Figueiredo, V., Pinto, Joana, Deuermeier, J., Barros, R., Alves, C, Martins, Fortunato E.
2013.
p-Type CuxO Thin-Film Transistors Produced by Thermal Oxidation. Journal of Display Technology. 9(9):735-740.
Parthiban, S., Elangovan, E., Nayak, Pradipta K., Gonçalves, G., Nunes, D., Pereira, Barquinha, Busani, Tito, Fortunato, Martins R.
2013.
Performances of Microcrystalline Zinc Tin Oxide Thin-Film Transistors Processed by Spray Pyrolysis. Journal of Display Technology, . 9(10):825-831.
Ramos, A.M., Pereira, Cidade, M.T., Pereira, Branquinho, R., Pereira, Martins, Fortunato E.
2013.
Preparation and characterization of cellulose nanocomposite hydrogels as functional electrolytes. Solid State Ionics. 242:26-32.
B.A, S, M. E, L. B, R.C.C. M.
2013.
Preparation method and thermal properties of samarium andeuropium-doped alumino-phosphate glasses. Materials Science and Engineering: B.
AbstractThe present work investigates alumino-phosphate glasses from Li2O–BaO–Al2O3–La2O3–P2O5 system containing Sm3+ and Eu3+ ions, prepared by two different ways: a wet raw materials mixing route followed by evaporation and melt-quenching, and by remelting of shards. The linear thermal expansion coefficient measured by dilatometry is identical for both rare-earth-doped phosphate glasses. Comparatively to undoped phosphate glass the linear thermal expansion coefficient increases with 2 × 10−7 K−1 when dopants are added. The characteristic temperatures very slowly decrease but can be considered constant with atomic weight, atomic number and f electrons number of the doping ions in the case of Tg (vitreous transition temperature) and Tsr (high annealing temperature) but slowly increase in the case of Tir (low annealing temperature–strain point) and very slowly increase, being practically constant in the case of TD (dilatometric softening temperature). Comparatively to undoped phosphate glass the characteristic temperatures of Sm and Eu-doped glasses present lower values. The higher values of electrical conductance for both doped glasses, comparatively to usual soda-lime-silicate glass, indicate a slightly reduced stability against water. The viscosity measurements, showed a quasi-linear variation with temperature the mean square deviation (R2) being ranged between 0.872% and 0.996%. The viscosity of doped glasses comparatively to the undoped one is lower at the same temperature. Thermogravimetric analysis did not show notable mass change for any of doped samples. DSC curves for both rare-earth-doped phosphate glasses, as bulk and powdered samples, showed Tg values in the range 435–450 °C. Bulk samples exhibited a very weak exothermic peak at about 685 °C, while powdered samples showed two weak exothermic peaks at about 555 °C and 685 °C due to devitrification of the glasses. Using designed melting and annealing programs, the doped glasses were improved regarding bubbles and cords content and strain elimination.
Baumann, M.
2013.
Prospective system analysis of stationary battery systems under the frame of Constructive Technology Assessment. Enterprise and Work Innovation Studies. 9(9):9-27.
AbstractThe ongoing German energy transition causes a higher demand for reliable energy storage in the future. This increasing demand for sustainable, cheap, safe and efficient energy storage systems has caused a stronger public debate about the potential benefits of grid battery storage according to sustainability. This circumstance led to the preposition that there is a need for the development of a proper ex-ante assessment strategy to support technology uptake. The developed approach represents a framework for prospective system analysis (PSA) using the heuristics of constructive technology assessment to identify consequences, application possibilities or threats in the technological trajectory of grid battery storage. Within this framework PSA is used to quantitatively assess economic, environmental and social aspects along the entire life cycle of electrochemical energy storage technologies in order to identify hotspots according to sustainability. The Analytic Hierarchic Process (AHP) supports multiple methods in data collection and enables the analyst to combine results from PSA with qualitative actor notions about technology according to the “world” where it is embodied. In this sense AHP enables to achieve an optimum construct of technology from a stakeholder view point. The developed approach represents an efficient research strategy to shape technology in a sustainable way in frame of „Responsible Research and Innovation“.
Martins, Ahnood, Arman, Correia, Nuno, Pereira, Barros, R., Barquinha, Costa, Ferreira, Nathan, Arokia, Fortunato E.
2013.
Recyclable, Flexible, Low-Power Oxide Electronics. Advanced Functional Materials. 23(17):2153-2161.
Araújo, A, Barros R, Mateus T, Gaspar D, Neves N, Vicente A, Filonovich SA, Barquinha P, Fortunato E, Ferraria AM, do Rego ABM, Bicho A, Águas H, Martins R.
2013.
Role of a disperse carbon interlayer on the performances of tandem a-Si solar cells. Science and Technology of Advanced Materials. 14(4)
Borlido, L, Moura L, Azevedo AM, Roque ACA, Aires‐Barros MR, Farinha JPS.
2013.
Stimuli‐Responsive magnetic nanoparticles for monoclonal antibody purification. Biotechnology Journal. 8(6):709–717.
AbstractMonoclonal antibodies (mAbs) are important therapeutic proteins. One of the challenges facing large-scale production of monoclonal antibodies is the capacity bottleneck in downstream processing, which can be circumvented by using magnetic stimuli-responsive polymer nanoparticles. In this work, stimuli-responsive magnetic particles composed of a magnetic poly(methyl methacrylate) core with a poly(N-isopropylacrylamide-co-acrylic acid) (P(NIPAM-co-AA)) shell cross-linked with N, N'-methylenebisacrylamide were prepared by miniemulsion polymerization. The particles were shown to have an average hydrodynamic diameter of 317 nm at 18°C, which decreased to 277 nm at 41°C due to the collapse of the thermo-responsive shell. The particles were superparamagnetic in behavior and exhibited a saturation magnetization of 12.6 emu/g. Subsequently, we evaluated the potential of these negatively charged stimuli-responsive magnetic particles in the purification of a monoclonal antibody from a diafiltered CHO cell culture supernatant by cation exchange. The adsorption of antibodies onto P(NIPAM-co-AA)-coated nanoparticles was highly selective and allowed for the recovery of approximately 94% of the mAb. Different elution strategies were employed providing highly pure mAb fractions with host cell protein (HCP) removal greater than 98%. By exploring the stimuli-responsive properties of the particles, shorter magnetic separation times were possible without significant differences in product yield and purity.
Ferreira, I, Baptista AC, Leitão JP, Soares J, Fortunato E, Martins R, Borges JP.
2013.
Strongly Photosensitive and Fluorescent F8T2 Electrospun Fibers. Macromol Mater Eng. 298(2):174-180., Number 2
AbstractElectrospun fibers of poly[(9,9-dioctylfluorenyl-2,7-diyl)-co-bithiophene] (F8T2) with exceptional electro-optical performance are obtained. The I/T characteristics measured in fibers with 7–15 µm diameter and 1 mm length show a semiconductor behavior; their thermal activation energy is 0.5 eV and the dark conductivity at RT is 5 × 10−9 (Ω cm)−1. Besides exhibiting a photosensitivity of about 60 under white light illumination with a light power intensity of 25 mW · cm−2, the fibers also attain RT photoluminescence in the cyan, yellow, and red wavelength range under ultraviolet, blue, and green light excitation, respectively. Optical microscope images of F8T2 reveal homogeneous electrospun fibers, which are in good agreement with the uniformly radial fluorescence observed.
Bahubalindruni, Ganga, Tavares, Vitor Grade, Barquinha, Duarte, Candido, de Oliveira, Pedro Guedes, Martins, Fortunato E.
2013.
Transparent Current Mirrors With a-GIZO TFTs: Neural Modeling, Simulation and Fabrication. Journal of Display Technology. 9(12):1001-1006.
Baumann, M.
2013.
{A constructive technology assessment of stationary energy storage systems: prospective life cycle orientated analysis}. , Number 01/2013: Universidade Nova de Lisboa, IET/CICS.NOVA-Interdisciplinary Centre on Social Sciences, Faculty of Science and Technology
AbstractEnvironmental concerns over the use of fossil fuels and their resource constraints have increased the interest in generating electric energy from renewable energy sources (RES) to provide a sustainable electricity supply. A main problem of those technologies (wind or solar power generation) is that they are not constant and reliable sources of power. This results inter alia in an increased demand of energy storage technologies. Related stake holders show a big interest in the technical, economic and ecologic aspects of new emerging energy storage systems. This comes especially true for electrochemical energy storage systems as different Li-Ion batteries, Sodium Sulfur or Redox Flow batteries which can be utilized in all grid voltage levels, a wide range of grid applications as well as end user groups (e.g. private households, industry). A prospective and active Constructive Technology Assessment (CTA) can help to minimize potential mismatches, wrong investments, possible social conflicts, and environmental impacts of new energy storage technologies in an early development stage. It is insufficient to exclusively look at the operation phase to assess a technology. Such an approach can lead to misleading interpretations and can furthermore disregard social or ecological impact factors over the whole life cycle. Different energy storage technologies have to be evaluated in a prospective manner with a full integrated sustainability and life cycle approach to form a base for decision making and to support technology developers in order to allow distinctions between more or less sustainable battery technology variations. Therefore CTA is used as a scientific approach using several “neighbouring” engineering orientated disciplines e.g. Life Cycle Analysis (LCA), Social Life Cycle Assessment (SLCA) or Life Cycle Costs (LCC) and their methodologies which were initially developed for other purposes.The aim of the presented PhD Thesis is to make an economic, technological and
dos Santos, R, Rocha A, Matias A, Duarte C, de Sá-Nogueira I, Lourenco N, Borges JP, Vidinha P.
2013.
Development of antimicrobial Ion Jelly fibers. RSC Adv.. 3:24400-24405.: The Royal Society of Chemistry
AbstractWe report a method to obtain electrospun fibers based on ionic liquids and gelatin, exhibiting antimicrobial properties.
Neves, CS, Granadeiro CM, Cunha-Silva L, Ananias D, Gago S, Feio G, Carvalho PA, Eaton P, Balula SS, Pereira E.
2013.
Europium Polyoxometalates Encapsulated in Silica Nanoparticles Characterization and Photoluminescence Studies. European Journal of Inorganic Chemistry. :2877-2886., Number 16
Abstractn/a
Neves, CS, Granadeiro CM, Cunha-Silva L, Ananias D, Gago S, Feio G, Carvalho PA, Eaton P, Balula SS, Pereira E.
2013.
Europium Polyoxometalates Encapsulated in Silica Nanoparticles Characterization and Photoluminescence Studies. European Journal of Inorganic Chemistry. :2877-2886., Number 16
AbstractThe incorporation of europium polyoxometalates into silica nanoparticles can lead to a biocompatible nanomaterial with luminescent properties suitable for applications in biosensors, biological probes, and imaging. Keggin-type europium polyoxometalates Eu(PW11)x (x = 1 and 2) with different europium coordination environments were prepared by using simple methodologies and no expensive reactants. These luminescent compounds were then encapsulated into silica nanoparticles for the first time through the water-in-oil microemulsion methodology with a nonionic surfactant. The europium polyoxometalates and the nanoparticles were characterized by using several techniques [FTIR, FT-Raman, 31P magic angle spinning (MAS) NMR, and TEM/energy-dispersive X-ray spectroscopy (TEM-EDS), AFM, dynamic light scattering (DLS), and inductively coupled plasma MS (ICP-MS) analysis]. The stability of the material and the integrity of the europium compounds incorporated were also examined. Furthermore, the photoluminescence properties of the Eu(PW11)x@SiO2 nanomaterials were evaluated and compared with those of the free europium polyoxometalates. The silica surface of the most stable nanoparticles was successfully functionalized with appropriate organosilanes to enable the covalent binding of oligonucleotides.
Oliveira, FS, Pereiro AB, Araujo JM, Bernardes CE, Canongia Lopes JN, Todorovic S, Feio G, Almeida PL, Rebelo LP, Marrucho IM.
2013.
High ionicity ionic liquids (HIILs): comparing the effect of ethylsulfonate and ethylsulfate anions. Phys Chem Chem Phys. 15:18138-47., Number 41
AbstractThe subject of ionicity has been extensively discussed in the last decade, due to the importance of understanding the thermodynamic and thermophysical behaviour of ionic liquids. In our previous work, we established that ionic liquids' ionicity could be improved by the dissolution of simple inorganic salts in their milieu. In this work, a comparison between the thermophysical properties of two binary systems of ionic liquid + inorganic salt is presented. The effect of the ammonium thiocyanate salt on the ionicity of two similar ionic liquids, 1-ethyl-3-methylimidazolium ethylsulfonate and ethylsulfate, is investigated in terms of the related thermophysical properties, such as density, viscosity and ionic conductivity in the temperature range 298.15-323.15 K. In addition, spectroscopic (NMR and Raman) and molecular dynamic studies were conducted in order to better understand the interactions that occur at a molecular level. The obtained results reveal that although the two anions of the ionic liquid exhibit similar chemical structures, the presence of one additional oxygen in the ethylsulfate anion has a major impact on the thermophysical properties of the studied systems.