Displaying items by tag: Sourcehttp://www.data-mining-lernen.deSun, 29 May 2016 15:24:29 +0200Joomla! - Open Source Content Managementde-deBetter membranes for fuel cellshttp://www.data-mining-lernen.de/index.php/get-in-contact/item/1514-better-membranes-for-fuel-cellshttp://www.data-mining-lernen.de/index.php/get-in-contact/item/1514-better-membranes-for-fuel-cellsBetter membranes for fuel cells

Better membranes for fuel cells

ID: F1510-10

A gas cellular can produce electrical energy through a chemical reaction between a gas and oxygen. Those that use a proton-conducting polymer membrane as the electrolyte are known as proton exchange membrane (PEM) gas cells. These are semipermeable membranes generally made from ionomers and created to carry out protons while being impermeable to gases. Nevertheless, until now, PEM fuel cells have actually unsuccessful mostly because of mechanical failure of the membrane. To increase their durability and life time, a new project had been founded. One of the absolute most common and commercially available PEM materials is the fluoropolymer perfluorosulfonic acid (PFSA). The project made great strides in obtaining low equivalent-weight (EW) PFSA ionomers with improved mechanical properties contrasted to the state of the art. Benchmark ionomers may have been hitherto the best materials in the lab. Nevertheless, the task proved that they were not the best in terms of durability when membrane layer electrode assemblies (MEAs) were assessed after 100 hours of continuous procedure. To this end, experts utilized reduced EW ionomers in their bid to prepare membranes with robust mechanical properties. Their approaches relied on the usage of chemical, thermal, and processing and filler reinforcement techniques. In particular, the focus had been on checking out ionic cross-links during emulsion polymerisation and membrane layer casting. This approach leads to non-linear ionomer molecules with large molecular weight that overcome problems linked with membrane layer dimensional changes – i.e. swelling. Researchers also used electrospinning to produce organic and inorganic fibres for mechanically reinforcing the low EW standard ionomers. Through nanofibre reinforcement, scientists reported significant improvement of mechanical properties of the last membranes and greater durability, with conductivity being greater contrasted to the benchmark membrane. Another technique to mechanically strengthen the standard ionomers had been through ionic cross-linking based on nanoparticles. A number of membranes had been prepared utilizing nanoparticle fillers of different hydrophobicity. With in situ tests designed to accelerate mechanical degradation, the stabilised MEAs demonstrated improved durability, with less than 3 % voltage loss after 2 000 hours of operation.

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  • Energy
  • Source
  • Fuel
  • Cell
  • Membrane
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    grond@numberland.de (Administrator)Get in ContactTue, 27 Oct 2015 21:11:56 +0100
    Better materials for better LEDshttp://www.data-mining-lernen.de/index.php/get-in-contact/item/1505-better-materials-for-better-ledshttp://www.data-mining-lernen.de/index.php/get-in-contact/item/1505-better-materials-for-better-ledsBetter materials for better LEDs

    Better materials for better LEDs

    ID: F1510-01

    Keeping great promises for reduced energy usage and high conversion efficiencies, lighting fixtures with solid-state light sources have the possible to revolutionise the lighting industry. Additional improvements in light-emitting efficiency at high currents, with excellent color making at low expense would considerably speed up the widespread uptake of the technology. A new project is investigating the materials for these improved lighting products by developing new large-area semi-polar templates utilizing sapphire and silicon substrates. These semipolar templates help reduce the inbuilt electric fields in LEDs which affect their color security and effectiveness and supply a big area, low cost platform for the growth of the LED levels. The task is additionally making use of the indium aluminium gallium nitride (InAlGaN) material for the light-emitting layers, focusing on blue and yellow emission. A major challenge is patterning of the wafer to produce and coalesce semi-polar planes on the structured sapphire substrate. To this end, experts are assessing the impact of substrate fine orientation and growth parameters through X-ray measurements, luminescence and atomic-scale imaging. Metalorganic and hydride vapour phase epitaxy are used to develop levels on the substrates. The active light-emitting material comprises of quantum wells that have actually large optical efficiency and excellent color purity. Project partners used the HVPE technique to overgrow GaN on top of a GaN layer grown by MOVPE that had been at first prepared on pre-structured sapphire. InGaN layers had been then grown on semi-polar GaN templates with various growth conditions. Semi-polar InGaN structures with different thicknesses had been optimised, reaching large transformation light-emitting efficiencies in the blue and yellow spectra. A move from growing products on semi-polar substrates is assisting to overcome issues related to decrease in LED light-emitting efficiency. Changing present lighting technologies with solid-state lighting based on InGaN LEDs should enable a decrease in electrical energy by up to 5 %.

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    • Energy
    • LED
    • Light
    • Source
    • Optics
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      grond@numberland.de (Administrator)Get in ContactSat, 03 Oct 2015 22:07:04 +0200
      Photocatalysis assisted by nanocarbonshttp://www.data-mining-lernen.de/index.php/get-in-contact/item/1463-photocatalysis-assisted-by-nanocarbonshttp://www.data-mining-lernen.de/index.php/get-in-contact/item/1463-photocatalysis-assisted-by-nanocarbonsPhotocatalysis assisted by nanocarbons

      Photocatalysis assisted by nanocarbons

      ID: F1505-09

      With the development οf clean рower sоurces as one of the beѕt challеnges of the twenty-first century, the uѕage of sυnshine to driνe cаtalytic responѕеs, and pаrticularly hуdrogen productіоn frοm water splitting, has emergеd аs a promisіng course. This project takes advаntаge οf the big collectіon οf nanomaterials to prοdυce brand nеw hybrids wіth еnhanced properties that hаpрen in greater photocatalytic efficiency.
      Utilising the sυn's light in artіfiсial рhοtоsynthetіc deviceѕ to рroduce mοlecular hуdrogen (H2) for uѕe in H2 fuel cеlls is thе sυbjeсt of mυch research. Photocatalytic systems split water particles into H2 and oxygen. Novel materials with greater efficiency and security at reduced costs are needed. To attain this, sciеntiѕtѕ are сheckіng out hybrid nanomaterials made of nano-struсturеd cаrbоn and inorganic semicοnductors.
      A key aspect of the task is the fоcus on іntеrfacіal engineering as a mechanism to contrоl charge transfer processeѕ betweеn the hybrids, thus bοost сharge lifetime and photocatalytic performance. The project has made progress in οptimisіng synthеtic channels to aсhіeve. Cutting-еdge spectroscopy strategies hаve actually provided a unique inѕight into thе electronic prореrties at the nanοcarbon/inorganic semicondυctor junctіon, providing elements tо adјυst the artificial routes apрropriately.
      In the short-term, production of this task is contributing to the logical design and synthesis of new nanostructured hybrids with enhanced catalytic performance in sustainable power programs, such as water splitting, water purification, photoelectrochemistry and photovoltaic products. In the lengthy term, these nanostructured hybrid systems will add to solve energy challenges of the future.

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      • Coatings
      • Atmosphere
      • Photocatalytic
      • Nano
      • Carbon
      • Clean
      • Power
      • Source
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        grond@numberland.de (Administrator)Get in ContactWed, 27 May 2015 09:35:56 +0200