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Modifying fish gelatin electrospun membranes for biomedical applications: cross...
Padrão, Jorge; Silva, João P.; Rodrigues, Ligia R.; Dourado, Fernando; Lanceros-Mendez, Senentxu; Sencadas, VitorDevelopment of suitable membranes is a fundamental requisite for tissue and biomedical engineering applications. This work presents fish gelatin random and aligned electrospun membranes cross-linked with glutaraldehyde (GA). It was observed that the fiber average diameter and the morphology is not influenced by the GA exposure time and presents fibers with an average diameter around 250 nm. Moreover, when the g...
Kit “Energia, Ambiente e Sustentabilidade”, uma Proposta para a Promoção da Edu...
Oliveira, Joana; Lanceros-Méndez, Senentxu; Neves, Luísa; Santos, Júlio Gonçalves dosA educação científica encontra-se profundamente intrincada nas dimensões económica, ambiental e social do desenvolvimento. As ações a desenvolver devem visar a formação de cientistas, técnicos e cidadãos esclarecidos e comprometidos com formas de viver e pensar sustentáveis. No entanto, o que se verifica em muitos países africanos, nomeadamente na Guiné-Bissau, é que o ensino das ciências se baseia na memorizaç...
Influence of electrospinning parameters on Poly(hydroxybutyrate) electrospun me...
Correia, Daniela M.; Ribeiro, Clarisse; Ferreira, José C. C.; Botelho, Gabriela; Gomez Ribelles, Jose Luis; Lanceros-Mendez, Senentxu; Sencadas, VitorPoly(hydroxybutyrate) (PHB) obtained from sugar cane was dissolved in a blend of chloroform and dimethylformamide (DMF) and electrospun at 40 ºC. By adding DMF to the solution, the electrospinning process for the PHB polymer becomes more stable, allowing complete polymer crystallization during the jet travelling between the tip and the grounded collector. The influence of processing parameters on fiber size and...
Processing and characterization of alpha-elastin electrospun membranes
Araujo, Joana; Padrão, Jorge; Silva, João P.; Dourado, Fernando; Correia, Daniela M.; Botelho, Gabriela; Gomez Ribelles, Jose LuisElastin isolated from fresh bovine ligaments was dissolved in a mixture of 1,1,1,3,3,3-Hexafluoro-2-propanol and water and electrospun into fiber membranes under different processing conditions. Fiber mats of randomly and aligned fibers were obtained with fixed and rotating ground collectors and fibrils were composed by thin ribbons whose width depends on electrospinning conditions; fibrils with 721 nm up to 2....
Mechanical, electrical and electro-mechanical properties of thermoplastic elast...
Costa, Pedro; Silva, Jaime; Sencadas, Vitor; Simões, Ricardo; Viana, Julio C.; Lanceros-Mendez, SenentxuComposites of styrene–butadiene–styrene (SBS) block copolymer with multiwall carbon nanotubes were processed by solution casting to investigate the influence of filler content, the different ratios of styrene/butadiene in the copolymer and the architecture of the SBS matrix on the electrical, mechanical and electro-mechanical properties of the composites. It was found that filler content and elastomer matrix archi...
Electrospun silk-elastin-like fiber mats for tissue engineering applications
Machado, Raul; Costa, André; Sencadas, Vitor; Garcia-Arevalo, Carmen; Costa, Carlos M.; Gomes, Andreia; Lanceros-Mendez, SenentxuProtein-based polymers are present in a wide variety of organisms fulfilling structural and mechanical roles. Advances in protein engineering and recombinant DNA technology allow the design and production of recombinant protein-based polymers (rPBPs) with an absolute control of its composition. Although the application of recombinant proteins as biomaterials is still an emerging technology, the possibilities ar...
Modeling Carbon Nanotube Electrical Properties in CNT/Polymer Composites
Silva, J.; Simões, Ricardo; Lanceros-Mendez, SenentxuIn this work it is demonstrated that the capacitance between two cylinders increases with the rotation angle and it has a fundamental influence on the composite dielectric constant. The dielectric constant is lower for nematic materials than for isotropic ones and this can be attributed to the effect of the filler alignment in the capacitance. The effect of aspect ratio in the conductivity is also studied in th...
Multi-scale modeling of the mechanical behavior of polymer-based materials
Araújo, Miguel Carvalho; Martins, J. P.; Mirkhalaf, Mohsen; Lanceros-Mendez, Senentxu; Pires, Francisco; Simões, RicardoPolymers have become the reference material for high reliability and performance applications. In this work, a multi-scale approach is proposed to investigate the mechanical properties of polymeric based material under strain. To achieve a better understanding of phenomena occurring at the smaller scales, a coupling of a Finite Element Method (FEM) and Molecular Dynamics (MD) modeling in an iterative procedure ...
Electro-mechanical properties of triblock copolymer styrene-butadiene-styrene /...
Costa, Pedro; Ferreira, Armando; Sencadas, Vitor; Viana, Julio C.; Lanceros-Mendez, SenentxuThermoplastic elastomer/carbon nanotube composites are studied for sensor applications due to their excellent mechanical and electrical properties. Piezoresisitive properties of tri-block copolymer styrene-butadiene-styrene (SBS)/ carbon nanotubes (CNT) prepared by solution casting have been investigated. Young modulus of the SBS/CNT composites increases with the amount of CNT filler content present in the sam...
Effect of fiber alignment in gelled electrospun membranes based on poly(vinylid...
Costa, Carlos M.; Nunes-Pereira, João; Sencadas, Vitor; Silva, M. Manuela; Lanceros-Mendez, SenentxuBattery separators based on electrospun membranes of poly(vinylidene fluoride) (PVDF) have been prepared in order to study the effect of fiber alignment on the performance and characteristics of the membrane. The prepared membranes show an average fiber diameter of 272 nm and a degree of porosity of 87 %. The gel polymer electrolytes are prepared by soaking the membranes in the electrolyte solution. The alignment ...
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