead apple leaves. Fungi were recovered from dead apple leaves collected in the spring and fall of 1993. A total of 345 isolates from 49 genera were identified. Fifteen gene were not previously recorded as colonizers of apple leaves in North America

Integration of functional complex oxide nanomaterials on silicon

The combination of standard wafer-scale semiconductor processing with the properties of functional oxides opens up to innovative and more efficient devices with high value applications which can be produced at large scale. This review uncovers the main strategies that are successfully used to monolithically integrate functional complex oxide thin films and nanostructures on silicon: the chemical solution deposition approach (CSD) and the advanced physical vapor deposition techniques such as oxide molecular beam epitaxy (MBE). Special emphasis will be placed on complex oxide nanostructures epitaxially grown on silicon using the combination of CSD and MBE. Several examples will be presented, with a particular stress on the control of interfaces and crystallization mechanisms on epitaxial perovskite oxide thin films, nanostructured quartz thin films, and octahedral molecular sieve nanowires. This review enlightens on the potential of complex oxide nanostructures and the combination of both chemical and physical elaboration techniques for novel oxide-based integrated devicesAC acknowledges the financial support from 1D-RENOX project (Cellule Energie INSIS-CNRS). J.M.V.-F. also acknowledges MINECO for support with a Ph.D. grant of the FPI program. We thank David Montero and L. Picas for technical support. We also thank P. Regreny, C. Botella, J.B. Goure for technical assistance on the Nanolyon technological platform. We acknowledge MICINN (MAT2008-01022 MAT2011-28874-c02-01 and MAT2012-35324), Consolider NANOSELECT (CSD2007-00041), Generalitat de Catalunya (2009 SGR 770 and Xarmae), and EU (HIPERCHEM, NMP4-CT2005-516858) projects. The HAADF-STEM microscopy work was conducted at the Center for Nanophase Materials Sciences, which is a DOE Office of Science User Facility. This research was supported by the European Research Council (ERC StG-2DTHERMS), Ministerio de Economía y Competitividad of Spain (MAT2013-44673-R) and EU funding Project “TIPS” Thermally Integrated Smart Photonics Systems Ref: 644453 call H2020-ICT-2014-1S

Crystal engineering and ferroelectricity at the nanoscale in epitaxial 1D manganese oxide on silicon

Ferroelectric oxides have attracted much attention due to their wide range of applications, particularly in electronic devices such as nonvolatile memories and tunnel junctions. As a result, the monolithic integration of these materials into silicon technology and their nanostructuration to develop alternative cost-effective processes are among the central points in the current technology. In this work, we used a chemical route to obtain nanowire thin films of a novel Sr1+δMn8O16 (SMO) hollandite-type manganese oxide on silicon. Scanning transmission electron microscopy combined with crystallographic computing reveals a crystal structure comprising hollandite and pyrolusite units sharing the edges of their MnO6 octahedra, resulting in three types of tunnels arranged along the c axis, where the ordering of the Sr atoms produces natural symmetry breaking. The novel structure gives rise to ferroelectricity and piezoelectricity, as revealed by local direct piezoelectric force microscopy measurements, which confirmed the ferroelectric nature of the SMO nanowire thin films at room temperature and showed a piezoelectric coefficient d33 value of 22 ± 6 pC N−1. Moreover, we proved that flexible vertical SMO nanowires can be harvested providing an electrical output energy through the piezoelectric effect, showing excellent deformability and high interface recombination. This work indicates the possibility of engineering the integration of 1D manganese oxides on silicon, a step which precedes the production of microelectronic devices.A. C.-G., C. J., R. G.-B. and J. M. V.-F. acknowledge the financial support from the European Research Council (ERC) under the European Union's Horizon 2020 research and innovation program (No. 803004) and the French Agence Nationale de la Recherche (ANR), project Q-NOSS ANR ANR-16-CE09-0006-01. This project has received funding from the EU-H2020 research and innovation program under grant agreement no 654360 having benefitted from the access provided by ICMAB-CSIC in Barcelona within the framework of the NFFA-Europe Transnational Access Activity. This project has received funding from the European's Union Horizon 2020 research and innovation programme under Grant No. 823717-ESTEEM3, the Spanish Ministry of Economy and Competitivity through Project MAT2017-82970-C2-2-R, and the Aragon Regional Government through Project No. E13_20R (with European Social Fund). We acknowledge SOLEIL for provision of synchrotron radiation facilities, and we would like to thank Pierre Fertey for assistance in using beamline Cristal. J. G. also acknowledges the Ramon y Cajal program (RYC-2012-11709). The authors thank D. Montero for providing the FEGSEM images. N. M. acknowledges the Spanish Ministry of Science, Innovation and Universities through Severo Ochoa FUNFUTURE (CEX2019-000917-S) and SUMATE (RTI2018-095853-B-C21) projects, co-financed by the European Regional Development Fund. The FEGSEM instrumentation was facilitated by the Institut des Matériaux de Paris Centre (IMPC FR2482). The authors thank Frederic Pichot for his expertise and advice during the nanowire lithographic process. The STEM microscopy work was conducted in the Laboratorio de Microscopias Avanzadas (LMA) at Instituto de Nanociencia de Aragon (INA) at the University of Zaragoza.Peer reviewe

Track-etched Membrane - Dynamics of Pore Formation

The dynamics of pore formation during etching of heavy ion (Ar9+ -4.5 MeV/amu) irradiated bisphenol-A polycarbonate (PC) and polyethylene terephthalate (PET) films is determined by a conductivity cell. This work presents the theoretical basis of this method and describes the experimental procedure. The obtained results allow the determination of the track (V(t)) and bulk (V(g)) etch rates, and an estimate of the damage zone diameter in PC before etching

Modification of Peek Model Compounds and Peek Film By Energetic Heavy-ion and Ultraviolet Irradiations

To prepare nuclear track membranes from poly(aryl ether ether ketone) (PEEK) film, we first determined the modifications induced by heavy ion and UV irradiations in this polymer and two of its model compounds, paraphenoxy benzophenone (PPB) and diphenoxy benzophenone (DPB). This article displays the first results obtained by SEC, HPLC, DSC, FTIR, UV and C-13 NMR

Pore shape control in nanoporous particle track etched membrane

This paper shows the possibility of preparing nanoporous particle track etched membranes (nanoPTM) with perfectly smooth and cylindrical pores from polycarbonate film. Interest in the template use of these nanoPTM for the production of polymeric or metallic nanoscale materials is also emphasized. (C) 2001 Elsevier Science B.V. All rights reserved

Track-etch templates designed for micro- and nanofabrication

This paper reports on the advances made in the laboratory in the development of porous media by track-etching process, and on their use by research partners as templates for the micro- or nanofabrication of polymeric and metallic wires or tubules with interesting properties. It mainly relates to the development of nanoporous polycarbonate-based templates, and more precisely to pore-shape control in polycarbonate films, to the development of supported track-etch templates and to the feasibility of template patterning; recent results on the development of templates from polyimide support are also reported. Finally, some nanontaterial synthesis processes and properties are listed, with references to published papers. (C) 2003 Elsevier B.V. All rights reserved

Heavy-ion Tracks in Polycarbonate - Comparison With a Heavy-ion Irradiated Model-compound (diphenyl Carbonate)

The chemical modifications induced by energetic heavy ion irradiation of polycarbonate (PC) film are determined by GPC, HPLC, ESR, TGA, IR and UV spectrophotometry. The main results of the irradiation are creation of radicals, chain scission, cross-linking and appearance of new chemical groups in the main polymer chain. As far as the creation of new groups is concerned, they are determined by means of a model compound of PC: the diphenyl carbonate (DPC). The following compounds are identified after energetic heavy ion irradiation of DPC: salicylic acid, phenol, 4,4'-biphenol, 2,4'-biphenol, 2,2'-biphenol, 4-phenoxyphenol, 2-phenoxyphenol, phenyl ether, phenyl benzoate, phenyl salicylate, 2-phenylphenol and 2-phenoxyphenyl benzoate. A similarity between the heavy ion irradiation and a heat treatment has also been established with DPC. On the basis of these results, we try to give an explanation of the preferential attack along the tracks of the irradiated film. Also, an explanation of the well-known beneficial effect of an UV exposition of the irradiated film on the selectivity of this preferential chemical attack is suggested

Energetic heavy ion tracks in PEEK film

Some of the modifications induced in poly(ether-ether-ketone) (PEEK) film irradiated with energetic heavy ions (Ar, Kr or Pb) are determined by gravimetry, SEC and ESR measurements. First etching experiments done on irradiated PEEK film show a preferential ion track etching