Thalles Rafael Silva Rêgo

Mr. Thalles Rafael Silva Rêgo

Instituto de Macromoléculas Professora Eloisa Mano, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
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Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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10 June 2025 in Processes
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Journal Article
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Thalles Rafael Silva RêgoThalles Rafael Silva Rêgo
Thalles Rafael Silva Rêgo
ATAnna Lecticia Martinez Martinez Toledo
Anna Lecticia Martinez Martinez Toledo
MARCOS DIASMARCOS DIAS
MARCOS DIAS
The electrospinning technique can produce multifunctional polymeric devices by forming solid fibers from polymer solutions under a high-voltage electric field. Variations such as concentric needles yield core/shell fibers. This study evaluates the effects of applied voltage (12.5–20 kV) and tip-to-collector distance (12.5–20 cm) on the morphology and thermochemical behavior of PLGA/PVA fibers made by coaxial electrospinning compared with casting-produced membranes and monolithic fibers. Optimal coaxial fibers (597 ± 90 nm diameter) were produced at 15 cm/12.5 kV, exhibiting a well-defined core/shell structure (PVA core: ~100 nm; PLGA shell: ~50 nm) confirmed by laser scanning confocal (core solution labeled with fluorescein) and TEM. FTIR and TGA demonstrated nearly complete solvent removal in electrospun samples versus ~10% solvent retention in cast films. XRD analysis indicated that cast films (PLGAff) exhibited minimal crystallinity (Xc ≈ 0.1%), while electrospun PLGA (PLGAe) showed cold crystallization and higher crystallinity (Tcc ≈ 90.6 °C; Xc ≈ 2.45%). DSC detected two different Tg (≈43.2 °C and 52.8 °C) in the coaxial fibers, confirming distinct polymer domains with interfacial interactions. These results establish precise processing/structure relationships for defect-free coaxial fibers and provide fundamental design principles for hybrid systems in controlled drug delivery and tissue engineering applications.

1 November 2015 in Energy Procedia
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Journal Article
Open access
Ana Sofia GuimarãesAna Sofia Guimarães
Ana Sofia Guimarães
VFV.P. de Freitas
V.P. de Freitas
João DelgadoJoão Delgado
João Delgado
Thalles Rafael Silva RêgoThalles Rafael Silva Rêgo
Thalles Rafael Silva Rêgo
The analysis of moisture migration in building materials and elements is crucial for its behaviour knowledge also affecting its durability, waterproofing, degradation and thermal performance. Based on this breach it is intended to analyse the interface effect in the capillary process in ceramic brick. Ceramic brick is a common material in Portuguese exterior walls, where usually it has mortar joints. In the foremost cases, Portuguese exterior walls are multilayer walls with materials in perfect contact and/or with an air space. Knowing that, in this paper, an experimental research using samples to capillary tests are used considering four different cases: monolithic and three interfaces: perfect contact, air space and hydraulic continuity (mortar).Since a long time, moisture is one of the primary causes for the observed damage on the buildings envelope, increasing the importance of this research with the goal of controlling the real moisture migration process. This paper has two special purposes:(a) The analysis of ceramic brick capillarity coefficient without interfaces (monolithic) and with three different interfaces: perfect contact, air space and hydraulic continuity (mortar) and (b) The calculation of the hydric resistance in the interface that conditions the maximum flow transmitted FLUMAX. This value is an important input in numerical simulations with multilayer building components and is a parameter to be obtained experimentally.In the first weights the water front is lower than the interface position so it would be expected that the capillary coefficient, calculated for the first step, is not to much influenced by the interface. It is expected that the maximum flow transmitted – FLUMAX, in the three different interfaces, is lower to air space, higher to hydraulic continuity, being the perfect contact in the middl