134 results on '"Verónica De Zea Bermudez"'
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2. Antifungal Susceptibility Assessment of Innovative and Non-Conventional Lime Mortars Incorporating Almond-Shell Powder Bio-Waste Subjected to Particle-Dispersion Technique
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Alexandre Jerónimo, Mafalda Loureiro, Mariana Fernandes, Verónica De Zea Bermudez, and Ana Briga-Sá
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lime mortars ,almond-shell powder ,particle-dispersion techniques ,fungal susceptibility ,wettability ,mechanical properties ,Technology ,Electrical engineering. Electronics. Nuclear engineering ,TK1-9971 ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Microscopy ,QH201-278.5 ,Descriptive and experimental mechanics ,QC120-168.85 - Abstract
A favorable environment for fungi colonization in building materials’ surfaces can emerge when certain hygrothermal conditions occur. Thus, reducing fungal growth susceptibility is of major interest. Furthermore, if the integration of bio-wastes is performed in parallel with the development of innovative materials for this purpose, a more sustainable and environmentally friendly material can be obtained. In this study, the fungal susceptibility of lime mortars incorporating almond-shell powder (ASP) microparticles (2 and 4%, wt.–wt. in relation to the binder content) was evaluated. The particle-dispersion technique was employed to prepare the bio-waste introduced in the mixtures. The fungal susceptibility of ASP samples was compared with nanotitania (n-TiO2) with recognized antifungal properties. Mechanical strength, water absorption, and wettability tests were also performed for a better characterization of the composites. Although the addition of 2% ASP led to mechanical properties reduction, an increase in the compressive and flexural strength resulted for 4% of the ASP content. Difficulties in fungal growth were observed for the samples incorporating ASP. No fungal development was detected in the mortar with 2% of ASP, which may be correlated with an increase in the surface hydrophobic behavior. Furthermore, mortars with ASP revealed a reduction in water absorption by capillarity ability, especially with 4% content, suggesting changes in the microstructure and pore characteristics. The results also demonstrated that an improvement in the physical and mechanical properties of the lime mortars can be achieved when ASP microparticles are previously subjected to dispersion techniques.
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- 2024
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3. Hydrogels Based on Natural Polymers Loaded with Bentonite and/or Halloysite: Composition Impact on Spectroscopic, Thermal, and Swelling Properties
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Rodrigo César Sabadini, Mariana Fernandes, Verónica de Zea Bermudez, Agnieszka Pawlicka, and Maria Manuela Silva
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hydrogels ,nanocomposites ,gellan gum ,starch ,bentonite ,halloysite ,Organic chemistry ,QD241-441 - Abstract
Hydrogels are characterized by their property of absorbing and releasing a high content of water and water-based liquids; thus, they can be applied in agriculture as controlled-release water and fertilizer products. The focus of this research was efficient and low-cost natural polymer-based hydrogels obtained by crosslinking gellan gum (GGLA) and starch (ST) with acetic acid (CA) and loading them with either bentonite (BET) and/or halloysite (HAL). The hydrogels were obtained by mixing 100, 75, 50, 25, and 0 wt.% of GGLA with 0, 25, 50, 75, and 100 wt.% ST water solutions. To obtain the networks, they were crosslinked with 10, 5, and 2 wt.% of CA and loaded with 2, 5, and 10 wt.% of BET and/or HAL. The samples were analyzed by infrared spectroscopy (FTIR), differential scanning calorimetry (DSC), their swelling in water, and the state of bound water properties. The results of these analyses point to the formation of a polymeric network with a decomposition temperature of >250 °C, and tailorable swelling properties that vary between 3 and 77, depending on the hydrogel composition. In summary, GGLA-ST-BET/HAL hydrogels are a good option for eco-friendly agriculture materials.
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- 2023
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4. Leaf surfaces and neolithization - the case of Arundo donax L
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Sílvia C. Nunes, Ana P. Gomes, Paulo Nunes, Mariana Fernandes, Ana Maia, Eunice Bacelar, João Rocha, Rebeca Cruz, Aline Boatto, Ajith P. Ravishankar, Susana Casal, Srinivasan Anand, Verónica de Zea Bermudez, and António L. Crespí
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A. donax L. leaf ,environmental adaptation ,wax composition ,hydrophobicity ,optical properties ,neolithization ,Plant culture ,SB1-1110 - Abstract
Arundo donax L. (Arundinoideae subfamily, Poaceae family) is a sub-tropical and temperate climate reed that grows in arid and semi-arid environmental conditions, from eastern China to the Mediterranean basin, suggesting potential adaptations at the epicuticular level. A thorough physical-chemical examination of the adaxial and abaxial surfaces of A. donax leaf was performed herein in an attempt to track such chemophenetic adaptations. This sort of approach is of the utmost importance for the current debate about the hypothetical invasiveness of this species in the Mediterranean basin versus its natural colonization along the Plio-Pleistocene period. We concluded that the leaf surfaces contain, apart from stomata, prickles, and long, thin trichomes, and silicon-rich tetralobate phytolits. Chemically, the dominating elements in the leaf ashes are oxygen and potassium; minor amounts of calcium, silicon, magnesium, phosphorous, sulphur, and chlorine were also detected. In both surfaces the epicuticular waxes (whose density is higher in the adaxial surface than in the abaxial surface) form randomly orientated platelets, with irregular shape and variable size, and aggregated rodlets with variable diameter around the stomata. In the case of green mature leaves, the dominating organic compounds of the epicuticular waxes of both surfaces are triterpenoids. Both surfaces feature identical hydrophobic behaviour, and exhibit the same total transmittance, total reflectance, and absorption of incident light. The above findings suggest easy growth of the plant, remarkable epidermic robustness of the leaf, and control of water loss. These chemophenetic characteristics and human influence support a neolithization process of this species along the Mediterranean basin.
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- 2022
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5. Vicariance Between Cercis siliquastrum L. and Ceratonia siliqua L. Unveiled by the Physical–Chemical Properties of the Leaves’ Epicuticular Waxes
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Rui F. P. Pereira, João Rocha, Paulo Nunes, Tânia Fernandes, Ajith P. Ravishankar, Rebeca Cruz, Mariana Fernandes, Srinivasan Anand, Susana Casal, Verónica de Zea Bermudez, and António L. Crespí
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Cercidoideae ,Caesalpinoideae ,Mediterranean basin ,epicuticular waxes ,wettability ,optical properties ,Plant culture ,SB1-1110 - Abstract
Classically, vicariant phenomena have been essentially identified on the basis of biogeographical and ecological data. Here, we report unequivocal evidences that demonstrate that a physical–chemical characterization of the epicuticular waxes of the surface of plant leaves represents a very powerful strategy to get rich insight into vicariant events. We found vicariant similarity between Cercis siliquastrum L. (family Fabaceae, subfamily Cercidoideae) and Ceratonia siliqua L. (family Fabaceae, subfamily Caesalpinoideae). Both taxa converge in the Mediterranean basin (C. siliquastrum on the north and C. siliqua across the south), in similar habitats (sclerophyll communities of maquis) and climatic profiles. These species are the current representation of their subfamilies in the Mediterranean basin, where they overlap. Because of this biogeographic and ecological similarity, the environmental pattern of both taxa was found to be very significant. The physical–chemical analysis performed on the epicuticular waxes of C. siliquastrum and C. siliqua leaves provided relevant data that confirm the functional proximity between them. A striking resemblance was found in the epicuticular waxes of the abaxial surfaces of C. siliquastrum and C. siliqua leaves in terms of the dominant chemical compounds (1-triacontanol (C30) and 1-octacosanol (C28), respectively), morphology (intricate network of randomly organized nanometer-thick and micrometer-long plates), wettability (superhydrophobic character, with water contact angle values of 167.5 ± 0.5° and 162 ± 3°, respectively), and optical properties (in both species the light reflectance/absorptance of the abaxial surface is significantly higher/lower than that of the adaxial surface, but the overall trend in reflectance is qualitatively similar). These results enable us to include for the first time C. siliqua in the vicariant process exhibited by C. canadensis L., C. griffithii L., and C. siliquastrum.
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- 2022
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6. Luminescent Poly(vinylidene fluoride)‐Based Inks for Anticounterfeiting Applications
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Daniela Maria Correia, Rita Polícia, Nelson Pereira, Carmen Rial Tubio, Marita Cardoso, Gabriela Botelho, Rute A. S. Ferreira, Senentxu Lanceros-Méndez, and Verónica de Zea Bermudez
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anticounterfeiting ,europium complexes ,luminescent ionic liquids ,luminescent security inks ,PVDF ,Applied optics. Photonics ,TA1501-1820 ,Optics. Light ,QC350-467 - Abstract
Counterfeiting is a global ever‐growing problem of immense magnitude that represents a menace to security, economy, and health at a worldwide level. Herein, a new luminescent security ink composed of poly(vinylidene fluoride) (PVDF) and the home‐made ionic liquid (IL) 1‐butyl‐3‐methylimidazolium tetra(thenoyltrifluoroacetonato)europate(III) ([Bmim][Eu(tta)4]) is reported. The optimized PVDF/[Bmim][Eu(tta)4] composite is processed by the doctor blade method as a micrometer‐thick film invisible under white light, with porous texture. The material exhibits high thermal stability, high chemical stability (inertness with respect to ethanol), high photostability, and intense red emission when excited with long UV radiation (365 nm) with a maximum quantum yield value of 0.10 ± 0.01. A test of the PVDF/[Bmim][Eu(tta)4] ink screen‐printed on a medical N95 protection mask performed under irradiation with white light and with a commercial 365 nm LED demonstrates its suitability to combat fraud. The exciting possibilities offered by PVDF/luminescent IL pair in terms of chemical modification of PVDF (copolymerization or functionalization) and IL (cation type/lanthanide ion/ligand type) for the tuning of the ink properties allow envisaging the production of tailor‐made tri‐ or biluminescent security inks, for authentication purposes.
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- 2022
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7. Advanced hybrid nanomaterials
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Andreas Taubert, Fabrice Leroux, Pierre Rabu, and Verónica de Zea Bermudez
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colloidal chemistry ,environmental remediation ,hybrid nanomaterials ,nanocomposite ,nanofillers ,nanomedicine ,nanostructures ,polymer fillers ,pore templating ,smart materials ,Technology ,Chemical technology ,TP1-1185 ,Science ,Physics ,QC1-999 - Published
- 2019
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8. Sol-Gel Derived Di-Ureasil Based Ormolytes for Electrochromic Devices
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Paulo Joaquim Nunes, Rui Francisco Pinto Pereira, Sónia Pereira, Maria Manuela Silva, Elvira Fortunato, Verónica de Zea Bermudez, and Mariana Fernandes
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sol-gel ,di-ureasil electrolytes ,lithium tetrafluoroborate ,1-butyl-3-methylimidazolium chloride ,electrochromic devices ,Technology - Abstract
Two di-ureasils incorporating oxyethylene segments with average molecular weights Y = 600 and 900 g mol−1, prepared by the sol-gel method, and doped with the ionic liquid 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) and lithium tetrafluoroborate (LiBF4) salt were prepared. The as-obtained films are translucent, flexible, and hydrophobic, and have a low level of nanoscale surface roughness. The ionic conductivity values exhibited by an optimized sample are 8.10 × 10−5 and 2.8 × 10−4 S cm−1 at room temperature and 55 °C, respectively. The main goal of the work was to employ the electrolytes in prototype electrochromic devices (ECDs) with the [glass/a-IZO/a-WO3/d-U(Y)LiBF4-[Bmim]Cl/c-NiO/a-IZO/glass], noted as ECD1 for Y = 600 and ECD2 for Y = 900, where a-WO3 and c-NiO stand for amorphous tungsten oxide and crystalline nickel oxide, respectively. At 555 nm the ECD1 device exhibited the highest coloration efficiency for coloring (CEin = −420.621 cm2·C−1), the highest optical density value (∆(OD) = 0.13) and good cycling stability. In this article, the results of a preliminary evaluation of hybrid electrolytes, produced by a sol-gel process, as multi-functional components in prototype electrochromic devices are reported.
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- 2022
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9. β-Ketoenamine Covalent Organic Frameworks—Effects of Functionalization on Pollutant Adsorption
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Tiago F. Machado, Filipa A. Santos, Rui F. P. Pereira, Verónica de Zea Bermudez, Artur J. M. Valente, M. Elisa Silva Serra, and Dina Murtinho
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covalent organic frameworks ,β-ketoenamine ,adsorption ,methylene blue ,methyl orange ,heavy metals ,Organic chemistry ,QD241-441 - Abstract
Water pollution due to global economic activity is one of the greatest environmental concerns, and many efforts are currently being made toward developing materials capable of selectively and efficiently removing pollutants and contaminants. A series of β-ketoenamine covalent organic frameworks (COFs) have been synthesized, by reacting 1,3,5-triformylphloroglucinol (TFP) with different C2-functionalized and nonfunctionalized diamines, in order to evaluate the influence of wall functionalization and pore size on the adsorption capacity toward dye and heavy metal pollutants. The obtained COFs were characterized by different techniques. The adsorption of methylene blue (MB), which was used as a model for the adsorption of pharmaceuticals and dyes, was initially evaluated. Adsorption studies showed that –NO2 and –SO3H functional groups were favorable for MB adsorption, with TpBd(SO3H)2-COF [100%], prepared between TFP and 4,4′-diamine- [1,1′-biphenyl]-2,2′-disulfonic acid, achieving the highest adsorption capacity (166 ± 13 mg g−1). The adsorption of anionic pollutants was less effective and decreased, in general, with the increase in –SO3H and –NO2 group content. The effect of ionic interactions on the COF performance was further assessed by carrying out adsorption experiments involving metal ions. Isotherms showed that nonfunctionalized and functionalized COFs were better described by the Langmuir and Freundlich sorption models, respectively, confirming the influence of functionalization on surface heterogeneity. Sorption kinetics experiments were better adjusted according to a second-order rate equation, confirming the existence of surface chemical interactions in the adsorption process. These results confirm the influence of selective COF functionalization on adsorption processes and the role of functional groups on the adsorption selectivity, thus clearly demonstrating the potential of this new class of materials in the efficient and selective capture and removal of pollutants in aqueous solutions.
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- 2022
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10. Electrochromic Device Composed of a Di-Urethanesil Electrolyte Incorporating Lithium Triflate and 1-Butyl-3-Methylimidazolium Chloride
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Maria Cristina Gonçalves, Rui F. P. Pereira, Raquel Alves, Sílvia C. Nunes, Mariana Fernandes, Helena M. R. Gonçalves, Sónia Pereira, M. Manuela Silva, Elvira Fortunato, Rosa Rego, and Verónica de Zea Bermudez
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di-urethanesil ,sol-gel ,lithium triflate ,1-butyl-3-methylimidazolium chloride ,electrochromic device ,Technology - Abstract
A di-urethane cross-linked poly(oxyethylene)/silica hybrid matrix [di-urethanesil, d-Ut(600)], synthesized by the sol-gel process, was doped with lithium triflate (LiCF3SO3) and the 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) ionic liquid. The as-produced xerogel film is amorphous, transparent, flexible, homogeneous, hydrophilic, and has low nanoscale surface roughness. It exhibits an ionic conductivity of 3.64 × 10–6 and 5.00 × 10–4 S cm–1 at 21 and 100°C, respectively. This material was successfully tested as electrolyte in an electrochromic device (ECD) with the glass/ITO/a-WO3/d-Ut(600)10LiCF3SO3[Bmim]Cl/c-NiO/ITO/glass configuration, where a-WO3 and c-NiO stand for amorphous tungsten oxide and crystalline nickel oxide, respectively. The device demonstrated attractive electro-optical performance: fast response times (1–2 s for coloring and 50 s for bleaching), good optical memory [loss of transmittance (T) of only 41% after 3 months, at 555 nm], four mode modulation [bright mode (+3.0 V, T = 77% at 555 nm), semi-bright mode (−1.0 V, T = 60% at 555 nm), dark mode (−1.5 V, T = 38 % at 555 nm), and very dark mode (−2.0 V, T = 11% and −2.5 V, T = 7% at 555 nm)], excellent cycling stability denoting improvement with time, and high coloration efficiency [CEin = −6727 cm2 C–1 (32th cycle) and CEout = +2794 cm2 C–1 (480th cycle), at 555 nm].
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- 2020
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11. Ionic Liquid-Assisted Synthesis of Mesoporous Silk Fibroin/Silica Hybrids for Biomedical Applications
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Rui F. P. Pereira, Kerstin Zehbe, Christina Günter, Tiago dos Santos, Sílvia C. Nunes, Filipe A. Almeida Paz, Maria M. Silva, Pedro L. Granja, Andreas Taubert, and Verónica de Zea Bermudez
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Chemistry ,QD1-999 - Published
- 2018
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12. Bombyx mori silk/titania/gold hybrid materials for photocatalytic water splitting: combining renewable raw materials with clean fuels
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Stefanie Krüger, Michael Schwarze, Otto Baumann, Christina Günter, Michael Bruns, Christian Kübel, Dorothée Vinga Szabó, Rafael Meinusch, Verónica de Zea Bermudez, and Andreas Taubert
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Bombyx mori silk ,gold ,photocatalytic water splitting ,titania ,Technology ,Chemical technology ,TP1-1185 ,Science ,Physics ,QC1-999 - Abstract
The synthesis, structure, and photocatalytic water splitting performance of two new titania (TiO2)/gold(Au)/Bombyx mori silk hybrid materials are reported. All materials are monoliths with diameters of up to ca. 4.5 cm. The materials are macroscopically homogeneous and porous with surface areas between 170 and 210 m2/g. The diameter of the TiO2 nanoparticles (NPs) – mainly anatase with a minor fraction of brookite – and the Au NPs are on the order of 5 and 7–18 nm, respectively. Addition of poly(ethylene oxide) to the reaction mixture enables pore size tuning, thus providing access to different materials with different photocatalytic activities. Water splitting experiments using a sunlight simulator and a Xe lamp show that the new hybrid materials are effective water splitting catalysts and produce up to 30 mmol of hydrogen per 24 h. Overall the article demonstrates that the combination of a renewable and robust scaffold such as B. mori silk with a photoactive material provides a promising approach to new monolithic photocatalysts that can easily be recycled and show great potential for application in lightweight devices for green fuel production.
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- 2018
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13. Erratum: Development of Poly(l-Lactic Acid)-Based Bending Actuators. Polymers 2020, 12, 1187
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Daniela M. Correia, Liliana C. Fernandes, Bárbara D. D. Cruz, Gabriela Botelho, Verónica de Zea Bermudez, and Senentxu Lanceros-Méndez
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n/a ,Organic chemistry ,QD241-441 - Abstract
The authors wish to make a change to their published paper [...]
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- 2020
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14. Development of Poly(l-Lactic Acid)-Based Bending Actuators
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Daniela M. Correia, Liliana C. Fernandes, Bárbara D.D. Cruz, Gabriela Botelho, Verónica de Zea Bermudez, and Senentxu Lanceros-Méndez
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PLLA ,ionic liquid ,composites ,degree of crystallinity ,thermal treatments ,Organic chemistry ,QD241-441 - Abstract
This work reports on the development of bending actuators based on poly(l-lactic acid) (PLLA)/ionic liquid (IL) blends, through the incorporation of 40% wt. of the 1-ethyl-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][TFSI]) IL. The films, obtained by solvent casting at room temperature and 50 °C, were subjected to several post-thermal treatments at 70, 90, 120 and 140 °C, in order to modify the crystallinity of the films. The influence of the drying temperature and of [Emim][TFSI] blending on the morphological, structural, mechanical and electrical properties of the composite materials were studied. The IL induced the formation of a porous surface independently of the processing conditions. Moreover, the [Emim][TFSI] dopant and the post-thermal treatments at 70 °C promoted an increase of the degree of crystallinity of the samples. No significant changes were observed in the degree of crystallinity and Young Modulus for samples with thermal treatment between 70 and 140 °C. The viability of the developed high ionic conductive blends for applications as soft actuators was evaluated. A maximum displacement of 1.7 mm was achieved with the PLLA/[Emim][TFSI] composite prepared at 50 °C and thermally treated at 140 °C, for an applied voltage of 10 Vpp, at a frequency of 100 mHz. This work highlights interesting avenues for the use of PLLA in the field of actuators.
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- 2020
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15. Nanofluid Based on Carbon Dots Functionalized with Ionic Liquids for Energy Applications
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Helena M. R. Gonçalves, Susana A. F. Neves, Abel Duarte, and Verónica de Zea Bermudez
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nanofluids ,carbon dots ,ionic liquids ,electrolytes ,energy applications ,Technology - Abstract
The development of materials that can help overcome the current limitations in energy storage and consumption is a pressing need. Recently, we developed non-Newtonian nanofluids based on non-toxic, carbon nanoparticles (NPs), carbon dots (Cdots) functionalized with ionic liquids. Here, we wanted to prove that these new nanofluids are, not only interesting as possible electrolytes, but also as new organic/inorganic hybrid separators. As such, we developed an entrapment method using poly(vinyl alcohol) (PVA). Indeed, the highly conductive Cdots were successfully retained inside the membrane even upon the application of several wetting/drying cycles. Moreover, the morphological characteristics did not change upon wetting/drying cycles and remained constant for more than four months. These nanofluids could be an interesting approach to tackle some of the current problems in the fields of solid-state batteries, and energy storage, among others.
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- 2020
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16. Luminescent Electrochromic Devices for Smart Windows of Energy-Efficient Buildings
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Mariana Fernandes, Vânia Freitas, Sónia Pereira, Rita Leones, Maria Manuela Silva, Luís D. Carlos, Elvira Fortunato, Rute A. S. Ferreira, Rosa Rego, and Verónica de Zea Bermudez
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poly(ε-caprolatone)/siloxane hybrids ,sol–gel ,lithium triflate ,erbium triflate ,erbium β-diketonate complex ,electrochromic devices ,NIR-transparent IMO ,zero-energy buildings ,Technology - Abstract
To address the challenges of the next generation of smart windows for energy-efficient buildings, new electrochromic devices (ECDs) are introduced. These include indium molybdenum oxide (IMO), a conducting oxide transparent in the near-infrared (NIR) region, and a NIR-emitting electrolyte. The novel electrolytes are based on a sol-gel-derived di-urethane cross-linked siloxane-based host structure, including short chains of poly (ε-caprolactone) (PCL(530) (where 530 represents the average molecular weight in g mol−1). This hybrid framework was doped with a combination of either, lithium triflate (LiTrif) and erbium triflate (ErTrif3), or LiTrif and bisaquatris (thenoyltrifluoroacetonate) erbium (III) ([Er(tta)3(H2O)2]). The ECD@LiTrif-[Er(tta)3(H2O)2] device presents a typical Er3+ NIR emission around 1550 nm. The figures of merit of these devices are high cycling stability, good reversibility, and unusually high coloration efficiency (CE = ΔOD/ΔQ, where Q is the inserted/de-inserted charge density). CE values of −8824/+6569 cm2 C−1 and −8243/+5200 cm2 C−1 were achieved at 555 nm on the 400th cycle, for ECD@LiTrif-ErTrif3 and ECD@LiTrif-[Er(tta)3(H2O)2], respectively.
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- 2018
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17. Hybrid nanomaterials: from the laboratory to the market
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Verónica de Zea Bermudez, Fabrice Leroux, Pierre Rabu, and Andreas Taubert
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hybrid nanomaterials ,Technology ,Chemical technology ,TP1-1185 ,Science ,Physics ,QC1-999 - Published
- 2017
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18. Preparation of Well-Dispersed Chitosan/Alginate Hollow Multilayered Microcapsules for Enhanced Cellular Internalization
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Carla Ribeiro, João Borges, Ana M. S. Costa, Vítor M. Gaspar, Verónica de Zea Bermudez, and João F. Mano
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chitosan ,alginate ,marine origin polysaccharides ,biocompatible polymers ,CaCO3 porous microparticles ,layer-by-layer assembly ,hollow multilayered microcapsules ,non-aggregated microcapsules ,cellular internalization ,Organic chemistry ,QD241-441 - Abstract
Hollow multilayered capsules have shown massive potential for being used in the biomedical and biotechnology fields, in applications such as cellular internalization, intracellular trafficking, drug delivery, or tissue engineering. In particular, hollow microcapsules, developed by resorting to porous calcium carbonate sacrificial templates, natural-origin building blocks and the prominent Layer-by-Layer (LbL) technology, have attracted increasing attention owing to their key features. However, these microcapsules revealed a great tendency to aggregate, which represents a major hurdle when aiming for cellular internalization and intracellular therapeutics delivery. Herein, we report the preparation of well-dispersed polysaccharide-based hollow multilayered microcapsules by combining the LbL technique with an optimized purification process. Cationic chitosan (CHT) and anionic alginate (ALG) were chosen as the marine origin polysaccharides due to their biocompatibility and structural similarity to the extracellular matrices of living tissues. Moreover, the inexpensive and highly versatile LbL technology was used to fabricate core-shell microparticles and hollow multilayered microcapsules, with precise control over their composition and physicochemical properties, by repeating the alternate deposition of both materials. The microcapsules’ synthesis procedure was optimized to extensively reduce their natural aggregation tendency, as shown by the morphological analysis monitored by advanced microscopy techniques. The well-dispersed microcapsules showed an enhanced uptake by fibroblasts, opening new perspectives for cellular internalization.
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- 2018
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19. Trimethyl 2,2′,2′′-[1,3,5-triazine-2,4,6-triyltris(azanediyl)]triacetate
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João Rocha, José A. S. Cavaleiro, Verónica de Zea Bermudez, Sérgio M. F. Vilela, Filipe A. Almeida Paz, and João P. C. Tomé
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Crystallography ,QD901-999 - Abstract
The title compound, C12H18N6O6, was synthesized via nucleophilic substitution by reacting 2,4,6-trichloro-1,3,5-triazine with glycine methyl ester hydrochloride in reflux (dried toluene) under anhydrous atmosphere. Individual molecules self-assemble via strong N—H...O hydrogen bonds into supramolecular double tapes running parallel to the [010] crystallographic direction. The close packing of supramolecular tapes is mediated by geometrical reasons in tandem with a number of weaker N—H...O and C—H...N hydrogen-bonding interactions.
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- 2010
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20. Glycine methyl ester hydrochloride
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Sérgio M. F. Vilela, Filipe A. Almeida Paz, João P. C. Tomé, Verónica de Zea Bermudez, José A. S. Cavaleiro, and João Rocha
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Crystallography ,QD901-999 - Abstract
The title compound [systematic name: (methoxycarbonylmethyl)ammonium chloride], crystallizes as a salt, C3H8NO2+·Cl−, with the charged species interacting mutually via strong and highly directional N+—H...Cl− hydrogen bonds which lead to the formation of a supramolecular tape running parallel to the c axis. Tapes close pack in the solid state mediated by multipoint recognition synthons based on weak C—H...O interactions and van der Waals contacts between adjacent methyl groups.
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- 2009
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21. Methyl 2-(4,6-dichloro-1,3,5-triazin-2-ylamino)acetate
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Sérgio M. F. Vilela, Filipe A. Almeida Paz, João P. C. Tomé, Verónica de Zea Bermudez, José A. S. Cavaleiro, and João Rocha
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Crystallography ,QD901-999 - Abstract
The title compound, C6H6Cl2N4O2, was prepared by the nucleophilic substitution of 2,4,6-trichloro-1,3,5-triazine by glycine methyl ester hydrochloride, and was isolated from the reaction by using flash chromatography. The crystal structure at 150 K reveals the presence two crystallographically independent molecules in the asymmetric unit which differ in the orientation of the pendant methoxycarbonyl group. Each molecular unit is engaged in strong and highly directional N—H...N hydrogen-bonding interactions with a symmetry-related molecule, forming supramolecular dimers which act as the synthons in the crystal packing.
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- 2009
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22. Influence of Solvent Evaporation Temperature on the Performance of Ternary Solid Polymer Electrolytes Based on Poly(vinylidene fluoride-co-hexafluoropropylene) Combining an Ionic Liquid and a Zeolite
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João C. Barbosa, Daniela M. Correia, Arkaitz Fidalgo-Marijuan, Renato Gonçalves, Stanislav Ferdov, Verónica de Zea Bermudez, Carlos M. Costa, and Senentxu Lanceros-Mendez
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Materials Chemistry ,Electrochemistry ,Energy Engineering and Power Technology ,Chemical Engineering (miscellaneous) ,Electrical and Electronic Engineering - Published
- 2023
23. Chitosan-based electrolytes containing carbon nanotube-titanium dioxide for energy conversion devices applications
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Naima Naffati, Mariana Fernandes, Verónica de Zea Bermudez, Mohamed Faouzi Nsib, Youssef Arfaoui, Ammar Houas, Joaquim Luis Faria, Cláudia Gomes Silva, and Maria Manuela Silva
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Polymers and Plastics ,General Chemical Engineering ,Materials Chemistry - Published
- 2022
24. Biomimetic Silk Macroporous Materials for Drug Delivery Obtained via Ice-Templating
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Kankan Qin, Rui F. P. Pereira, Thibaud Coradin, Verónica de Zea Bermudez, and Francisco M. Fernandes
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Biomaterials ,Biomimetics ,Ice ,Biochemistry (medical) ,Silk ,Biomedical Engineering ,Animals ,General Chemistry ,Sericins ,Fibroins ,Anti-Bacterial Agents - Abstract
Silk from
- Published
- 2022
25. Influence of ionic liquid characteristics on the performance of ternary solid polymer electrolytes with poly(vinylidene fluoride-co-hexafluoropropylene) and zeolite
- Author
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João Carlos Barbosa, Daniela Maria Correia, Paulo Nunes, Mariana Fernandes, Arkaitz Fidalgo-Marijuan, Renato Gonçalves, Stanislav Ferdov, Verónica de Zea Bermudez, Senentxu Lanceros-Mendez, and Carlos Miguel Costa
- Subjects
Renewable Energy, Sustainability and the Environment ,Energy Engineering and Power Technology ,Electrical and Electronic Engineering ,Physical and Theoretical Chemistry - Published
- 2023
26. Bioinspired In Vitro Brain Vasculature Model for Nanomedicine Testing Based on Decellularized Spinach Leaves
- Author
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Verónica de Zea Bermudez, Vladimir V. Vinogradov, Artur Y Prilepskii, and Aleksandra L Predeina
- Subjects
Brain vasculature ,Decellularization ,biology ,Ethical issues ,Chemistry ,Mechanical Engineering ,Bioengineering ,General Chemistry ,Condensed Matter Physics ,biology.organism_classification ,In vitro ,In vitro model ,Drug development ,Spinach ,Nanomedicine ,General Materials Science ,Biomedical engineering - Abstract
Animal testing is often criticized due to ethical issues and complicated translation of the results obtained to the clinical stage of drug development. Existing alternative models for nanopharmaceutical testing still have many limitations and do not significantly decrease the number of animals used. We propose a simple, bioinspired in vitro model for nanopharmaceutical drug testing based on the decellularized spinach leaf's vasculature. This system is similar to human arterioles and capillaries in terms of diameter (300-10 μm) and branching. The model has proven its suitability to access the maneuverability of magnetic nanoparticles, particularly those composed of Fe3O4. Moreover, the thrombosis has been recreated in the model's vasculature. We have tested and compared the effects of both a single-chain urokinase plasminogen activator (scuPA) and a magnetically controlled nanocomposite prepared by heparin-mediated cross-linking of scuPA with Fe3O4 nanoparticles. Compositions were tested both in static and flow conditions.
- Published
- 2021
27. Gellan‐Gum and LiTFSI‐Based Solid Polymer Electrolytes for Electrochromic Devices
- Author
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Vahideh Bayzi Isfahani, Sónia Pereira, Mariana Fernandes, Ali Arab, Agnieszka Pawlicka, Hamid Rezagholipour Dizaji, Rosa Rego, R. C. Sabadini, Rui F. P. Pereira, Maria Manuela Silva, Elvira Fortunato, and Verónica de Zea Bermudez
- Subjects
ELETRÓLITOS ,Prussian blue ,Materials science ,Polymer electrolytes ,02 engineering and technology ,General Chemistry ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochromic devices ,01 natural sciences ,Gellan gum ,0104 chemical sciences ,chemistry.chemical_compound ,Chemical engineering ,chemistry ,0210 nano-technology - Published
- 2021
28. Vicariance Between
- Author
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Rui F P, Pereira, João, Rocha, Paulo, Nunes, Tânia, Fernandes, Ajith P, Ravishankar, Rebeca, Cruz, Mariana, Fernandes, Srinivasan, Anand, Susana, Casal, Verónica, de Zea Bermudez, and António L, Crespí
- Abstract
Classically, vicariant phenomena have been essentially identified on the basis of biogeographical and ecological data. Here, we report unequivocal evidences that demonstrate that a physical-chemical characterization of the epicuticular waxes of the surface of plant leaves represents a very powerful strategy to get rich insight into vicariant events. We found vicariant similarity between
- Published
- 2022
29. High-Performance room temperature Lithium-Ion battery solid polymer electrolytes based on Poly(vinylidene fluoride- co-hexafluoropropylene) combining ionic liquid and Zeolite
- Author
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Verónica de Zea Bermudez, Senentxu Lanceros-Méndez, Stanislav Ferdov, Carlos M. Costa, Daniela M. Correia, J.C. Barbosa, Gotzone Barandika, Eva M. Fernández, Arkaitz Fidalgo-Marijuan, Renato Ferreira Gonçalves, and Universidade do Minho
- Subjects
Battery (electricity) ,Lithium-ion batteries ,Materials science ,Ciências Naturais::Ciências Físicas ,Ciências Físicas [Ciências Naturais] ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Lithium-ion battery ,chemistry.chemical_compound ,Ionic conductivity ,General Materials Science ,Thermal stability ,Água potável e saneamento ,Composites ,Room temperature ,chemistry.chemical_classification ,Science & Technology ,Polymer ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,chemistry ,Chemical engineering ,Ionic liquid ,PVDF-HFP ,Solid polymer electrolytes ,Hexafluoropropylene ,0210 nano-technology - Abstract
The demand for more efficient energy storage devices has led to the exponential growth of lithium-ion batteries. To overcome the limitations of these systems in terms of safety and to reduce environmental impact, solid-state technology emerges as a suitable approach. This work reports on a three-component solid polymer electrolyte system based on poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP), the ionic liquid 1-butyl-3-methylimidazolium thiocyanate ([BMIM][SCN]), and clinoptilolite zeolite (CPT). The influences of the preparation method and of the dopants on the electrolyte stability, ionic conductivity, and battery performance were studied. The developed electrolytes show an improved room temperature ionic conductivity (1.9 × 10–4 S cm–1), thermal stability (up to 300 °C), and mechanical stability. The corresponding batteries exhibit an outstanding room temperature performance of 160.3 mAh g–1 at a C/15-rate, with a capacity retention of 76% after 50 cycles. These results represent a step forward in a promising technology aiming the widespread implementation of solid-state batteries., FCT (Fundação para a Ciência e Tecnologia) for financial support under the framework of Strategic Funding grants UID/CTM/50025/2021, UID/FIS/04650/2021, UID/EEA/04436/2021 and UID/QUI/0686/2021; and support from FEDER funds through the COMPETE 2020 Programme (projects PTDC/FISMAC/28157/2017 and POCI-01-0145-FEDER-007688). Grants SFRH/BD/140842/2018 (J.C.B.) and SFRH/BPD/121526/2016 (D.M.C) and contracts under the Stimulus of Scientific Employment, Individual Support CEECIND/00833/2017 (R.G.) and 2020.04028 CEECIND (C.M.C.) are acknowledged. Financial support from the Basque Government under the ELKARTEK program, Basque University System Research Groups, IT-1290-19 and the University of the Basque Country (GIU18/197). is also acknowledged
- Published
- 2022
30. Eco-friendly superabsorbent hydrogels based on starch, gellan gum, citric acid, and nanoclays for soil humidity control
- Author
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Rodrigo C. Sabadini, Mariana Fernandes, Verónica de Zea Bermudez, Agnieszka Pawlicka, and Maria M. Silva
- Subjects
Polymers and Plastics ,GOMAS E RESINAS ,Materials Chemistry ,General Chemistry ,Surfaces, Coatings and Films - Published
- 2022
31. High-Performance Room Temperature Lithium-Ion Battery Solid Polymer Electrolytes Based on Poly(vinylidene fluoride
- Author
-
João C, Barbosa, Daniela M, Correia, Eva M, Fernández, Arkaitz, Fidalgo-Marijuan, Gotzone, Barandika, Renato, Gonçalves, Stanislav, Ferdov, Verónica, de Zea Bermudez, Carlos M, Costa, and Senentxu, Lanceros-Mendez
- Abstract
The demand for more efficient energy storage devices has led to the exponential growth of lithium-ion batteries. To overcome the limitations of these systems in terms of safety and to reduce environmental impact, solid-state technology emerges as a suitable approach. This work reports on a three-component solid polymer electrolyte system based on poly(vinylidene fluoride
- Published
- 2021
32. Three‐Component Solid Polymer Electrolytes Based on Li‐Ion Exchanged Microporous Silicates and an Ionic Liquid for Solid‐State Batteries
- Author
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João C. Barbosa, Daniela M. Correia, Manuel Salado, Renato Gonçalves, Stanislav Ferdov, Verónica de Zea Bermudez, Carlos M. Costa, and Senentxu Lanceros-Mendez
- Subjects
General Materials Science ,Condensed Matter Physics - Published
- 2022
33. Sustainable Dual-Mode Smart Windows for Energy-Efficient Buildings
- Author
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Sónia Pereira, Rosa Rego, Rute A. S. Ferreira, Sofia Saraiva, Luís D. Carlos, Rui F. P. Pereira, S. C. Nunes, Maria Manuela Silva, Elvira Fortunato, Verónica de Zea Bermudez, and Universidade do Minho
- Subjects
Ciências Químicas [Ciências Naturais] ,erbium triflate ,Computer science ,Energy Engineering and Power Technology ,Library science ,Sample (statistics) ,02 engineering and technology ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,energy-efficient glazing for buildings ,κ-carrageenan polysaccharide ,Materials Chemistry ,Electrochemistry ,Chemical Engineering (miscellaneous) ,Electrical and Electronic Engineering ,Science & Technology ,Dual mode ,window daylighting control ,021001 nanoscience & nanotechnology ,Ciências Naturais::Ciências Químicas ,0104 chemical sciences ,heating saving ,kappa-carrageenan polysaccharide ,NIR-emitting smart windows ,13. Climate action ,glare reduction ,0210 nano-technology ,Efficient energy use - Abstract
Electrochromic devices (ECDs) combining visible/near-infrared (NIR) transparent amorphous indium zinc oxide (a-IZO) external layers with innovative NIR-emitting electrolytes composed of red seaweed-derived kappa-carrageenan (kappa-Cg) polysaccharide, glycerol (Gly), and erbium triflate (ErTrif(3)center dot xH(2)O) are proposed as a valuable technological solution for the development of smart windows providing less heating demand, less glare and more indoors human comfort for the new generation of energy-efficient buildings. The electrolyte preparation is cheap, clean, and fast. The optimized sample including 50 wt% Gly/kappa-Cg and 40 wt% ErTrif(3)center dot xH(2)O/kappa-Cg exhibits the highest ionic conductivity (1.5 X 10(-4) S cm(-1) at 20 degrees C) and displays ultraviolet (UV)/blue and NIR emissions associated with the kappa-Cg-based host and the Er3+ ions (I-4(15/2) -> I-4(13/2)), respectively. The 5-layer configuration ECD tested demonstrated fast switching time (50 s), high electrochromic contrast (transmittance variations of 46/51% at 550/1000 nm), high optical density change (0.89/0.75 at 550/1000 nm), outstanding coloration efficiency (450th cycle = -15902/-13400 cm(2) C-1 and +3072/+2589 cm(2) C-1 at 550/1000 nm for coloration and bleaching, respectively), excellent electrochemical stability, and self-healing after mechanical damage. The ECD encompasses two voltage-operated modes: semibright warm (+3.0 V, transmittances of 52/61% at 550/1000 nm) and dark cold (-3.0 V, transmittances of 7/11% at 550/1000 nm)., This work was supported by FEDER, through COMPETE and Fundacao para a Ciencia e a Tecnologia (FCT) (FCOMP-01-0124-FEDER-037271, Pest-OE/QUI/UI0616/2014, and UID/CTM/50025/2019), project LUMECD (POCI-01-0145-FEDER-016884 and PTDC/CTM-NAN/0956/2014), project UniRCell (ref. SAICTPAC/0032/2015, POCI-01-0145-FEDER-016422), and by the Portuguese National NMR Network (RNRMN). S.C.N. acknowledges FCT for grants (Post -PhD Fellowships of UniRCell and LUMECD projects). R.F.P.P. acknowledges FCT for SFRH/BPD/87759/2012 grant. The authors thank CPKelco (U.S.A.) for providing the x-carrageenan sample.
- Published
- 2019
34. Hydrogen, Fuel Cells and Advanced Batteries (HYCEL 2017): Foreword
- Author
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Verónica de Zea Bermudez
- Subjects
Materials science ,Waste management ,General Chemical Engineering ,Hydrogen fuel ,Electrochemistry - Published
- 2018
35. Solar spectral management with electrochromic devices including PMMA films doped with biluminescent ionosilicas
- Author
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Sónia Pereira, Teresa M. R. Maria, Artur J.M. Valente, Maria Manuela Silva, Helena Gonçalves, M. A. Cardoso, Verónica de Zea Bermudez, Elvira Fortunato, Rute A. S. Ferreira, Rui F. P. Pereira, and Sandra F. H. Correia
- Subjects
Materials science ,business.industry ,Doping ,Luminescent solar concentrator ,General Chemistry ,Condensed Matter Physics ,Electrochromic devices ,Electronic, Optical and Magnetic Materials ,Amorphous solid ,Biomaterials ,chemistry.chemical_compound ,chemistry ,Ionic liquid ,Materials Chemistry ,Ceramics and Composites ,Transmittance ,Optoelectronics ,Ionic conductivity ,Luminescence ,business - Abstract
The technological potential of poly(methyl methacrylate) (PMMA)-based composite films doped with lanthanide-doped sol–gel derived ionosilicas (IS-Ln) previously proposed for luminescent down-shifting (LDS) and luminescent solar concentrator (LSC) layers connected to photovoltaic (PV) cells is extended here to electrochromic devices (ECDs), targeting the fabrication of single energy harvesting/conversion/management LSC-LDS/PV/ECD systems. These integrated devices have foreseen application in the windows of future zero-energy buildings of smart cities. The proof-of-concept is given with the report of the electro-optical performance of an ECD comprising an optimized electrolyte film composed of PMMA, IS-Nd, and IS-Eu, and the 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid. This amorphous electrolyte is stable below 160 °C, exhibits high ionic conductivity (2.13 × 10−4 and 8.76 × 10−4 S cm−1 at room temperature and 44 °C, respectively), and emits in the visible (red color) and near-infrared (NIR) spectral regions. The device demonstrated fast switching speed (50 s) and high transparency in the visible-to-NIR spectral regions (transmittance (T) = 79/96/89/77% at 555/1000/1500/1650 nm in the as-prepared state, respectively). Upon application of ±2.5 V for 200 cycles, at the same wavelengths, the Tbleached/Tcolored values were 44/28, 46/26, 39/20, and 27/9%, respectively, and the coloration efficiency (CE) values CEin/CEout values were −302/+181, −381/+228, −446/+267 and −734/+440 cm2 C−1, respectively. published
- Published
- 2021
36. Redesigned Silk: A New Macroporous Biomaterial Platform for Antimicrobial Dermal Patches with Unique Exudate Wicking Ability
- Author
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Thibaud Coradin, Verónica de Zea Bermudez, Francisco M. Fernandes, Rui F. P. Pereira, and Kankan Qin
- Subjects
Materials science ,Biocompatibility ,biology ,Biomaterial ,Fibroin ,Nanotechnology ,engineering.material ,biology.organism_classification ,Sericin ,SILK ,Coating ,Bombyx mori ,Drug delivery ,engineering - Abstract
Silk is one of the most important materials in the history of medical practice. Owing to its excellent strength, biocompatibility and degradability, silk from Bombyx mori – which is structured as a concentric assembly of silk fibroin (SF) coated by a sheath of sericin (SS) – has long been used for wound treatment. Here, we recapitulate for the first time the topology of native silk fibers using a radically new materials design-oriented approach to achieve unprecedented porous dermal patches suitable for controlled drug delivery. The method implies four steps: (1) removing SS; (2) creating anisotropic macroporosity in SF via ice templating; (3) stabilizing the SF foam with a methanolic solution of Rifamycin (Rif) antibiotic; and (4) coating Rif-loaded redesigned SF foams with a SS sheath. The core-shell SS@SF foams exhibit water wicking properties accommodate up to ~20% lateral deformation. Moreover, monitoring of antibacterial activity against Staphylococcus aureus revealed that the SS@SF foams’ Rif release extended up to 9 days. We anticipate that reverse-engineering of silk foams opens exciting new avenues towards the fabrication of advanced drug eluting silk-based biomaterial platforms with improved performance. The present approach can be generalizable to re-build multicomponent biological materials with tunable porosity.
- Published
- 2020
37. Proton conducting electrolytes composed of chondroitin sulfate polysaccharide and citric acid
- Author
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Rui F. P. Pereira, Artur J.M. Valente, Verónica de Zea Bermudez, Paula Barbosa, Maria Manuela Silva, S. C. Nunes, Helena Gonçalves, Filipe M. Santos, Filipe M.L. Figueiredo, Repositório Científico do Instituto Politécnico do Porto, and Universidade do Minho
- Subjects
Ciências Químicas [Ciências Naturais] ,Chondroitin sulfate ,Polymers and Plastics ,General Physics and Astronomy ,02 engineering and technology ,Electrolyte ,010402 general chemistry ,Polysaccharide ,7. Clean energy ,01 natural sciences ,law.invention ,chemistry.chemical_compound ,Citric acid ,Magazine ,Ionic conductivity ,law ,Materials Chemistry ,Biopolymer electrolytesIonic conductivity ,chemistry.chemical_classification ,Science & Technology ,Organic Chemistry ,021001 nanoscience & nanotechnology ,Ciências Naturais::Ciências Químicas ,Biopolymer electrolytes ,0104 chemical sciences ,Amorphous solid ,chemistry ,Crystallite ,0210 nano-technology ,Nuclear chemistry - Abstract
Novel electrolytes composed of chondroitin sulfate A (CSA) and citric acid (CA) have been prepared using a clean, safe, and fast route. These electrolytes exhibit different physical-chemical properties, depending on the amount of CA. For X > 82.3%, where X is the mass ratio, in %, of CA/(CA + CSA), whitish polycrystalline powders result. Lower amounts of CA leads to the production of translucent, amorphous films, sticky for X = 75.6 and 82.0, brittle for X < 43.6 and crack-free, self-standing for 43.6 < X < 75.6%. The results obtained provide evidence that, at low pH, strong hydrogen bonding interactions take place between the anionic sulfonic and carboxylic groups of CSA and CA. CA exerts a key role, acting as a cross-linker and proton source, while simultaneously influencing sample morphology. At room temperature the highest ionic conductivity is achieved at X = 60.8%. A significant enhancement of the ionic conductivity of this sample occurs with the increase of relative humidity (RH) (from 3.1 × 10−7 to 3.7 × 10−2 S cm−1 30% for RH = 30 and ~100%, respectively)., Support by Fundação para a Ciência e Tecnologia, I.P. (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013, UID/QUI/ 00686/2013, UID/QUI/50006/2019 and UID/QUI/00686/2016. This work was funded by the R&D Project UniRCell-Unitised regenerative fuel cell for efficient renewable energy supply: from materials to device, with reference POCI-01-0145-FEDER-016422 and SAICTPAC/0032/ 2015, financed by the European Regional Development Fund (ERDF) through COMPETE 2020 – Operational Program for Competitiveness and Internationalization (POCI) and by the Foundation for Science and Technology (FCT) and CICECO-Aveiro Institute of Materials (UID/ CTM/50011/2019), financed by national funds through the FCT/MEC. Is also acknowledged, as well as funding under projects UID/CTM/ 50025/2013, Pest-OE/QUI/UI0616/2014, and LUMECD (PTDC/CTM/ NAN/0956/20149 and POCI-01-0145-FEDER-016884). F. M. Santos acknowledges a Post-PhD Fellow grant supported by Project UniRcell. P. C. Barbosa employment contract is funded by national funds (OE), through FCT – Fundação para a Ciência e a Tecnologia, I.P., in the scope of the framework contract foreseen in the numbers 4, 5 and 6 of the article 23, of the Decree-Law 57/2016, of August 29, changed by Law 57/2017, of July 19.R. F. P. Pereira Post-PhD fellow was funded by FCT (SFRH/BPD/87759/2012). S. C. Nunes was funded by FCT projects (Post-PhD Fellowships of UniRCell and LUMECD projects). H.M.R. Gonçalves was funded by NORTE-01-0145-FEDER-030858 and PTDC/ BTM-MAT/30858/2017.
- Published
- 2020
38. Highly Conducting Bombyx mori Silk Fibroin-Based Electrolytes Incorporating Glycerol, Dimethyl Sulfoxide and [Bmim]PF6
- Author
-
Artur J.M. Valente, Rui F. P. Pereira, Joana F. M. Sousa, Tania C. D. Fernandes, Filipe A. Almeida Paz, Maria Manuela Silva, Helena M. R. Rodrigues, Verónica de Zea Bermudez, Repositório Científico do Instituto Politécnico do Porto, and Universidade do Minho
- Subjects
Ciências Químicas [Ciências Naturais] ,Science & Technology ,Renewable Energy, Sustainability and the Environment ,020209 energy ,02 engineering and technology ,Condensed Matter Physics ,Ciências Naturais::Ciências Químicas ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,[Bmim]PF6 ,Political science ,0202 electrical engineering, electronic engineering, information engineering ,Materials Chemistry ,Electrochemistry ,Humanities ,Bombyx mori silk fibroin (SF) - Abstract
Green, transparent and flexible electrolyte films composed of a Bombyx mori silk fibroin (SF) host biopolymer doped with glycerol (G), dimethyl sulfoxide (DMSO, D) and 1-butyl-3-methylimidazolium hexafluorophosphate ([Bmim]PF6) ionic liquid (IL), were synthesized. The materials were represented by the notation SF@GD@ILx (x = 15, 20 and 30 is the mass ratio of SF/[Bmim]PF6 in %). SF@, SF@G, SF@D and SF@GD samples were also prepared. DMSO was found to play a dual-role, acting as solvent of [Bmim]PF6, and enhancing ionic conductivity. DMSO, alone or combined with [Bmim]PF6, led to the increase of the mean roughness and induced the formation of more ordered Silk II conformations (beta-sheets). No structural modifications were detected in the SF@GD@ILx samples upon increasing the temperature up to 100 degrees C. The highest ionic conductivity was exhibited by the IL-rich sample SF@GD@IL30 (1.07 and 4.61 mS cm(-1), at 22 and 100 degrees C, respectively). In the [Bmim]PF6-doped electrolytes "free" and coordinated PF6- ions coexist. The weight losses occurring below 200 degrees C involved essentially the release of adsorbed water and DMSO. The suitable mechanical properties, high ionic conductivity and good electrochemical stability suggest that these electrolytes are attractive candidates for application in electrochemical devices., Veronica de Zea Bermudez would like to express her gratitude to Professor Michel Armand who, during her PhD thesis at Grenoble (1989-1992), was an endless source of ideas that made her work productive and stimulating. His qualities, as an inspiring and extraordinary scientist, equal his kindness, generosity and great heart. This work was supported by National funds by Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/QUI/00686/2018, UID/QUI/00686/2019, UID/QUI/50006/2019 and UID/QUI/00313/2020. The authors thank FEDER funds through the COMPETE 2020 Program and National Funds through FCT under the projects PEst-OE/QUI/UI0616/2014, LUMECD (POCI-01-0145-FEDER-016884 and PTDC/CTMNAN/0956/2014), UniRCell (POCI-01-0145-FEDER-016422 and SAICTPAC/0032/2015), PORPLANTSURF (POCI-01-0145FEDER-029785 and PTDC/CTM-REF/29785/2017), and NORTE01-0145-FEDER-030858. R.F.P.P thanks FCT-UM for the researcher contract in the scope of Decreto-Lei 57/2016 and 57/2017. H.M.R. Goncalves was funded by PTDC/BTM-MAT/30858/2017.
- Published
- 2020
39. Ionic Liquid-Assisted Synthesis of Mesoporous Silk Fibroin/Silica Hybrids for Biomedical Applications
- Author
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S. C. Nunes, Andreas Taubert, Tiago dos Santos, Verónica de Zea Bermudez, Filipe A. Almeida Paz, Pedro L. Granja, Maria Manuela Silva, Rui F. P. Pereira, Kerstin Zehbe, Christina Günter, Instituto de Investigação e Inovação em Saúde, and Universidade do Minho
- Subjects
Ciências Químicas [Ciências Naturais] ,Materials science ,General Chemical Engineering ,Fibroin ,02 engineering and technology ,010402 general chemistry ,01 natural sciences ,Chloride ,Article ,Catalysis ,lcsh:Chemistry ,chemistry.chemical_compound ,medicine ,Science & Technology ,Resazurin ,General Chemistry ,021001 nanoscience & nanotechnology ,Ciências Naturais::Ciências Químicas ,0104 chemical sciences ,Amorphous solid ,Solvent ,lcsh:QD1-999 ,chemistry ,Chemical engineering ,Ionic liquid ,ddc:540 ,Institut für Chemie ,0210 nano-technology ,Mesoporous material ,medicine.drug - Abstract
New mesoporous silk fibroin (SF)/silica hybrids were processed via a one-pot soft and energy-efficient sol-gel chemistry and self-assembly from a silica precursor, an acidic or basic catalyst, and the ionic liquid 1-butyl-3-methylimidazolium chloride, acting as both solvent and mesoporosity-inducer. The as-prepared materials were obtained as slightly transparent-opaque, amorphous monoliths, easily transformed into powders, and stable up to ca. 300 degrees C. Structural data suggest the formation of a hexagonal mesostructure with low range order and apparent surface areas, pore volumes, and pore radii of 205-263 m(2) g(-1), 0.16-0.19 cm(3) g(-1), and 1.2-1.6 nm, respectively. In all samples, the dominating conformation of the SF chains is the beta-sheet. Cytotoxicity/bioactivity resazurin assays and fluorescence microscopy demonstrate the high viability of MC3T3 pre-osteoblasts to indirect (>= 99 +/- 9%) and direct (78 +/- 2 to 99 +/- 13%) contact with the SF/silica materials. Considering their properties and further improvements, these systems are promising candidates to be explored in bone tissue engineering. They also offer excellent prospects as electrolytes for solid-state electrochemical devices, in particular for fuel cells., This work was supported by Fundacao para a Ciencia e a Tecnologia (FCT)/Deutscher Akademischer Austauschdienst (DAAD) Transnational Cooperation Project no. 6818 "Ionic liquid-and ionic liquid crystal-assisted formation of hybrid biomaterials scaffolds". We further wish to thank the European Union, QREN, FEDER through "Programa Operacional Factores de Competitividade" (COMPETE), and CICECO-Aveiro Institute of Materials, POCI-01-0145-FEDER-007679 (FCT Ref. UID/CTM/50011/2013), financed by national funds through the FCT/MEC and when appropriate co-financed by FEDER under the PT2020 Partnership Agreement. This work was also funded by project UniRCell (POCI-01-0145-FEDER-016422 and SAICTPAC/0032/2015) financed by the European Regional Development Fund (ERDF) through COMPETE 2020, POCI and FCT. We also thank FCT in the framework of Strategic Funding UID/QUI/00686/2013 and UID/QUI/00686/2016, and funding under project PEst-OE/QUI/UI0616/2014. R.F.P.P. acknowledges FCT for a grant (SFRH/BPD/87759/2012).
- Published
- 2018
40. Insight on polymer electrolytes for electrochemical devices applications
- Author
-
Agnieszka Pawlicka, Maria Manuela Silva, Verónica de Zea Bermudez, and Universidade do Minho
- Subjects
Materials science ,Solid polymer ectrolytes ,Polymer electrolytes ,Nanotechnology ,Solid-state electrochemistry ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,7. Clean energy ,01 natural sciences ,Ciências Naturais::Ciências Químicas ,0104 chemical sciences ,Electrochemical devices ,0210 nano-technology - Abstract
Polymer electrolytes (PEs) are of much attention as potential electrolytes of great technological relevance for solid-state electrochemistry, in particular for their possible practical application in devices such as batteries, supercapacitors, fuel cells, smart windows, sensors, and solar cells, among others. Generically, solid polymer electrolytes (SPEs) are mixtures of salts with basic polymers, such as poly(ethylene oxide) (PEO) or poly(ethylene imine) (PEI). However, there are also other polymers used as matrices for ionic conduction, like poly(vinyl alcohol) (PVA), poly(vinylidene fluoride) (PVDF), or natural macromolecules. A brief description of theoretical aspects of different PEs and past and recent trends in development of these materials are presented in this chapter. SPEs have many advantages including high energy density, no risk of leakage, no deleterious issues related to the presence of solvent, wide electrochemical stability window, simplified processability, and light weight. Some examples of prototypes of electrochromic device (ECD), batteries, supercapacitors, fuel cells, sensors, dye sensitized solar cells (DSSCs), and light emitting electrochemical cells are also presented and discussed in scope of this contribution., (undefined)
- Published
- 2019
41. Bombyx mori silk/titania/gold hybrid materials for photocatalytic water splitting: combining renewable raw materials with clean fuels
- Author
-
Andreas Taubert, Christian Kübel, Verónica de Zea Bermudez, Rafael Meinusch, Stefanie Krüger, Dorothée Vinga Szabó, Christina Günter, Michael Bruns, Michael Schwarze, and Otto Baumann
- Subjects
Anatase ,Technology ,Materials science ,General Physics and Astronomy ,02 engineering and technology ,lcsh:Chemical technology ,010402 general chemistry ,lcsh:Technology ,01 natural sciences ,Full Research Paper ,Nanotechnology ,lcsh:TP1-1185 ,General Materials Science ,titania ,Electrical and Electronic Engineering ,lcsh:Science ,Porosity ,photocatalytic water splitting ,lcsh:T ,Brookite ,gold ,021001 nanoscience & nanotechnology ,lcsh:QC1-999 ,0104 chemical sciences ,Bombyx mori silk ,Nanoscience ,SILK ,Chemical engineering ,visual_art ,Photocatalysis ,visual_art.visual_art_medium ,Water splitting ,lcsh:Q ,0210 nano-technology ,Hybrid material ,ddc:600 ,lcsh:Physics ,Photocatalytic water splitting - Abstract
The synthesis, structure, and photocatalytic water splitting performance of two new titania (TiO 2 )/gold(Au)/Bombyx mori silk hybrid materials are reported. All materials are monoliths with diameters of up to ca. 4.5 cm. The materials are macroscopically homogeneous and porous with surface areas between 170 and 210 m 2/g. The diameter of the TiO 2 nanoparticles (NPs) – mainly anatase with a minor fraction of brookite – and the Au NPs are on the order of 5 and 7–18 nm, respectively. Addition of poly(ethylene oxide) to the reaction mixture enables pore size tuning, thus providing access to different materials with different photocatalytic activities. Water splitting experiments using a sunlight simulator and a Xe lamp show that the new hybrid materials are effective water splitting catalysts and produce up to 30 mmol of hydrogen per 24 h. Overall the article demonstrates that the combination of a renewable and robust scaffold such as B. mori silk with a photoactive material provides a promising approach to new monolithic photocatalysts that can easily be recycled and show great potential for application in lightweight devices for green fuel production., Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe, 581
- Published
- 2018
42. Sustainable Lithium‐Ion Battery Separators Based on Poly(3‐Hydroxybutyrate‐Co‐Hydroxyvalerate) Pristine and Composite Electrospun Membranes
- Author
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Arkaitz Fidalgo-Marijuan, J.C. Barbosa, Maria Manuela Silva, Senentxu Lanceros-Méndez, Mariana Fernandes, Carlos M. Costa, Verónica de Zea Bermudez, Renato Ferreira Gonçalves, and Daniela M. Correia
- Subjects
General Energy ,Materials science ,Chemical engineering ,Composite number ,Poly-3-hydroxybutyrate ,02 engineering and technology ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,Electrospun membranes ,01 natural sciences ,Lithium-ion battery ,0104 chemical sciences - Published
- 2021
43. Luminescent Poly(vinylidene fluoride)‐Based Inks for Anticounterfeiting Applications
- Author
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Verónica de Zea Bermudez, Daniela M. Correia, Carmen R. Tubío, Rute A. S. Ferreira, Gabriela Botelho, Nelson A. M. Pereira, M. A. Cardoso, Senentxu Lanceros-Méndez, and Rita Polícia
- Subjects
chemistry.chemical_compound ,Materials science ,chemistry ,Nanotechnology ,02 engineering and technology ,General Medicine ,010402 general chemistry ,021001 nanoscience & nanotechnology ,0210 nano-technology ,Luminescence ,01 natural sciences ,Fluoride ,0104 chemical sciences - Published
- 2021
44. Improved response of ionic liquid-based bending actuators by tailored interaction with the polar fluorinated polymer matrix
- Author
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Clarisse Ribeiro, José Luis Vilas, J. C. Dias, Carlos M. Costa, Gabriela Botelho, Daniela M. Correia, Senentxu Lanceros-Méndez, Alberto Maceiras, Verónica de Zea Bermudez, and Universidade do Minho
- Subjects
Materials science ,General Chemical Engineering ,02 engineering and technology ,Bending ,Ionic liquid ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,Matrix (mathematics) ,Electrochemistry ,Imide ,chemistry.chemical_classification ,Science & Technology ,Copolymers ,PVDF ,Polymer ,021001 nanoscience & nanotechnology ,Bending actuation ,0104 chemical sciences ,chemistry ,Chemical engineering ,Polar ,0210 nano-technology ,Actuator ,Fluoride ,Actuators - Abstract
Poly(vinylidene fluoride) (PVDF), poly(vinylidene fluoride-co-trifluoroethylene) (PVDF-TrFE), poly(vinylidene fluoride-co-hexafluropropylene) (PVDF-HFP) and poly(vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) were evaluated for the development of ionic liquid (IL) - polymer composite bending actuators. The selected guest IL, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, [Emim][TFSI], was incorporated into the different host polymer matrixes in concentrations ranging from 10 to 40wt%. The IL/polymer composites electrical properties strongly depend on the IL content. The largest bending response was found for the IL/PVDF-TrFE composites with a maximum bending value of 3.5mm using a frequency of 100mHzat an applied potential difference of 5.0 Vpp. Thus, PVDF-TrFE are attractive candidates for the development of high performance bending actuators., Work supported by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UID/FIS/04650/2013, UID/QUI/00686/2013 and UID/QUI/0686/2016. The authors thank FEDER funds through the COMPETE 2020 Programme and National Funds through FCT under the projects PTDC/CTM-ENE/5387/2014 and UID/CTM/50025/2013 and Grants SFRH/BD/90215/2012 (J.C.D.), SFRH/BPD/121526/2016 (D.M.C), SFRH/BPD/112547/2015 (C.M.C.), SFRH/BPD/90870/2012 (C.R.). Financial support from the Spanish Ministry of Economy and Competitiveness (MINECO) through the project MAT2016-76039-C4-3-R (AEI/FEDER, UE) (including the FEDER financial support) and from the Basque Government Industry Department under the ELKARTEK and HAZITEK program and Grupos de Investigación, IT718-13, is also acknowledged., info:eu-repo/semantics/publishedVersion
- Published
- 2019
45. Transparent luminescent solar concentrators using Ln3+-based ionosilicas towards photovoltaic windows
- Author
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Verónica de Zea Bermudez, Luís D. Carlos, Sandra F. H. Correia, Paulo André, Ana R. Frias, M. A. Cardoso, Ana R. N. Bastos, and Rute A. S. Ferreira
- Subjects
Lanthanide ,Brightness ,Control and Optimization ,Materials science ,Poly(methyl methacrylate) ,Energy Engineering and Power Technology ,02 engineering and technology ,010402 general chemistry ,lcsh:Technology ,01 natural sciences ,ionosilicas ,Photovoltaics ,Luminescent solar concentrators ,Lanthanides ,lanthanides ,Electrical and Electronic Engineering ,Engineering (miscellaneous) ,Ionosilicas ,lcsh:T ,Renewable Energy, Sustainability and the Environment ,business.industry ,Photovoltaic system ,Energy conversion efficiency ,Molar absorptivity ,poly(methyl methacrylate) ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,photovoltaics ,visual_art ,visual_art.visual_art_medium ,Optoelectronics ,0210 nano-technology ,business ,Luminescence ,Energy (miscellaneous) - Abstract
The integration of photovoltaic (PV) elements in urban environments is gaining visibility due to the current interest in developing energetically self-sustainable buildings. Luminescent solar concentrators (LSCs) may be seen as a solution to convert urban elements, such as faç, ades and windows, into energy-generation units for zero-energy buildings. Moreover, LSCs are able to reduce the mismatch between the AM1.5G spectrum and the PV cells absorption. In this work, we report optically active coatings for LSCs based on lanthanide ions (Ln3+ = Eu3+, Tb3+)-doped surface functionalized ionosilicas (ISs) embedded in poly(methyl methacrylate) (PMMA). These new visible-emitting films exhibit large Stokes-shift, enabling the production of transparent coatings with negligible self-absorption and large molar extinction coefficient and brightness values (~2 ×, 105 and ~104 M&minus, 1∙cm&minus, 1, respectively) analogous to that of orange/red-emitting organic dyes. LSCs showed great potential for efficient and environmentally resistant devices, with optical conversion efficiency values of ~0.27% and ~0.34%, respectively.
- Published
- 2019
46. Luminescent electrochromic devices for smart windows of energy-efficient buildings
- Author
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Luís D. Carlos, Vânia T. Freitas, Rosa Rego, Rute A. S. Ferreira, Maria Manuela Silva, Sónia Pereira, Verónica de Zea Bermudez, R. Leones, Mariana Fernandes, Elvira Fortunato, UNINOVA-Instituto de Desenvolvimento de Novas Tecnologias, CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N), DCM - Departamento de Ciência dos Materiais, and Universidade do Minho
- Subjects
Engineering ,erbium -diketonate complex ,erbium triflate ,Control and Optimization ,Lithium triflate ,Energy Engineering and Power Technology ,02 engineering and technology ,Sol–gel ,010402 general chemistry ,Electrochromic devices ,7. Clean energy ,01 natural sciences ,lcsh:Technology ,Erbium triflate ,zero-energy buildings ,sol-gel ,SDG 7 - Affordable and Clean Energy ,electrochromic devices ,Zero-energy buildings ,Electrical and Electronic Engineering ,Engineering (miscellaneous) ,poly(epsilon-caprolatone) ,Zero-energy building ,Science & Technology ,siloxane hybrids ,lithium triflate ,business.industry ,lcsh:T ,Renewable Energy, Sustainability and the Environment ,021001 nanoscience & nanotechnology ,Engineering physics ,0104 chemical sciences ,sol–gel ,Poly(ε-caprolatone)/siloxane hybrids ,NIR-transparent IMO ,erbium β-diketonate complex ,poly(ε-caprolatone)/siloxane hybrids ,0210 nano-technology ,business ,Erbium β-diketonate complex ,Efficient energy use ,Energy (miscellaneous) - Abstract
To address the challenges of the next generation of smart windows for energy-efficient buildings, new electrochromic devices (ECDs) are introduced. These include indium molybdenum oxide (IMO), a conducting oxide transparent in the near-infrared (NIR) region, and a NIR-emitting electrolyte. The novel electrolytes are based on a sol-gel-derived di-urethane cross-linked siloxane-based host structure, including short chains of poly (&epsilon, caprolactone) (PCL(530) (where 530 represents the average molecular weight in g mol&minus, 1). This hybrid framework was doped with a combination of either, lithium triflate (LiTrif) and erbium triflate (ErTrif3), or LiTrif and bisaquatris (thenoyltrifluoroacetonate) erbium (III) ([Er(tta)3(H2O)2]). The ECD@LiTrif-[Er(tta)3(H2O)2] device presents a typical Er3+ NIR emission around 1550 nm. The figures of merit of these devices are high cycling stability, good reversibility, and unusually high coloration efficiency (CE = &Delta, OD/&Delta, Q, where Q is the inserted/de-inserted charge density). CE values of &minus, 8824/+6569 cm2 C&minus, 1 and &minus, 8243/+5200 cm2 C&minus, 1 were achieved at 555 nm on the 400th cycle, for ECD@LiTrif-ErTrif3 and ECD@LiTrif-[Er(tta)3(H2O)2], respectively.
- Published
- 2018
47. Smart Windows Prepared from Bombyx mori Silk
- Author
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F. Sentanin, Maria Manuela Silva, Rui F. P. Pereira, M. Cristina Gonçalves, Verónica de Zea Bermudez, Agnieszka Pawlicka, and Universidade do Minho
- Subjects
Ciências Químicas [Ciências Naturais] ,Materials science ,POLÍMEROS (MATERIAIS) ,Lithium tetrafluoroborate ,Fibroin ,chemistry.chemical_element ,02 engineering and technology ,010402 general chemistry ,Electrochromic devices ,01 natural sciences ,Catalysis ,chemistry.chemical_compound ,polymer electrolytes ,Polymer chemistry ,Electrochemistry ,Ionic conductivity ,sustainable chemistry ,electrochromic devices ,Thin film ,Science & Technology ,Doping ,021001 nanoscience & nanotechnology ,Ciências Naturais::Ciências Químicas ,0104 chemical sciences ,SILK ,thin films ,chemistry ,Chemical engineering ,silk fibroin ,Lithium ,0210 nano-technology - Abstract
We introduce a bio-inspired strategy for the synthesis of green polymer electrolytes (PEs) which relies on the use of silk fibroin (SF). The two series of PEs prepared, doped with lithium bis(trifluoromethanesulfonyl)imide (SF@LiTFSI) or lithium tetrafluoroborate (SF@LiBF4) and incorporating glycerol, exhibited outstanding filmogenic properties, very high transparency and suitable adhesion to glass substrates. Despite their poor ionic conductivity, the SF-based films (SF@) were employed in the construction of glass/ITO/WO3/SF@/CeO2-TiO2/ITO/glass electrochromic devices displaying an optical modulation up to 5.5 % at 633 nm, switching speed of ca. 15 s, stability up to 5160 cycles, and coloration efficiency up to −53.1 m2 C−1 . This work, in which we provide the proof-of-concept, paves the way for new design approaches for silk-based materials, enlarging the range of applications of SF to the energy field., This work was supported by Fundação para a Ciência e a Tecnologia (FCT) and Feder (contracts PTDC/CTMBPC/112774/2009, PEst-OE/QUI/UI0616/2014 and PEstC/QUI/UI0686/2013) and COST Action MP1202 “Rational design of hybrid organic-inorganic interfaces”. R.F.P.P. acknowledges FCT for a grant (SFRH/BPD/87759/2012). M.M.S. acknowledges Fundação Luso-Americana (FLAD) and CNPq (PVE grant 406617/2013-9), for a mobility grant., info:eu-repo/semantics/publishedVersion
- Published
- 2016
48. Non‐Newtonian Nanofluids: Non‐Newtonian Thermosensitive Nanofluid Based on Carbon Dots Functionalized with Ionic Liquids (Small 28/2020)
- Author
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Artur J.M. Valente, Helena Gonçalves, Emmanuel Lepleux, Louis Pacheco, Abel J. Duarte, Verónica de Zea Bermudez, and Rui F. P. Pereira
- Subjects
Materials science ,chemistry.chemical_element ,02 engineering and technology ,General Chemistry ,021001 nanoscience & nanotechnology ,Non-Newtonian fluid ,Biomaterials ,chemistry.chemical_compound ,Nanofluid ,020401 chemical engineering ,chemistry ,Chemical engineering ,Ionic liquid ,General Materials Science ,0204 chemical engineering ,0210 nano-technology ,Carbon ,Biotechnology - Published
- 2020
49. Non‐Newtonian Thermosensitive Nanofluid Based on Carbon Dots Functionalized with Ionic Liquids
- Author
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Verónica de Zea Bermudez, Artur J.M. Valente, Emmanuel Lepleux, Abel J. Duarte, Helena Gonçalves, Rui F. P. Pereira, Louis Pacheco, and Repositório Científico do Instituto Politécnico do Porto
- Subjects
Materials science ,Ionic Liquids ,02 engineering and technology ,Conductivity ,010402 general chemistry ,7. Clean energy ,01 natural sciences ,Nanofluids ,Biomaterials ,Viscosity ,chemistry.chemical_compound ,Nanofluid ,Self-improving ionic conductivity ,Carbon dots ,General Materials Science ,Surface plasmon resonance ,Electric Conductivity ,Imidazoles ,General Chemistry ,021001 nanoscience & nanotechnology ,Carbon ,Ionic liquids ,0104 chemical sciences ,Plasmonic effect ,chemistry ,Chemical engineering ,Ionic liquid ,Surface modification ,Wetting ,0210 nano-technology ,Trifluoromethanesulfonate ,Biotechnology - Abstract
Non-Newtonian nanofluids present outstanding features in terms of energy transfer and conductivity with high application in numerous areas. In this work, non-Newtonian nanofluids based on carbon dots (Cdots) functionalized with ionic liquids (ILs) are developed. The nanofluids are produced using a simple, single-step method where the raw materials for the Cdots synthesis are glucose and waste biomass (chitin from crab shells). The use of ILs as both reaction media and functionalization molecules allows for the development of a new class of nanofluids, where the ILs on the Cdots surface represent the base-fluid. Here, the well-known benign IL 1-butyl-3-methylimidazolium chloride ([Bmim]Cl) and a novel home-made IL (1-tosylate-3-methyl-imidazolium triflate) [Tmi][Trif] are used. The nanofluids obtained from both substrates show, apart from high conductivity and viscosity, light absorption, and good wettability, an appealing thermal sensitivity behavior. This thermal sensitivity is preserved even when applied as thin films on glass slides and can be boosted using the surface plasmon resonance effect. The results reported demonstrate that the new Cdots/IL-based nanofluids constitute a versatile and cost-effective route for achieving high-performance thermosensitive non-Newtonian sustainable nanofluids with tremendous potential for the energy coatings sector and heat transfer film systems., This research was funded by National Funds by Foundation for Science and Technology (FCT) and by FEDER funds through POCI-COMPETE 2020-Operational Programme Competitiveness and Internationalization in Axis I—Strengthening Research, Technological Development and Innovation (UID/QUI/00616/2013, UID/QUI/50006/2019, UID/ Multi/00709/2013, UID/QUI/00313/2019, UID/CTM/50025, POCI-01- 0145-FEDER-007491, POCI-01-0145-FEDER-007688, UID/CTM/50025, POCI-01-0145-FEDER-016884, PTDC/CTM-NAN/0956/2014, SAICT/ PAC/0032/2015, POCI-01-0145-FEDER-016422, and NORTE-01-0145- FEDER-030858). R.F.P.P. acknowledges FCT-MCTES for SFRH/ BPD/87759/2012 grant. E. Pereira (FCUP, Porto) is acknowledged for her assistance
- Published
- 2020
50. Development of Poly(l-Lactic Acid)-Based Bending Actuators
- Author
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Liliana Fernandes, Verónica de Zea Bermudez, Daniela M. Correia, Gabriela Botelho, Bárbara D. D. Cruz, Senentxu Lanceros-Méndez, and Universidade do Minho
- Subjects
Materials science ,Polymers and Plastics ,thermal treatments ,Composite number ,Ionic bonding ,Young's modulus ,02 engineering and technology ,Thermal treatment ,010402 general chemistry ,PLLA ,composites ,01 natural sciences ,Article ,lcsh:QD241-441 ,symbols.namesake ,Crystallinity ,chemistry.chemical_compound ,lcsh:Organic chemistry ,ionic liquid ,Science & Technology ,Dopant ,General Chemistry ,021001 nanoscience & nanotechnology ,Casting ,0104 chemical sciences ,degree of crystallinity ,Chemical engineering ,chemistry ,Ionic liquid ,symbols ,0210 nano-technology - Abstract
This work reports on the development of bending actuators based on poly(l-lactic acid) (PLLA)/ionic liquid (IL) blends, through the incorporation of 40% wt. of the 1-ethyl-methylimidazolium bis(trifluoromethylsulfonyl)imide ([Emim][TFSI]) IL. The films, obtained by solvent casting at room temperature and 50 °, C, were subjected to several post-thermal treatments at 70, 90, 120 and 140 °, C, in order to modify the crystallinity of the films. The influence of the drying temperature and of [Emim][TFSI] blending on the morphological, structural, mechanical and electrical properties of the composite materials were studied. The IL induced the formation of a porous surface independently of the processing conditions. Moreover, the [Emim][TFSI] dopant and the post-thermal treatments at 70 °, C promoted an increase of the degree of crystallinity of the samples. No significant changes were observed in the degree of crystallinity and Young Modulus for samples with thermal treatment between 70 and 140 °, C. The viability of the developed high ionic conductive blends for applications as soft actuators was evaluated. A maximum displacement of 1.7 mm was achieved with the PLLA/[Emim][TFSI] composite prepared at 50 °, C and thermally treated at 140 °, C, for an applied voltage of 10 Vpp, at a frequency of 100 mHz. This work highlights interesting avenues for the use of PLLA in the field of actuators.
- Published
- 2020
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