92 documents found, page 1 of 10
Bimetallic-zeolite nanomaterials as catalysts for degradation of azorubine dye ...
Mrabet, Imane El; Santos, Bebiana L. C.; Tanji, Karim; Rombi, Elisabetta; Parpot, Pier; Fonseca, A. M.; Zaitan, Hicham; Neves, Isabel C.Solutions containing equal concentrations of each metal ion pair (Zn/Fe, Co/Fe, Ni/Fe) were simultaneously added to the zeolite NaY using the ion-exchange method. The resulting bimetallic-zeolites were used as heterogeneous catalysts for the Fenton-like reaction for azorubine dye degradation. The optimization of the reaction parameters was assessed using the Box-Behnken design by studying the influence of H2O2 ...
Antimicrobial agents based on metal-ion zeolite materials: a multivariate appro...
Guedes, Joana; Gonçalves, Diogo B.; Rodrigues, Catarina F.; Parpot, Pier; Fonseca, A. M.; Almeida Aguiar, Cristina; Neves, Isabel C.Bacteria are susceptible to zeolites doped with metal ions. Although the complete mode of action remains unclear, it is widely accepted that metal ions kill bacteria by inducing the production of reactive oxygen species (ROS), which are detrimental to microbial life processes. In this study, two zeolite structures, MFI and LTA, were selected as hosts for the preparation of various metal-ion zeolite materials, w...
From waste to value: electrocatalytic reduction of nitrate into ammonia at mono...
Ferreira, Marta; Kuzniarska-Biernacka, Iwona; Soares, Olívia S. G. P.; Figueiredo, José L.; Pereira, Manuel F. R.; Neves, Isabel C.; Fonseca, A. M.The electrochemical transformation of nitrate ions into ammonia (NH3), which ranks among the most widely employed chemicals globally, using mono (Pd, Pt) and bimetallic catalysts (Pd-Cu, Pt-Cu, Ru-Cu) supported on carbon nanotubes (CNT) was studied in acidic medium. The higher conversion and best selectivity towards NH3 corresponding, respectively, to 88 and 80% were found for Pt_CNT modified electrode, with an...
Development and optical characterisation of agarose-based phantoms mimicking bi...
Fernandes, Filipa Gracinda Silva; Pereira, Mário R.; Soares, Delfim; Fonseca, A. M.; Costa, Daniel; Silva, Filipe Samuel; Sousa, NunoSearching for materials that accurately mimic the optical properties of biological tissues is essential, particularly for transcranial photobiomodulation (PBM) research, where it is necessary to comprehend how light propagates through the head tissues. In this research, we characterised, in the 500-1200 nm range, the transmittance spectra of porcine tissues (skin, muscle, cranium, brain, and cerebellum) and dif...
Machine learning-assisted optimization of drug combinations in zeolite-based de...
Bertão, Ana Raquel; Teixeira, Filipe; Ivasiv, Viktoriya; Parpot, Pier; Almeida Aguiar, Cristina; Fonseca, A. M.; Bañobre-López, Manuel; Baltazar, FátimaTwo independent artificial neural network (ANN) models were used to determine the optimal drug combination of zeolite-based delivery systems (ZDS) for cancer therapy. The systems were based on the NaY zeolite using silver (Ag+) and 5-fluorouracil (5-FU) as antimicrobial and antineoplastic agents. Different ZDS samples were prepared, and their characterization indicates the successful incorporation of both pharm...
Sustainable fluorescent dye-faujasite zeolite systems as tools for cancer bioim...
Bertão, Ana R.; Güney, Orhan; Costa, Marta; Fontão, Patrícia; Martinho, Olga; Costa, Susana P. G.; Fonseca, A. M.; Soares, Olívia S. G. P.The use of fluorescent nanoparticles for biological and medical applications has attracted great attention due to their several advantages compared to conventional fluorescent dyes. However, there is also a need for sustainable and versatile alternatives, alongside the streamlining of complex synthesis or preparations. In this work, we study the potential of the faujasite zeolite structure to encapsulate dye mo...
Optimization of iron-ZIF-8 catalysts for degradation of tartrazine in water by ...
Assila, Ouissal; Vilaça, Natália; Bertão, Ana R.; Fonseca, A. M.; Parpot, Pier; Soares, Olívia S. G. P.; Pereira, Manuel F. R.; Baltazar, FátimaOptimization of iron zeolitic imidazole framework-8 (FeZIF-8) nanoparticles, as heterogeneous catalysts, were synthesized and evaluated by the Fenton-like reaction for to degrade tartrazine (Tar) in aqueous environment. To achieve this, ZIF-8 nanoparticles were modified with different iron species (Fe2+ or Fe3O4), and subsequently assessed through the Fenton-like oxidation. The effect of different parameters su...
Degradation of pollutants in water by Fenton-like oxidation over LaFe-catalysts...
Assila, Ouissal; Barros, Óscar; Fonseca, A. M.; Parpot, Pier; Soares, Olívia S. G. P.; Pereira, Manuel F. R.; Zerrouq, Farid; Kherbeche, AbdelhakThe effect of different parameters such as temperature, type of catalyst and hydrogen peroxide (H2O2) concentration on the degradation of pollutants in water by Fenton-like oxidation was studied by using the Box-Behnken design (BBD), an effective statistical model to design the experiments. Concerning the heterogeneous catalysts, three bimetallic catalysts with lanthanum (La) and iron (Fe) ion-exchanged into ze...
Raw clays from Morocco for degradation of pollutants by Fenton-like reaction fo...
Assila, Ouissal; Bencheqroun, Zineb; Rombi, Elisabetta; Valente, Teresa Maria Fernandes; Braga, Amália S.; Zaitan, Hicham; Kherbeche, AbdelhakThree raw clays from Morocco were used as heterogeneous catalysts for Fenton-like oxidation of organic pollutants in water. The selected pollutants were two dyes used in the textile industry, Congo Red (CR) and Tartrazine (Tar, known also as a food coloring compound, E102) and Caffeine (Caf), a stimulant drug present in popular beverages such as coffee and tea, commonly used in Morocco. Two different processes ...
The role of Portuguese democratisation in the Socialist International’s initiat...
Fonseca, A. M.The purpose of this chapter is to analyse the role that the Socialist International (SI) and Western European Socialist and Social-democratic parties had during the Portuguese democratisation process. Simultaneously, we also wish to understand how Iberian democratic transitions impacted on the modus-operandi of the SI in other areas of the world, namely in Latin America. However, it is impossible to analyse the...