Entity

Time filter

Source Type


Moreira S.D.F.C.,University of Minho | Silva C.J.R.,University of Minho | Prado L.A.S.A.,TU Hamburg - Harburg | Costa M.F.M.,University of Minho | And 3 more authors.
Journal of Polymer Science, Part B: Polymer Physics | Year: 2012

Flexible hybrid xerogels bringing together high optical transparency up to 96%, low shrinkage down to 5.5%, very smooth surface (average roughness of about 0.3 nm) and thermal stability up to 200 °C were achieved as a result of the optimization of sol-gel preparative method and a new combination of sol-gel precursors. Two types of hybrid materials (hereafter referred, respectively, as urea-silicate and amino-alcohol-silicate gels) were synthesized in this work. The shrinkage and the transparency of these materials have been drastically improved by using two different derived siloxanes (3-isocyanate propyltriethoxysilane and 3-glycidoxypropyltrimethoxysilane) and two amine-terminated polyether precursors with different molecular weights. A drying process was implemented to minimize yellowing of prepared samples. Under these conditions, we were able to efficiently reproduce a well-defined imprinted pattern at materials surface by using an original casting mould. The study of the diffraction characteristics of the obtained grating revealed a good reproducibility of the imprinted grating that shows to be comparable with the original mould. The developed methodology opens the possibility to produce diffraction lenses with a wide range of forms by a simple method based on sol-gel process. © 2011 Wiley Periodicals, Inc. Source


Grant
Agency: Cordis | Branch: FP7 | Program: MC-ITN | Phase: FP7-PEOPLE-ITN-2008 | Award Amount: 1.74M | Year: 2009

Water arguably is the only true renewable source of hydrogen fuel. However extraction of the hydrogen requires significant energy input; either thermal, electrical or light. By utilizing a renewable electrical energy source, water electrolysis offers a practical route to sustainable hydrogen production. The coupling of electrolysis with renewable electrical energy (e.g. from wind) enables the full available energy to be stored as fuel (hydrogen) when there is low electrical energy demand. In addition water electrolysis offers a convenient method of localised hydrogen supply which overcomes problems and issues of its distribution. The use of a proton exchange membrane (PEM) or solid polymer electrolyte (SPE) in water electrolysis enables hydrogen production from pure (demineralised) water and electricity. PEM water electrolysis systems offer advantages over traditional technologies; greater energy efficiency, higher production rates (per unit electrode area), and more compact design. A restricting aspect of water electrolysis is the relatively high cost of the electrical energy. This programme is targeted at reducing this electrical energy requirement and reducing electrolyser cost by researching new materials for electrodes and membranes in PEM electrolysers that function at higher temperatures; thereby reducing thermodynamic energy requirements and accelerating electrode kinetics. Thus the aim of this research is to form a collaborative training programme that focuses on hydrogen production from water using advanced, medium temperature proton exchange membrane electrolysers. By operating cells at higher temperatures the free energy of the cell reaction falls and thus lower standard potentials are required. In addition, moving to the higher temperatures can enable reduction in Pt catalyst use and/or use of non-Pt catalysts for electrodes. In these ways we can reduce the capital and operating costs of PEM hydrogen electrolysers. Although high temperature elec


Grant
Agency: Cordis | Branch: FP7 | Program: BSG-SME | Phase: SME-2012-1 | Award Amount: 1.48M | Year: 2012

Climate change is one of the largest threats facing the world today. At the forefront of combating this issue are low carbon technologies. Recently, HEV (Hybrid Electric Vehicles) have come forward as the most achievable solution of the moment. At present, HEV use expensive Lithium ion and NiM batteries due to their high power to weight ratio. Lead-acid batteries are a cheaper option, but due to their lower power to weight ratio they are not used. The MEMLAB project aims to solve this through the development of lightweight electrodes for use in lead-acid batteries. The project will use state-of-the-art fibre production technology to create titanium and aluminium fibre networks. These will be coated in lead and lead oxide. The objective is to achieve a greater than 50% reduction in the overall weight of a lead-acid battery thereby significantly increasing their power to weight ratio making them a realistic alternative for application in hybrid electric vehicles. In addition to application in the hybrid electric vehicle market, the replacement of standard lead-acid batteries, containing large and heavy quantities of lead, by lightweight lead-acid batteries will also lead to a significant reduction in the polluting effect of road-going vehicles due to the large quantity of vehicles in use. The number of lead-acid batteries currently manufactured in Europe is approximately 70 million per year. The project consortium has been specifically constructed so that the research partners deliver the technical research required by the SME consortium partners. Successful completion of project MEMLAB will significantly strengthen the competitive position of the participating SMEs by both opening new markets, hybrid electric vehicles, and expanding opportunities in existing markets, lead-acid batteries. Furthermore, the project consortium will also seek to identify and evaluate further market applications, for example industrial filtration as well as fuel cells.


Grant
Agency: Cordis | Branch: FP7 | Program: JTI-CP-FCH | Phase: SP1-JTI-FCH.2013.3.1 | Award Amount: 4.41M | Year: 2014

The project aims at developing reliable predictive models to estimate long-term (i.e. > 20 kh) performance and probability of failure of SOFC stacks based on existing materials and design produced by the industrial partners. This will allow the realization of stacks with extended service intervals and reduced maintenance cost with respect to the present stack technology. The extension of service life will be supported by the introduction of Early Warning Output Signals triggered counterstrategies. The project is structured into three phases: consolidation of knowledge and refinement of models on a previously operated State of Art stack (1st Loop); enhancement of materials, design and predictive models via iterative loops (Improvement Iterative Loop); statistical validation of achieved improvements via standard and accelerated tests (Validation Process). The stack is a system of interfaces/interphases giving rise to complex phenomena that which have to be separated in single phenomena processes. The single phenomena are generated by the minimum of interfaces/interphases in a quasi-independent way and therefore suitable for a separate deep investigation via micro-samples studies. The improvements will be especially validated by: the application of accelerated test protocols; the evaluation of robustness of stacks and components toward load cycles and thermal cycles. The comparison with an operating not cycled stack will give the value of performance (voltage) loss for the rated stack life cycle that has to be <5% for 100 load cycles (idle to rated load) or 50 thermal cycles (room temperature to operating temperature). The outcomes will be statistically demonstrated by operating 6 stacks in standard conditions and a minimum of 3 micro-sample per interphase in standard, cycled and accelerated conditions with constant monitoring via modelling.


Grant
Agency: Cordis | Branch: FP7 | Program: CP-FP | Phase: ENERGY-2007-1.1-03 | Award Amount: 4.37M | Year: 2008

IDEAL-Cell proposes to develop a new innovative and competitive concept of a high temperature Fuel Cell, operated in the range 600-700C, based on the junction between a PCFC anode/electrolyte part and a SOFC electrolyte/cathode, through a mixed H2 and O2 conducting porous ceramic membrane. Protons created at the anode progress toward the central membrane to meet with Oxygen ions created at the cathode, to form water, which is evacuated through the interconnected porosity network. Therefore, in our concept, Hydrogen, Oxygen and water are located in 3 independent chambers, which allows avoiding all the detrimental consequences linked to the presence of water at electrodes (low fuel and electrical efficiency, interconnect corrosion, need for a gas counter-flow). The IDEAL-Cell concept brings a considerable enhancement of the overall system efficiency (fine-tuning of the catalytic properties of the electrode, possibility of applying a pressure on both the electrode sides, more simpler and compact stack-design with less sophisticated interconnects, more efficient pre-heating of gas, simplified heat exchange system for co-generation, availability of high quality pure water for vaporeforming ). This 4-year project, divided in 2 parts, is organized so that the risk is minimized at each step. The first 2 years will focus on the proof of the concept with routine materials; the last 2 years will be dedicated to the development of an optimized short-stack with advanced materials and architecture. The project work programme is based on extensive theory and modelling, material development, testing techniques development, benchmarking and dissemination of the knowledge acquired during the duration of the project. The best European teams have been carefully selected according to their complementary expertises and skills, and so that the type of activities involved (academic research, applied research, materials supply) ensures the success of the IDEAL-Cell project.

Discover hidden collaborations