Ropio, I, Baptista AC, Nobre J, Correia J, Belo F, Taborda S, Faustino MBM, Borges JB, Kovalenko A, Ferreira I.
2018.
Cellulose paper functionalised with polypyrrole and poly(3,4-ethylenedioxythiophene) for paper battery electrodes. Organic Electronics. 62:530-535.
AbstractA simple process of commercial paper functionalisation via in situ polymerisation of conductive polymers onto cellulose fibres was investigated and applied as electrodes in paper-based batteries. The functionalisation involved polypyrrole (PPy) and Poly (3,4-ethylenedioxythiophene) (PEDOT) as conductive polymers with the process of functionalisation optimised for each polymer individually with respect to oxidant-to-monomer ratios and polymerisation times and temperature. Paper with conductivity values of 44 mS/cm was obtained by exposing the samples to pyrrole vapour for a period of 30 min at room temperature; however, polymerisation at temperatures of 40 °C lead to higher conductivity values to up 141 mS/cm. Consequently, functionalised PPy and PEDOT papers were applied as cathodes in batteries with Al foil anodes and commercial paper soaked in an electrolyte solution of NaCl.
Giannakidis, G, Gargiulo M, De Miglio R, Chiodi A, Seixas J, Simoes SG, Dias L, Gouveia J.
2018.
Challenges faced when addressing the role of cities towards a below 2-degree world. Limiting Global Warming to Well Below 2°C: Energy System Modelling and Policy Development. (
Giannakidis G., K. Karlsson, M. Labriet, B. Ó Gallachóir, Eds.).: Lecture Notes in Energy 64. Springer International publishing. Doi: 10.1007/978-3-319-74424-7
Mirante, F, Dias L, Silva M, Ribeiro SO, Corvo MC, de Castro B, Granadeiro CM, Balula SS.
2018.
Efficient heterogeneous polyoxometalate-hybrid catalysts for the oxidative desulfurization of fuels. Catalysis Communications. 104:1–8.: Elsevier
AbstractThe heterogenization of the highly active monovacant polyoxotungstate ([PW11O39]7 −, abbreviated as PW11) was achieved by preparing the corresponding long chain quaternary ammonium salt (ODA7PW11, ODA = CH3(CH2)17(CH3)3N). The complete cation exchange confers total heterogeneity to the monovacant catalyst while keeping its oxidative catalytic activity. In fact, the heterogeneous catalyst allowed for the complete desulfurization of a multicomponent model diesel (2000 ppm S) after 40 min of reaction, conciliating extraction (using BMIMPF6 solvent) and oxidation (ECODS process using H2O2 oxidant). The heterogeneous catalyst has shown a superior desulfurization performance when compared with the homogeneous quaternary ammonium TBAPW11 catalyst (TBA = (C4H9)4 N). Both hybrid catalysts have been successfully reused in consecutive ECODS cycles. Additionally, the long carbon chain cations provide a protective environment around the polyoxometalate allowing for ODA7PW11 to retain its heterogeneity and structure after the ECODS process.
Matos, R, Chaparro C, Silva JC, Valente M, Borges JP, Soares PIP.
2018.
Electrospun composite cellulose acetate/iron oxide nanoparticles non-woven membranes for magnetic hyperthermia applications. Carbohydrate polymers. 198:9-16.
AbstractIn the present work composite membranes were produced by combining magnetic nanoparticles (NPs) with cellulose acetate (CA) membranes for magnetic hyperthermia applications. The non-woven CA membranes were produced by electrospinning technique, and magnetic NPs were incorporated by adsorption at fibers surface or by addition to the electrospinning solution. Therefore, different designs of composite membranes were obtained. Superparamagnetic NPs synthesized by chemical precipitation were stabilized either with oleic acid (OA) or dimercaptosuccinic acid (DMSA) to obtain stable suspensions at physiological pH. The incorporation of magnetic NP into CA matrix was confirmed by scanning and transmission electron microscopy. The results showed that adsorption of magnetic NPs at fibers’ surface originates composite membranes with higher heating ability than those produced by incorporation of magnetic NPs inside the fibers. However, adsorption of magnetic NPs at fibers’ surface can cause cytotoxicity depending on the NPs concentration. Tensile tests demonstrated a reinforcement effect caused by the incorporation of magnetic NPs in the non-woven membrane.
Reckien, D, Heidrich O, Church J, Pietrapertos F, De Gregorio-Hurtado S, D'Alonzo V, Foley A, Simoes SG, Lorencová EK, Orruk H, Orrum K, Wejs A, Flacke J, Olazabal M, Geneletti D, Feliu E, Vasilier S, Nador C, Krook-Riekkola A, Matosović M, A. Fokaides P, I. Ioannou B, Flamos A, Spyridaki N.
2018.
How are cities planning to respond to climate change? Assessment of local climate plans from 885 cities in the EU-28 Journal of Cleaner Production. doi: 10.1016/j.jclepro.2018.03.220. 191:207-219.
Cidade, MT, Ramos DJ, Santos J, Calero N, Muñoz J, Borges JP.
2018.
Injectable hydrogels based on pluronic/water systems filled with alginate microparticles: Rheological characterization. Publisher Logo Conference Proceedings. 1981:020091.
AbstractIn this paper the rheological characterization of Pluronic/water systems filled with alginate microparticles is presented. The rheological characterization of the Pluronic/water systems allowed for the choice of the best Pluronic concentration taking into account its applications as injectable hydrogels for tissue repair. The effect on the rheological behavior of the addition of alginate microparticles, to be loaded with the drug, was analyzed and the maximum concentration of microparticles determined.
Beira, JM, Silva MP, Condesso M, Cosme P, Almeida PL, Corvo M, Sebastião PJ, Figueirinhas JL, de Pinho MN.
2018.
Molecular order and dynamics of water in hybrid cellulose acetate–silica asymmetric membranes. Molecular Physics. :1–8.: Taylor & Francis
AbstractIn this work 2H NMR spectroscopy and 1H NMR relaxometry and diffusometry were used to characterise water order and dynamics in cellulose acetate/silica asymmetric membranes. Two hydrated membranes were characterised allowing the identification of extra ordering of the water molecules and the presence in each membrane of up to two spectral components with different degrees of order and different T1 values. The mechanism behind this order increase was ascribed to the rapid exchange of the water molecules between the pore walls and its interior. T1 relaxometry dispersions allowed for the identification of the relevant mechanisms of pore-confined water motion, with rotations mediated by translational displacements (RMTD) as the dominant mechanism in the low frequency region. Using the RMTD low cut off frequency along with the in situ directly measured diffusion constant it was possible do determine characteristic lengths of correlated water motion in both membranes studied, which fall in ranges compatible with typical pore dimensions in similar membranes.
Braz, L, Grenha A, Corvo MC, Lourenço JP, Ferreira D, Sarmento B, da Costa ARM.
2018.
Synthesis and characterization of Locust Bean Gum derivatives and their application in the production of nanoparticles. Carbohydrate Polymers. 181:974–985.: Elsevier
AbstractThe development of LBG-based nanoparticles intending an application in oral immunization is presented. Nanoparticle production occurred by mild polyelectrolyte complexation, requiring the chemical modification of LBG. Three LBG derivatives were synthesized, namely a positively charged ammonium derivative (LBGA) and negatively charged sulfate (LBGS) and carboxylate (LBGC) derivatives. These were characterized by Fourier-transform infrared spectroscopy, elemental analysis, nuclear magnetic resonance spectroscopy, gel permeation chromatography, and x-ray diffraction. As a pharmaceutical application was aimed, a toxicological analysis of the derivatives was performed by both MTT test and LDH release assay.
Several nanoparticle formulations were produced using LBGA or chitosan (CS) as positively charged polymers, and LBGC or LBGS as negatively charged counterparts, producing nanoparticles with adequate properties regarding an application in oral immunization.
Branco, PS, Peixoto D, Figueiredo M, Malta G, Roma-Rodrigues C, Batista PV, Fernandes AR, Barroso S, Carvalho AL, Afonso CAM, Ferreira LM.
2018.
Synthesis, cytotoxicity evaluation in human cell lines and in vitro DNA interaction of a hetero arylidene-9(10H)-anthrone. European Journal of Organic Chemistry. :n/a–n/a.
AbstractA new and never yet reported hetero arylidene-9(10H)-anthrone structure (4) was unexpectedly isolated on reaction of 1,2-dimethyl-3-ethylimidazolium iodide (2) and 9-anthracenecarboxaldehyde (3) under basic conditions. Its structure was unequivocally attributed by X-ray crystallography. No cytotoxicity in human healthy fibroblasts and in two different cancer cell lines was observed indicating its applicability in biological systems. Compound 4 interacts with CT-DNA by intercalation between the adjacent base pairs of DNA with a high binding affinity (Kb = 2.0(± 0.20) x 105 M-1) which is 10x higher than that described for doxorubicin (Kb = 3.2 (±0.23) × 104 M-1). Furthermore, compound 4 quenches the fluorescence emission of GelRed-CT-DNA system with a quenching constant (KSV) of 3.3(±0.3) x 103 M-1 calculated by the Stern-Volmer equation.
Teixeira, LR, Dantas JM, Salgueiro CA, Cordas CM.
2018.
Thermodynamic and kinetic properties of the outer membrane cytochrome OmcF, a key protein for extracellular electron transfer in Geobacter sulfurreducens. Biochimica et Biophysica Acta (BBA) - Bioenergetics. 1859(10):1132-1137.
AbstractGene knock-out studies on Geobacter sulfurreducens have shown that the monoheme c-type cytochrome OmcF is essential for the extracellular electron transfer pathways involved in the reduction of iron and uranium oxy-hydroxides, as well as, on electricity production in microbial fuel cells. A detailed electrochemical characterization of OmcF was performed for the first time, allowing attaining kinetics and thermodynamic data. The heterogeneous electron transfer rate constant was determined at pH 7 (0.16 ± 0.01 cm s−1) indicating that the protein displays high electron transfer efficiency compared to other monoheme cytochromes. The pH dependence of the redox potential indicates that the protein has an important redox-Bohr effect in the physiological pH range for G. sulfurreducens growth. The analysis of the structures of OmcF allowed us to assign the redox-Bohr centre to the side chain of His47 residue and its pKa values in the reduced and oxidized states were determined (pKox = 6.73; pKred = 7.55). The enthalpy, entropy and Gibbs free energy associated with the redox transaction were calculated, pointing the reduced form of the cytochrome as the most favourable. The data obtained indicate that G. sulfurreducens cells evolved to warrant a down-hill electron transfer from the periplasm to the outer-membrane associated cytochrome OmcF.