A carregar...
Projeto de investigação
Sem título
Financiador
Autores
Publicações
Plasma-enabled growth of vertically oriented carbon nanostructures for AC line filtering capacitors
Publication . Bundaleska, N.; Felizardo, E.; Santhosh, N. M.; Upadhyay, K. K.; Bundaleski, N.; Teodoro, O. M. N. D.; Botelho do Rego, A. M.; Ferraria, A. M.; Zavašnik, J.; Cvelbar, U.; Abrashev, M.; Kissovski, J.; Mão de Ferro, A.; Gonçalves, B.; Alves, L. L.; Montemor, M. F.; Tatarova, E.; CeFITec – Centro de Física e Investigação Tecnológica; DF – Departamento de Física; North-Holland | Elsevier
Self-standing vertically oriented carbon nanostructures (VCNs) were synthesized using a large-scale microwave plasma under low-pressure conditions, employing methane as a carbon precursor. The influence of plasma operational and substrate conditions on nanostructure growth and morphology were systematically studied. Furthermore, post-synthesis N-doping of VCNs with nitrogen content of 2.4 at% N was achieved using an Ar-N2 microwave plasma. Plasma-enabled direct deposition of VCNs, both doped and un-doped, onto nickel foils has been accomplished. The assessment of the developed nanostructures as electrodes in high-frequency AC filtering capacitors, has demonstrated an overall capacitance of approximately 480 µF at 100 Hz, with a cut-off frequency of 4 kHz for a phase angle of −45°. The excellent electrochemical performance can be attributed to the appropriate structural and morphological properties peculiar for the directly deposited on nickel foil VCNs providing binder-free electrode fabrication, thus enhancing the electrode's conductivity and charge transfer kinetics. This plasma-enabled approach for electrode design on a large scale, coupled with excellent filtering performance, paves the way for many applications in high-frequency scenarios, offering an environmentally friendly alternative to conventional electrolytic capacitors.
Design of magnetic kappa-carrageenan-collagen bioinks for 3D bioprinting
Publication . Almeida, Duarte; Küppers, Freya; Gusmão, Afonso; Manjua, Ana C.; Ferreira, Catarina F.R.; Portugal, Carla A.M.; Silva, João C.; Sanjuan-Alberte, Paola; Ferreira, Frederico Castelo; LAQV@REQUIMTE; DQ - Departamento de Química; Springer
Bioprinting approaches are of great promise for tissue engineering applications as they allow the fabrication of constructs able to mimic native tissues’ mechanical and topographical features. Additional control over cells fate can be enhanced using stimuli-responsive materials, requiring the development of novel bioinks for this purpose. In this study, bioinks comprising κ-carrageenan, collagen, and magnetic nanoparticles were designed for 3D bioprinting applications. The characterization of this material was performed, where mechanical compressive tests yielded Young’s moduli ranging from 8.25 to 18.4 kPa. Rheological assessments also revealed the shear-thinning behavior of the bioinks and a temperature-dependent gelation. The capability of these bioinks to produce 3D constructs by extrusion bioprinting was established through the printability evaluation and the development of complex structures, supporting the viability and proliferation of mesenchymal stromal cells (MSCs). Finally, as proof-of-concept, it was observed that the secretome of bioprinted MSCs stimulated with an external magnetic field of 80 mT was able to increase the number of tubes formed by human umbilical vein endothelial cells.
Unidades organizacionais
Descrição
Palavras-chave
Contribuidores
Financiadores
Entidade financiadora
Fundação para a Ciência e a Tecnologia
Programa de financiamento
Concurso de avaliação no âmbito do Programa Plurianual de Financiamento de Unidades de I&D (2017/2018) - Financiamento Base
Número da atribuição
UIDB/04565/2020