ME - Posters
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- New triazine-phosphonate dopants for proton exchange membranes (PEM) [Poster]Publication . Teixeira, Fatima; Teixeira, António P. S.; Rangel, C. M.ABSTRACT: The establishment of a new paradigm for energy is underway demanding new energy sources for the increasing needs of society with none or lower environmental impact. To reach the ambitious and well defined targets for decarbonized energy systems it is needed new clean technologies. Some of them rely on well-established or emerging electrochemical devices, including batteries, fuel cells and CO2 and water electrolysers, whose applications and performances depend on key components such as their separators/ion-exchange membranes.1,2 The most studied and already commercialized membranes go by the brand name of Nafion, which showed great chemical stability, but their high proton conduction depends on their water content, markedly limiting their operating temperature range. Our previous studies have demonstrated that the incorporation of aryl or heterocyclic phosphonic acid dopants into Nafion, by casting, results in an enhancement of the proton conductivity1-4 and stability5 of the Nafion doped membranes.
- New SPEEK doped membranes for ion exchange polymer electrolytes [Poster]Publication . Teixeira, Fatima; Teixeira, António P. S.; Rangel, C. M.
- Nuclear microprobe: the tool to characterize new materials for energy conversion [Poster]Publication . Corregidor, V.; Alves, L. C.; Barreiros, M. Alexandra; Salomé, P.M.P.
- Optoelectronic Study of Perovskites/SnO2 based Metal-Insulator-Semiconductor Structures [Poster]Publication . Cunha, J.M.V.; Barreiros, M. Alexandra; Curado, M.A.; Lopes, T.S.; Oliveira, K.; Oliveira, A.J.N.; Vinhais, C.; Flandre, Denis; Teixeira, J.P.; Silva, Ana G.; Fernandes, P.A.; Salomé, P.M.P.
- Ultrafast low-temperature crystallization of solar cell graded formamidinium-cesium mixed-cation lead mixed-halide perovskites using a reproducible microwave-based process [Poster]Publication . Brites, Maria João; Barreiros, M. Alexandra; Corregidor, V.; Alves, L. C.; Pinto, Joana V.; Mendes, Manuel Joao; Fortunato, Elvira; Martins, Rodrigo; Mascarenhas, João
- Corrosion protection of PVD and paint coatings for selective solar absorber surfacesPublication . Nunes, A.; Carvalho, Maria João; Cunha Diamantino, Teresa; Fernandes, J. C. S.The selective solar absorber surface is a fundamental part of a solar thermal collector, as it is responsible for the solar radiation absorption and for reduction of radiation heat losses. The surface’s optical properties, the solar absorption (á) and the emittance (å), have great impact on the solar thermal collector efficiency. In this work, two coatings types were studied: coatings obtained by physical vapor deposition (PVDs) and coatings obtained by projection with different paints (PCs) on aluminum substrates. The most common industrial high performing solar selective absorbers are nowadays produced by vacuum deposition methods, showing some disadvantages, such as lower durability, lower resistance to corrosion, adhesion and scratch, higher cost and complex production techniques. Currently, spectrally selective paints are a potential alternative for absorbing surfaces in low temperature applications, with attractive features such as ease of processing, durability and commercial availability with low cost. Solar absorber surfaces were submitted to accelerated ageing tests, specified in ISO 22975-3. This standard is applicable to the evaluation of the long term behavior and service life of selective solar absorbers for solar collectors working under typical domestic hot water system conditions. The studied coatings have, in the case of PVDs solar absorptions between 0.93 and 0.96 and emittance between 0.07 and 0.10, and in the case of PCs, solar absorptions between 0.91 and 0.93 and emittance between 0.40 and 0.60. In addition to evaluating long term behavior based on artificial ageing tests, it is also important to know the degradation mechanism of different coatings that are currently in the market. Electrochemical impedance spectroscopy (EIS) allows for the assessment of mechanistic information concerning the degradation processes, providing quantitative data as output, which can easily relate to the kinetic parameters of the system. EIS measures were carried out on Gamry FAS2 Femostat coupled with a PCL4 Controller. Two electrolytes were used, 0.5 M NaCl and 0.5 M Na2SO4, and the surfaces were tested at different immersion times up to 4 weeks. The following types of specimens have been tested: Aluminium with/without surface treatment, 3 selective paint coatings (one with a poly(urethane) binder and two with silicone binders) and 2 PVD coatings. Based on the behaviour of the specimens throughout the 4 weeks of immersion, it is possible to conclude that the coating showing the best protective properties corresponds to the selective paint coating with a polyurethane resin followed by the other paint coatings, whereas both the PVD coatings do not confer any protection to the substrate, having a deleterious effect as compared to the untreated aluminium reference.
- AA 5083 aluminium alloy corrosion in estuarine environment [Poster]Publication . Marques, Maria João; Alves, Isabel Nascimento; Gonçalves, Rita; Cunha Diamantino, Teresa
- SECMAD : secador solar para madeiras, um caso de estudoPublication . Santos, José António dos; Martins, Maria João; Loureiro, David; Nogueira, António Júlio; Ataíde, Edgar; Enoch, Sandra; Pestana, Luís Câmara; Costa, Arnaldo Jorge Cruz
- High surface area LaNiO3 electrodes for oxygen electrocatalysis in alkaline mediaPublication . Rangel, C. M.; Soares, C. O.; Silva, R. A.; Carvalho, M. D.; Jorge, M. E. Melo; Gomes, A.; Pereira, M. I. da Silva
- Gold electrodeposition from ionic liquids: an alternative to conventional aqueous bathsPublication . Sá, A.I. De; Rangel, C. M.; Quaresma, S.; Eugénio, S.; Vilar, R.