ORCID Profile
0000-0001-6791-7620
Current Organisations
Universidad Nacional de Educación a Distancia
,
Universidad del País Vasco
,
Universidade do Minho
,
Physikalisches Institut der Julius-Maximilians-Universität Würzburg, Germany
,
BCMaterials, Basque Center for Materials, Applications and Nanostructures
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Publications
Isothermal crystallization kinetics of poly(vinylidene fluoride) in the α-phase in the scope of the Avrami equation
Publisher: Springer Science and Business Media LLC
Date: 09-12-2009
Microscopic origin of the high-strain mechanical response of poled and non-poled poly(vinylidene fluoride) in the β-phase
Publisher: Elsevier BV
Date: 08-2008
Influence of processing parameters on the polymer phase, microstructure and macroscopic properties of poly(vinilidene fluoride)/Pb(Zr0.53Ti0.47)O3 composites
Publisher: Elsevier BV
Date: 09-2010
Origin of the ultra-wide temperature dielectric stability and dynamic behavior of nanoregions in 0.6Bi(Mg0.5Ti0.5)O3–0.4Ba0.8Ca0.2(Ti0.875
Publisher:
Royal Society of Chemistry (RSC)
Date:
2022
DOI:
10.1039/D2TC03037C
Abstract: The model of relaxation originating from the local structure.
Molecular Orientation and Degree of Crystallinity of Piezoelectric Poly(Vinylidene Fluoride) Films Exclusively in the β Phase
Publisher: Informa UK Limited
Date: 11-11-0100
Acetylated bacterial cellulose coated with urinary bladder matrix as a substrate for retinal pigment epithelium
Publisher: Elsevier BV
Date: 03-2016
DOI: 10.1016/J.COLSURFB.2015.11.051
Abstract: This work evaluated the effect of acetylated bacterial cellulose (ABC) substrates coated with urinary bladder matrix (UBM) on the behavior of retinal pigment epithelium (RPE), as assessed by cell adhesion, proliferation and development of cell polarity exhibiting transepithelial resistance and polygonal shaped-cells with microvilli. Acetylation of bacterial cellulose (BC) generated a moderate hydrophobic surface (around 65°) while the adsorption of UBM onto these acetylated substrates did not affect significantly the surface hydrophobicity. The ABS substrates coated with UBM enabled the development of a cell phenotype closer to that of native RPE cells. These cells were able to express proteins essential for their cytoskeletal organization and metabolic function (ZO-1 and RPE65), while showing a polygonal shaped morphology with microvilli and a monolayer configuration. The coated ABC substrates were also characterized, exhibiting low swelling effect (between 1.5-2.0 swelling/mm(3)), high mechanical strength (2048MPa) and non-pyrogenicity (2.12EU/L). Therefore, the ABC substrates coated with UBM exhibit interesting features as potential cell carriers in RPE transplantation that ought to be further explored.
Effect of the ceramic grain size and concentration on the dynamical mechanical and dielectric behavior of poly(vinilidene fluoride) Pb(Zr0.53Ti0.47)O3 composites
Publisher: Springer Science and Business Media LLC
Date: 09-07-2009
The effect of nanotube surface oxidation on the electrical properties of multiwall carbon nanotube/poly(vinylidene fluoride) composites
Publisher: Springer Science and Business Media LLC
Date: 13-07-2012
Piezoelectric polymers as biomaterials for tissue engineering applications
Publisher: Elsevier BV
Date: 12-2015
DOI: 10.1016/J.COLSURFB.2015.08.043
Abstract: Tissue engineering often rely on scaffolds for supporting cell differentiation and growth. Novel paradigms for tissue engineering include the need of active or smart scaffolds in order to properly regenerate specific tissues. In particular, as electrical and electromechanical clues are among the most relevant ones in determining tissue functionality in tissues such as muscle and bone, among others, electroactive materials and, in particular, piezoelectric ones, show strong potential for novel tissue engineering strategies, in particular taking also into account the existence of these phenomena within some specific tissues, indicating their requirement also during tissue regeneration. This referee reports on piezoelectric materials used for tissue engineering applications. The most used materials for tissue engineering strategies are reported together with the main achievements, challenges and future needs for research and actual therapies. This review provides thus a compilation of the most relevant results and strategies and a start point for novel research pathways in the most relevant and challenging open questions.
Effect of the carbon nanotube surface characteristics on the conductivity and dielectric constant of carbon nanotube/poly(vinylidene fluoride) composites
Publisher: Springer Science and Business Media LLC
Date: 07-04-2011
Abstract: Commercial multi-walled carbon nanotubes (CNT) were functionalized by oxidation with HNO 3 , to introduce oxygen-containing surface groups, and by thermal treatments at different temperatures for their selective removal. The obtained s les were characterized by adsorption of N 2 at -196°C, temperature-programmed desorption and determination of pH at the point of zero charge. CNT oly(vinylidene fluoride) composites were prepared using the above CNT s les, with different filler fractions up to 1 wt%. It was found that oxidation reduced composite conductivity for a given concentration, shifted the percolation threshold to higher concentrations, and had no significant effect in the dielectric response.
Development of electrospun photocatalytic TiO2-polyamide-12 nanocomposites
Publisher: Elsevier BV
Date: 08-2015
Effect of cyano dipolar groups on the performance of lithium-ion battery electrospun polyimide gel electrolyte membranes
Publisher: Elsevier BV
Date: 10-2016
Relationship between processing conditions, defects and thermal degradation of poly(vinylidene fluoride) in the β-phase
Publisher: Elsevier BV
Date: 2008
Bacterial cellulose-lactoferrin as an antimicrobial edible packaging
Publisher: Elsevier BV
Date: 07-2016
Influence of Silver Nanoparticles Concentration on the α- to β-Phase Transformation and the Physical Properties of Silver Nanoparticles Doped Poly(vinylidene fluoride) Nanocomposites
Publisher: American Scientific Publishers
Date: 02-05-2009
DOI: 10.1166/JNN.2009.208
Abstract: This paper describes the processing of silver nanoparticle doped poly(vinylidene fluoride). The effect of the dopant concentration on the alpha- to beta-phase transformation of the polymer as well as in the morphological, thermal, optical and dielectric properties of the nanocomposites was investigated. Spherical silver nanoparticles were incorporated into the poly(vinylidene fluoride) polymeric matrix by the solvent casting method, with different Ag concentrations. Well-dispersed Ag nanoparticles act as nucleation centers, increasing the degree of crystallinity of the nanocomposites. Homogeneous dispersion of silver nanoparticles is demonstrated through the presence of surface plasmon resonance absorption in the nanocomposites. The alpha- to beta-phase transformation was achieved in the polymer matrix and a maximum of approximately equal to 70% of beta-PVDF was reached at 80 degrees C and a stretching ratio of 400%. The dielectric constant of the nanocomposites increases with increasing metal nanoparticle concentration, up to approximately equal to 26 at 0.020 wt% Ag content. The alpha- to beta-phase transformation affects both the dielectric response and the surface plasmon resonance.
Local probing of magnetoelectric properties of PVDF/Fe3O4electrospun nanofibers by piezoresponse force microscopy
Publisher: IOP Publishing
Date: 06-01-2017
Abstract: The coupling of magnetic and electric properties in polymer-based magnetoelectric composites offers new opportunities to develop contactless electrodes, effectively without electrical connections, for less-invasive integration into devices such as energy harvesters, sensors, wearable and implantable electrodes. Understanding the macroscale-to-nanoscale conversion of the properties is important, as nanostructured and nanoscale magnetoelectric structures are increasingly fabricated. However, whilst the magnetoelectric effect at the macroscale is well established both theoretically and experimentally, it remains unclear how this effect translates to the nanoscale, or vice versa. Here, PVDF/Fe
Magnetoelectric CoFe2O4/polyvinylidene fluoride electrospun nanofibres
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5NR00453E
Abstract: Magnetoelectric 0-1 composites comprising CoFe2O4 (CFO) nanoparticles in a polyvinylidene fluoride (PVDF) polymer-fibre matrix have been prepared by electrospinning. The average diameter of the electrospun composite fibres is ∼325 nm, independent of the nanoparticle content, and the amount of the crystalline polar β phase is strongly enhanced when compared to pure PVDF polymer fibres. The piezoelectric response of these electroactive nanofibres is modified by an applied magnetic field, thus evidencing the magnetoelectric character of the CFO/PVDF 0-1 composites.
Effect of the ceramic grain size and concentration on the dynamical mechanical and dielectric behavior of poly(vinilidene fluoride)/Pb(Zr0.53Ti0.47)O3 composites
Publisher: Springer Science and Business Media LLC
Date: 04-03-2009
The effect of fibre concentration on the α to β-phase transformation, degree of crystallinity and electrical properties of vapour grown carbon nanofibre/poly(vinylidene fluoride) composites
Publisher: Elsevier BV
Date: 09-2009
Assessment of parameters influencing fiber characteristics of chitosan nanofiber membrane to optimize fiber mat production
Publisher: Wiley
Date: 17-02-2007
DOI: 10.1002/PEN.23070
Synthesis of highly magnetostrictive nanostructures and their application in a polymer-based magnetoelectric sensing device
Publisher: Elsevier BV
Date: 11-2016
Processing and characterization of α-elastin electrospun membranes
Publisher: Springer Science and Business Media LLC
Date: 26-09-2013
Suitability of PLLA as Piezoelectric Substrates for Tissue Engineering Evidenced by Microscopy Techniques
Publisher: Oxford University Press (OUP)
Date: 08-2012
DOI: 10.1017/S1431927612012974
Abstract: Since the discovery of the piezoelectric character of bone, the suitability of some piezoelectric materials have been studied for bone repair they are thought to act like transducers converting the mechanical energy of skeletal deformation in electrical stimuli capable of controlling osteogenic growth. The mechanisms underlying this process are far from being understood and systematic studies at a local scale are required. Atomic force microscopy (AFM) is a unique way to observe phenomena at the nanoscale and liquid imaging provides a unique tool to assess biological phenomena at the nanoscale. So in this study, aiming at a better understanding of the role of piezoelectricity in the osteogenic growth, the interaction between a poled piezoelectric material, in this case poly (L-lactic) acid and an adhesion promoting protein, the fibronectin, and bone-like cells is evaluated by scanning probe microscopy and confocal laser scanning microscopy (CLSM).
Correction to Bacterial Cellulose As a Support for the Growth of Retinal Pigment Epithelium
Publisher: American Chemical Society (ACS)
Date: 12-04-2021
Fibronectin adsorption and cell response on electroactive poly(vinylidene fluoride) films
Publisher: IOP Publishing
Date: 23-02-2012
DOI: 10.1088/1748-6041/7/3/035004
Abstract: Due to the large potential of electroactive materials in novel tissue engineering strategies, the aim of this work is to determine if the crystalline phase and/or the surface electrical charge of electroactive poly(vinylidene fluoride), PVDF, have influence on the biological response in monolayer cell culture. Non-polar α-PVDF and electroactive β-PVDF were prepared. The β-PVDF films were poled by corona discharge to show negative or positive electrical surface charge density. It has been concluded that hydrophilicity of the PVDF substrates depends significantly on crystalline phase and polarity. Furthermore, by means of atomic force microscopy and an enzyme-linked immunosorbent assay test, it has been shown that positive or negative poling strongly influences the behavior of β-PVDF supports with respect to fibronectin (FN) adsorption, varying the exhibition of adhesion ligands of adsorbed FN. Culture of MC3T3-E1 pre-osteoeblasts proved that cell proliferation depends on surface polarity as well. These results open the viability of cell culture stimulation by mechanical deformation of a piezoelectric substrate that results in varying electrical charge densities on the substrate surface.
Thermal, dielectrical and mechanical response of α and β-poly(vinilydene fluoride)/Co-MgO nanocomposites
Publisher: Springer Science and Business Media LLC
Date: 25-03-2011
Abstract: Nanocomposites of the self-forming core-shell Co-MgO nanoparticles, which were of approximately 100 nm in diameter, and poly(vinylidene fluoride) (PVDF) polymer have been prepared. When the polymer is crystallized in the α-phase, the introduction of the nanoparticles leads to nucleation of the γ-phase of PVDF, increasing also the melting temperature of the polymer. With the introduction of the Co-MgO particles, the dielectric constant of the material slightly increases and the storage modulus decreases with respect to the values obtained for the pure polymer.
Effect of poling state and morphology of piezoelectric poly(vinylidene fluoride) membranes for skeletal muscle tissue engineering
Publisher: Royal Society of Chemistry (RSC)
Date: 2013
DOI: 10.1039/C3RA43499K
Evaluation of the main processing parameters influencing the performance of poly(vinylidene fluoride–trifluoroethylene) lithium-ion battery separators
Publisher: Springer Science and Business Media LLC
Date: 16-11-2012
Sustainable Bio-Based Epoxy Resins with Tunable Thermal and Mechanic Properties and Superior Anti-Corrosion Performance
Publisher: MDPI AG
Date: 21-10-2023
Strategies for the development of three dimensional scaffolds from piezoelectric poly(vinylidene fluoride)
Publisher: Elsevier BV
Date: 02-2016
Piezoelectric poly(vinylidene fluoride) microstructure and poling state in active tissue engineering
Publisher: Wiley
Date: 19-01-2015
Poly(vinylidene fluoride-trifluoroethylene) (72/28) interconnected porous membranes obtained by crystallization from solution
Publisher: Springer Science and Business Media LLC
Date: 2011
DOI: 10.1557/OPL.2011.914
Abstract: Electroactive macroporous poly[(vinylidene fluoride)-co-trifluoroethylene] membranes have been processed by solvent evaporation at room temperature with different polymer/solvent concentrations. The pore architecture consists on interconnected spherical pores and this morphology is independent of the membrane thickness. The porosity of the produced membranes increases from 72% for the higher polymer concentration in the polymer/solvent solution (15/85), up to 80% for the lowest polymer concentration in the polymer/solvent solution. Fourier transform infrared spectroscopy and differential scanning calorimetry measurements reveal that the polymer crystallizes in the ferroelectric phase and the polymer/solvent ratio does not influences the Curie transition and the melting temperature of the polymer.
Modifying Fish Gelatin Electrospun Membranes for Biomedical Applications: Cross-Linking and Swelling Behavior
Publisher: Informa UK Limited
Date: 03-07-2014
Surface roughness dependent osteoblast and fibroblast response on poly(l -lactide) films and electrospun membranes
Publisher: Wiley
Date: 11-11-2014
DOI: 10.1002/JBM.A.35367
Abstract: Poly(l-lactide) electrospun mats with random and aligned fiber orientation and films have been produced with degrees of crystallinity ranging from 0 up to nearly 50%. The overall surface roughness is practically constant irrespective of the s ling areas (1 × 1 µm to 20 × 20 µm) for degrees of crystallinity below 30%, increasing for higher degrees of crystallinity for the larger s ling areas. Further, due to fiber confinement, surface roughness variations are smaller in electrospun mats. S les with 50% of crystallinity show the lowest osteoblast and the highest fibroblast proliferation. Therefore, it is verified that higher roughness promotes lower osteoblast but higher fibroblast proliferation. The overall results indicate the relevant role of the sub-microenvironment variations associated to the microscale roughness in determining the different cell responses.
Dynamic piezoelectric stimulation enhances osteogenic differentiation of human adipose stem cells
Publisher: Wiley
Date: 11-11-2014
DOI: 10.1002/JBM.A.35368
Abstract: This work reports on the influence of the substrate polarization of electroactive β-poly(vinylidene fluoride) (β-PVDF) on human adipose stem cells (hASCs) differentiation under static and dynamic conditions. hASCs were cultured on different β-PVDF surfaces (non-poled and "poled -") adsorbed with fibronectin and osteogenic differentiation was determined using a quantitative alkaline phosphatase assay. "Poled -" β-PVDF s les promote higher osteogenic differentiation, which is even higher under dynamic conditions. It is thus demonstrated that electroactive membranes can provide the necessary electromechanical stimuli for the differentiation of specific cells and therefore will support the design of suitable tissue engineering strategies, such as bone tissue engineering.
Processing and characterization of a novel nonporous poly(vinilidene fluoride) films in the β phase
Publisher: Elsevier BV
Date: 07-2006
PHB-PEO electrospun fiber membranes containing chlorhexidine for drug delivery applications
Publisher: Elsevier BV
Date: 04-2014
Fiber average size and distribution dependence on the electrospinning parameters of poly(vinylidene fluoride–trifluoroethylene) membranes for biomedical applications
Publisher: Springer Science and Business Media LLC
Date: 17-08-2012
Liquid Flow Sensor Based on PVDF in its Beta Phase
Publisher: IEEE
Date: 06-2007
Electrospun styrene–butadiene–styrene elastomer copolymers for tissue engineering applications: Effect of butadiene/styrene ratio, block structure, hydrogenation and carbon nanotube loading on physica
Publisher: Elsevier BV
Date: 12-2014
Thermal and hydrolytic degradation of electrospun fish gelatin membranes
Publisher: Elsevier BV
Date: 08-2013
Influence of crystallinity and fiber orientation on hydrophobicity and biological response of poly(l-lactide) electrospun mats
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2SM25557J
Energy harvesting performance of piezoelectric electrospun polymer fibers and polymer/ceramic composites
Publisher: Elsevier BV
Date: 07-2013
Synthesis, physical and magnetic properties of BaFe12O19/P(VDF-TrFE) multifunctional composites
Publisher: Elsevier BV
Date: 08-2015
Development of poly(vinylidene fluoride)/ionic liquid electrospun fibers for tissue engineering applications
Publisher: Springer Science and Business Media LLC
Date: 29-01-2016
Osteoblast, fibroblast and in vivo biological response to poly(vinylidene fluoride) based composite materials
Publisher: Springer Science and Business Media LLC
Date: 09-11-2012
DOI: 10.1007/S10856-012-4808-Y
Abstract: Electroactive materials can be taken to advantage for the development of sensors and actuators as well as for novel tissue engineering strategies. Composites based on poly(vinylidene fluoride), PVDF, have been evaluated with respect to their biological response. Cell viability and proliferation were performed in vitro both with Mesenchymal Stem Cells differentiated to osteoblasts and Human Fibroblast Foreskin 1. In vivo tests were also performed using 6-week-old C57Bl/6 mice. It was concluded that zeolite and clay composites are biocompatible materials promoting cell response and not showing in vivo pro-inflammatory effects which renders both of them attractive for biological applications and tissue engineering, opening interesting perspectives to development of scaffolds from these composites. Ferrite and silver nanoparticle composites decrease osteoblast cell viability and carbon nanotubes decrease fibroblast viability. Further, carbon nanotube composites result in a significant increase in local vascularization accompanied an increase of inflammatory markers after implantation.
Mechanical Characterization and Influence of the High Temperature Shrinkage of β-PVDF Films on its Electromechanical Properties
Publisher: Informa UK Limited
Date: 2003
Design and validation of a biomechanical bioreactor for cartilage tissue culture
Publisher: Springer Science and Business Media LLC
Date: 08-07-2015
DOI: 10.1007/S10237-015-0698-5
Abstract: Specific tissues, such as cartilage, undergo mechanical solicitation under their normal performance in human body. In this sense, it seems necessary that proper tissue engineering strategies of these tissues should incorporate mechanical solicitations during cell culture, in order to properly evaluate the influence of the mechanical stimulus. This work reports on a user-friendly bioreactor suitable for applying controlled mechanical stimulation-- litude and frequency--to three-dimensional scaffolds. Its design and main components are described, as well as its operation characteristics. The modular design allows easy cleaning and operating under laminar hood. Different protocols for the sterilization of the hermetic enclosure are tested and ensure lack of observable contaminations, complying with the requirements to be used for cell culture. The cell viability study was performed with KUM5 cells.
Bacterial Cellulose As a Support for the Growth of Retinal Pigment Epithelium
Publisher: American Chemical Society (ACS)
Date: 12-03-2015
DOI: 10.1021/ACS.BIOMAC.5B00129
Abstract: The feasibility of bacterial cellulose (BC) as a novel substrate for retinal pigment epithelium (RPE) culture was evaluated. Thin (41.6 ± 2.2 μm of average thickness) and heat-dried BC substrates were surface-modified via acetylation and polysaccharide adsorption, using chitosan and carboxymethyl cellulose. All substrates were characterized according to their surface chemistry, wettability, energy, topography, and also regarding their permeability, dimensional stability, mechanical properties, and endotoxin content. Then, their ability to promote RPE cell adhesion and proliferation in vitro was assessed. All surface-modified BC substrates presented similar permeation coefficients with solutes of up to 300 kDa. Acetylation of BC decreased it's swelling and the amount of endotoxins. Surface modification of BC greatly enhanced the adhesion and proliferation of RPE cells. All s les showed similar stress-strain behavior BC and acetylated BC showed the highest elastic modulus, but the latter exhibited a slightly smaller tensile strength and elongation at break as compared to pristine BC. Although similar proliferation rates were observed among the modified substrates, the acetylated ones showed higher initial cell adhesion. This difference may be mainly due to the moderately hydrophilic surface obtained after acetylation.
Functionally graded electroactive Poly(vinylidene fluoride) polymers
Publisher: Inderscience Publishers
Date: 2010
PVD-Grown photocatalytic TiO2 thin films on PVDF substrates for sensors and actuators applications
Publisher: Elsevier BV
Date: 12-2008
Enhanced proliferation of pre-osteoblastic cells by dynamic piezoelectric stimulation
Publisher: Royal Society of Chemistry (RSC)
Date: 2012
DOI: 10.1039/C2RA21841K
Extrusion of poly(vinylidene fluoride) filaments: effect of the processing conditions and conductive inner core on the electroactive phase content and mechanical properties
Publisher: Springer Science and Business Media LLC
Date: 12-06-2001
Piezoresistive sensors for force mapping of hip-prostheses
Publisher: Elsevier BV
Date: 06-2013
α- and γ-PVDF: Crystallization kinetics, microstructural variations and thermal behaviour
Publisher: Elsevier BV
Date: 07-2010
Bioactive albumin functionalized polylactic acid membranes for improved biocompatibility
Publisher: Elsevier BV
Date: 10-2013
Effect of degree of porosity on the properties of poly(vinylidene fluoride–trifluorethylene) for Li-ion battery separators
Publisher: Elsevier BV
Date: 07-2012
Electrical properties of intrinsically conductive core–shell polypyrrole/poly(vinylidene fluoride) electrospun fibers
Publisher: Elsevier BV
Date: 11-2014
Electrical Response of β-PVDF in a Constant Uniaxial Strain Rate Deformation
Publisher: Informa UK Limited
Date: 2004
Influence of Ferrite Nanoparticle Type and Content on the Crystallization Kinetics and Electroactive Phase Nucleation of Poly(vinylidene fluoride)
Publisher: American Chemical Society (ACS)
Date: 05-05-2011
DOI: 10.1021/LA2008864
Abstract: This work reports on the nucleation of the β-phase of poly(vinylidene fluoride) (PVDF) by incorporating CoFe(2)O(4) and NiFe(2)O(4) nanoparticles, leading in this way to the preparation of magnetoelectric composites. The fraction of filler nanoparticles needed to produce the same β- to α-phase ratio in crystallized PVDF is 1 order of magnitude lower in the cobalt ferrite nanoparticles. The interaction between nanoparticles and PVDF chains induce the all-trans conformation in PVDF segments, and this structure then propagates in crystal growth. The nucleation kinetics is enhanced by the presence of nanoparticles, as corroborated by the increasing number of spherulites with increasing nanoparticle content and by the variations of the Avrami's exponent. Further, the decrease of the crystalline fraction of PVDF with increasing nanoparticle content indicates that an important fraction of polymer chains are confined in interphases with the filler particle.
Electroactive Poly(Vinylidene Fluoride-Trifluorethylene) (PVDF-TrFE) Microporous Membranes for Lithium-Ion Battery Applications
Publisher: Informa UK Limited
Date: 2012
Effect of neutralization and cross-linking on the thermal degradation of chitosan electrospun membranes
Publisher: Springer Science and Business Media LLC
Date: 18-03-2014
Exploring the Properties of Genetically Engineered Silk‐Elastin‐Like Protein Films
Publisher: Wiley
Date: 27-07-2015
Abstract: Free standing films of a genetically engineered silk-elastin-like protein (SELP) were prepared using water and formic acid as solvents. Exposure to methanol-saturated air promoted the formation of aggregated β-strands rendering aqueous insolubility and improved the mechanical properties leading to a 10-fold increase in strain-to-failure. The films were optically clear with resistivity values similar to natural rubber and thermally stable up to 180 °C. Addition of glycerol showed to enhance the flexibility of SELP/glycerol films by interacting with SELP molecules through hydrogen bonding, interpenetrating between the polymer chains and granting more conformational freedom. This detailed characterization provides cues for future and unique applications using SELP based biopolymers.
Carbon nanofiber type and content dependence of the physical properties of carbon nanofiber reinforced polypropylene composites
Publisher: Wiley
Date: 26-03-2013
DOI: 10.1002/PEN.23539
Antibacterial performance of bovine lactoferrin-fish gelatine electrospun membranes
Publisher: Elsevier BV
Date: 11-2015
DOI: 10.1016/J.IJBIOMAC.2015.08.047
Abstract: The increase of antibiotic resistant microorganisms urged the development and synthesis of novel antimicrobial biomaterials to be employed in a broad range of applications, ranging from food packaging to medical devices. This work describes the production and characterization of a protein-based electrospun fibrous membranes bearing antimicrobial properties. Its composition is exclusively comprised of proteins, with fish gelatine as structural matrix and bovine lactoferrin (bLF) as the active antimicrobial agent. The bLF bactericidal effect was determined against clinical isolates of Escherichia coli and Staphylococcus aureus through microdilution assays. Two distinctive methods were used to incorporate bLF into the fish gelatine nanofibres: (i) as a filler in the electrospinning formulation with concentrations of 2, 5 and 10 (wt%), and cross-linked with glutaraldehyde vapour, in order to achieve stability in aqueous solution and (ii) through adsorption in a solution with 40mgmL(-1) bLF. Fourier transform infrared spectroscopy analysis showed that the structure of both proteins remained intact through the electrospinning blending and cross-linking procedure. Remarkable antibacterial properties were obtained with membranes containing 5% and 10% bLF with a bacterial reduction of approximately 90% and 100%, respectively.
Thermal characterization of a vinylidene fluoride-trifluorethylene (75–25) (%mol) copolymer film
Publisher: Elsevier BV
Date: 12-2006
Ultrahigh thermal stability of dielectric permittivity in 0.6Bi(Mg1/2Ti1/2)O3–0.4Ba0.8Ca0.2(Ti0.875Nb0.125)O3
Publisher: AIP Publishing
Date: 06-2023
DOI: 10.1063/5.0146908
Abstract: 0.6Bi(Mg1/2Ti1/2)O3–0.4Ba0.8Ca0.2(Nb0.125Ti0.875)O3 ceramics with a pseudo-cubic structure and re-entrant dipole glass behavior have been investigated via x-ray diffraction and dielectric permittivity–temperature spectra. It shows excellent dielectric–temperature stability with small variations of dielectric permittivity (±5%, 420–802 K) and dielectric loss tangent (tanδ & 2.5%, 441–647 K) in a wide temperature range. Three dielectric anomalies are observed from 290 to 1050 K. The low-temperature, weakly coupled re-entrant relaxor behavior was described using the Vogel–Fulcher law and the new glass model. The mid- and high-temperature dielectric anomalies are characterized by isothermal impedance and electrical modulus. The activation energy of both dielectric relaxation and conductivity follows the Arrhenius law in the temperature ranges of 633–753 and 833–973 K, respectively. The ultrahigh thermal stability of dielectric permittivity is attributed to the weak coupling of polar clusters, the formation of diffuse phase transition, and the local phase transition of calcium-containing perovskite. The results provide new insights into the defects behavior and the modification way of re-entrant relaxor behavior.
Large Area Microfabrication of Electroactive Polymeric Structures Based on Near-Field Electrospinning
Publisher: Elsevier BV
Date: 2011
Energy harvesting performance of BaTiO3/poly(vinylidene fluoride–trifluoroethylene) spin coated nanocomposites
Publisher: Elsevier BV
Date: 04-2015
Dynamic mechanical analysis and creep behaviour of β-PVDF films
Publisher: Elsevier BV
Date: 04-2004
Fatigue prediction in fibrin poly-ε-caprolactone macroporous scaffolds
Publisher: Elsevier BV
Date: 12-2013
DOI: 10.1016/J.JMBBM.2013.07.011
Abstract: Tissue engineering applications rely on scaffolds that during its service life, either for in-vivo or in vitro applications, are under loading. The variation of the mechanical condition of the scaffold is strongly relevant for cell culture and has scarcely been addressed. The fatigue life cycle of poly-ε-caprolactone, PCL, scaffolds with and without fibrin as filler of the pore structure were characterized both dry and immersed in liquid water. It is observed that the there is a strong increase from 100 to 500 in the number of loading cycles before collapse in the s les tested in immersed conditions due to the more uniform stress distributions within the s les, the fibrin loading playing a minor role in the mechanical performance of the scaffolds.
Influence of filler size and concentration on the low and high temperature dielectric response of poly(vinylidene fluoride) /Pb(Zr0.53Ti0.47)O3 composites
Publisher: Springer Science and Business Media LLC
Date: 09-2012
Thermal Properties of Electrospun Poly(Lactic Acid) Membranes
Publisher: Informa UK Limited
Date: 19-08-2011
Strain analysis of photocatalytic TiO2 thin films on polymer substrates
Publisher: Elsevier BV
Date: 02-2008
Performance of electroactive poly(vinylidene fluoride) against UV radiation
Publisher: Elsevier BV
Date: 10-2008
Fabrication of Poly(lactic acid)-Poly(ethylene oxide) Electrospun Membranes with Controlled Micro to Nanofiber Sizes
Publisher: American Scientific Publishers
Date: 08-2012
Abstract: Biodegradable poly(L-lactide acid) (PLLA) nanofiber membranes were prepared by electrospinning of PLLA and poly(ethylene oxide) (PEO). The selective removal of PEO by water allows to obtain smaller fiber diameters and to increase the porosity of the membranes in comparison to PLLA membranes obtained under the same electrospinning conditions. After removal of PEO membranes with fiber sizes of 260 nm and average porosity close to 80% are obtained. Thermal and infrared results confirm the poor miscibility of PLLA and PEO, with the PEO randomly distributed along the PLLA fibers. On the other, PLLA and PEO mixing strongly affect their respective degradation temperatures. The influence of the PEO in the electrospinning process is discussed and the results are correlated to the evolution of the PLLA fiber diameter.
Development of magnetoelectric CoFe2O4 /poly(vinylidene fluoride) microspheres
Publisher: Royal Society of Chemistry (RSC)
Date: 2015
DOI: 10.1039/C5RA04409J
Abstract: Magnetoelectric microspheres based on piezoelectric poly(vinylidene fluoride) (PVDF) and magnetostrictive CoFe 2 O 4 (CFO), a novel morphology for polymer-based ME materials, have been developed by an electrospray process.
Kinetic study of thermal degradation of chitosan as a function of deacetylation degree
Publisher: Elsevier BV
Date: 07-2017
DOI: 10.1016/J.CARBPOL.2017.03.020
Abstract: Thermal degradation of chitosan with varying deacetylation degree (DD) ranging between 50 and 85% was analyzed by dynamic thermogravimetric analysis at different heating rates. The present study focused on the temperature range between 500 and 800K, above water evaporation. Thermal degradation showed a main degradation stage in this temperature interval with a second stage that appeared in the weight derivative curves as a shoulder in the high temperature side of the main peak with increasing intensity as the DD decreased. The Kissinger and isoconversional Ozawa-Flynn-Wall models were employed to evaluate the Ea of both thermal degradation processes. Different kinetic models were tested to computer simulate the thermogravimetric traces calculating the model parameters with a non-linear least squares fitting routine. The Sestack-Berggren model allowed reproducing accurately the overlapping of the two degradation mechanisms and calculating the mass fraction lost in each of them revealing the coupling between the two degradation mechanisms.
Enhancement of adhesion and promotion of osteogenic differentiation of human adipose stem cells by poled electroactive poly(vinylidene fluoride)
Publisher: Wiley
Date: 29-05-2014
DOI: 10.1002/JBM.A.35234
Abstract: Poly(vinylidene fluoride) (PVDF) is a biocompatible material with excellent electroactive properties. Nonelectroactive α-PVDF and electroactive β-PVDF were used to investigate the substrate polarization and polarity influence on the focal adhesion (FA) size and number as well as on human adipose stem cells (hASCs) differentiation. hASCs were cultured on different PVDF surfaces adsorbed with fibronectin and FA size and number, total adhesion area, cell size, cell aspect ratio and FA density were estimated using cells expressing vinculin fused to enhanced green fluorescent protein. Osteogenic differentiation was also determined using a quantitative alkaline phosphatase assay. The surface charge of the poled PVDF films (positive or negative) influenced the hydrophobicity of the s les, leading to variations in the conformation of adsorbed extracellular matrix proteins, which ultimately modulated the stem cell adhesion on the films and induced their osteogenic differentiation.
TiO2/graphene oxide immobilized in P(VDF-TrFE) electrospun membranes with enhanced visible-light-induced photocatalytic performance
Publisher: Springer Science and Business Media LLC
Date: 25-04-2016
Behaviour of the Ferroelectric Phase Transition of P(VDF/TrFE) (75/25) with Increasing Deformation
Publisher: Informa UK Limited
Date: 2004
Metal–organic frameworks and zeolite materials as active fillers for lithium-ion battery solid polymer electrolytes
Publisher: Royal Society of Chemistry (RSC)
Date: 2021
DOI: 10.1039/D1MA00244A
Abstract: The application of microporous structures as active fillers for solid polymer electrolytes (SPEs) affects battery performance and this review presents the state of the art of microporous materials (MOFs and zeolites) for SPE in solid-state batteries.
Mechanical, electrical and electro-mechanical properties of thermoplastic elastomer styrene–butadiene–styrene/multiwall carbon nanotubes composites
Publisher: Springer Science and Business Media LLC
Date: 07-09-2012
Influence of electrospinning parameters on poly(hydroxybutyrate) electrospun membranes fiber size and distribution
Publisher: Wiley
Date: 30-07-2013
DOI: 10.1002/PEN.23704
Characterization of poled and non-poled β-PVDF films using thermal analysis techniques
Publisher: Elsevier BV
Date: 12-2004
Tailoring the morphology and crystallinity of poly(L-lactide acid) electrospun membranes
Publisher: Informa UK Limited
Date: 02-2011
Effect of fiber orientation in gelled poly(vinylidene fluoride) electrospun membranes for Li-ion battery applications
Publisher: Springer Science and Business Media LLC
Date: 11-06-2013
Local piezoelectric activity of single poly(L-lactic acid) (PLLA) microfibers
Publisher: Springer Science and Business Media LLC
Date: 11-08-2012
Processing and size range separation of pristine and magnetic poly( l -lactic acid) based microspheres for biomedical applications
Publisher: Elsevier BV
Date: 08-2016
DOI: 10.1016/J.JCIS.2016.05.012
Abstract: Biodegradable poly(l-lactic acid) (PLLA) and PLLA/CoFe2O4 magnetic microspheres with average sizes ranging between 0.16-3.9μm and 0.8-2.2μm, respectively, were obtained by an oil-in-water emulsion method using poly(vinyl alcohol) (PVA) solution as the emulsifier agent. The separation of the microspheres in different size ranges was then performed by centrifugation and the colloidal stability assessed at different pH values. Neat PLLA spheres are more stable in alkaline environments when compared to magnetic microspheres, both types being stable for pHs higher than 4, resulting in a colloidal suspension. On the other hand, in acidic environments the microspheres tend to form aggregates. The neat PLLA microspheres show a degree of crystallinity of 40% whereas the composite ones are nearly amorphous (17%). Finally, the biocompatibility was assessed by cell viability studies with MC3T3-E1 pre-osteoblast cells.
Tailoring porous structure of ferroelectric poly(vinylidene fluoride-trifluoroethylene) by controlling solvent/polymer ratio and solvent evaporation rate
Publisher: Elsevier BV
Date: 12-2011
Magnetoelectric coupling in nanoscale 0–1 connectivity
Publisher: Royal Society of Chemistry (RSC)
Date: 2018
DOI: 10.1039/C8NR05182H
Abstract: Magnetoelectric coupling in novel 0–1 connectivity, allowing the use of nanomaterials to fabricate ME composites.
Local piezoelectric response of single poly(vinylidene fluoride) electrospun fibers
Publisher: Wiley
Date: 29-03-1970
In vitro mechanical fatigue behavior of poly‐ɛ‐caprolactone macroporous scaffolds for cartilage tissue engineering: Influence of pore filling by a poly(vinyl alcohol) gel
Publisher: Wiley
Date: 17-09-2014
DOI: 10.1002/JBM.B.33276
Abstract: Polymeric scaffolds used in regenerative therapies are implanted in the damaged tissue and submitted to repeated loading cycles. In the case of articular cartilage engineering, an implanted scaffold is typically subjected to long-term dynamic compression. The evolution of the mechanical properties of the scaffold during bioresorption has been deeply studied in the past, but the possibility of failure due to mechanical fatigue has not been properly addressed. Nevertheless, the macroporous scaffold is susceptible to failure after repeated loading-unloading cycles. In this work fatigue studies of polycaprolactone scaffolds were carried by subjecting the scaffold to repeated compression cycles in conditions simulating the scaffold implanted in the articular cartilage. The behavior of the polycaprolactone sponge with the pores filled with a poly(vinyl alcohol) gel simulating the new formed tissue within the pores was compared with that of the material immersed in water. Results were analyzed with Morrow's criteria for failure and accurate fittings are obtained just up to 200 loading cycles. It is also shown that the presence of poly(vinyl alcohol) increases the elastic modulus of the scaffolds, the effect being more pronounced with increasing the number of freeze/thawing cycles.
Degradation of the dielectric and piezoelectric response of β-poly(vinylidene fluoride) after temperature annealing
Publisher: Springer Science and Business Media LLC
Date: 06-01-2011
Low percolation transitions in carbon nanotube networks dispersed in a polymer matrix: dielectric properties, simulations and experiments
Publisher: IOP Publishing
Date: 17-12-2008
DOI: 10.1088/0957-4484/20/3/035703
Abstract: The low concentration behaviour and the increase of the dielectric constant in carbon nanotubes olymer nanocomposites near the percolation threshold are still not well understood. In this work, a numerical model has been developed which focuses on the effect of the inclusion of conductive fillers in a dielectric polymer matrix on the dielectric constant and the dielectric strength. Experiments have been carried out in carbon nanotubes oly(vinylidene fluoride) nanocomposites in order to compare to the simulation results. This work shows how the critical concentration is related to the formation of capacitor networks and that these networks give rise to high variations in the electrical properties of the composites. Based on numerical studies, the dependence of the percolation transition on the preparation of the nanocomposite is discussed. Finally, based on numerical and experimental results, both ours and from other authors, the causes of anomalous percolation behaviour of the dielectric constant are identified.
Influence of oxygen plasma treatment parameters on poly(vinylidene fluoride) electrospun fiber mats wettability
Publisher: Elsevier BV
Date: 08-2015
Influence of the β-phase content and degree of crystallinity on the piezo- and ferroelectric properties of poly(vinylidene fluoride)
Publisher: IOP Publishing
Date: 11-07-0004
Influence of fiber diameter and crystallinity on the stability of electrospun poly(l-lactic acid) membranes to hydrolytic degradation
Publisher: Elsevier BV
Date: 09-2012
The piezoresistive effect in polypropylene—carbon nanofibre composites obtained by shear extrusion
Publisher: IOP Publishing
Date: 04-05-2010
Electro-mechanical properties of triblock copolymer styrene–butadiene–styrene/carbon nanotube composites for large deformation sensor applications
Publisher: Elsevier BV
Date: 10-2013
Cellulose-based magnetoelectric composites
Publisher: Springer Science and Business Media LLC
Date: 28-06-2017
DOI: 10.1038/S41467-017-00034-4
Abstract: Since the first magnetoelectric polymer composites were fabricated more than a decade ago, there has been a reluctance to use piezoelectric polymers other than poly(vinylidene fluoride) and its copolymers due to their well-defined piezoelectric mechanism and high piezoelectric coefficients that lead to superior magnetoelectric coefficients of V cm −1 Oe −1 . This is the current situation despite the potential for other piezoelectric polymers, such as natural biopolymers, to bring unique, added-value properties and functions to magnetoelectric composite devices. Here we demonstrate a cellulose-based magnetoelectric laminate composite that produces considerable magnetoelectric coefficients of ≈1.5 V cm −1 Oe −1 , comprising a Fano resonance that is ubiquitous in the field of physics, such as photonics, though never experimentally observed in magnetoelectric composites. The work successfully demonstrates the concept of exploring new advances in using biopolymers in magnetoelectric composites, particularly cellulose, which is increasingly employed as a renewable, low-cost, easily processable and degradable material.
Effect of filler content on morphology and physical–chemical characteristics of poly(vinylidene fluoride)/NaY zeolite-filled membranes
Publisher: Springer Science and Business Media LLC
Date: 29-01-2014
Relationship between the microstructure and the microscopic piezoelectric response of the α- and β-phases of poly(vinylidene fluoride)
Publisher: Springer Science and Business Media LLC
Date: 04-02-2009
Relaxation dynamics of poly(vinylidene fluoride) studied by dynamical mechanical measurements and dielectric spectroscopy
Publisher: Springer Science and Business Media LLC
Date: 05-2012
DOI: 10.1140/EPJE/I2012-12041-X
Abstract: The aim of this study is to analyze the mobility of polymer chains in semicrystalline poly(vinylidene fluoride) (PVDF). PVDF crystallizes from the melt in the α crystalline phase. The transformation from the α phase to the electroactive β phase can be induced by stretching at temperatures in the range between 80 and 140 °C. The spherulitic structure of the crystalline phase is deformed during stretching to form fibrils oriented in the direction of the strain. The amorphous phase confined among the crystalline lamellae is distorted as well and some degree of orientation of the polymer chains is expected. Dynamic-mechanical and dielectric spectroscopy measurements were performed in PVDF films stretched to strain ratios up to 5 at temperatures between 80 and 140 °C. Dynamic-mechanical measurements were conducted between -60 °C and melting and in this temperature range the relaxation spectra show the main relaxation of the amorphous phase (called β-relaxation) and at higher temperatures a relaxation related to crystallites motions (α (c)-relaxation). Although the mean relaxation times of the β-relaxation are nearly equal in PVDF before and after crystal phase transformation, a significant change of shape of the relaxation spectrum proves the effect of chain distortion due to crystal reorganization. In stretched PVDF the elastic modulus of the polymer in the direction of deformation is significantly higher than in the transversal one, as expected by chain and crystals fibril orientation. The recovery of the deformation when the s le is heated is related with the appearance of the α (c)-relaxation. Dielectric spectroscopy spectrum shows the main relaxation of the amorphous phase and a secondary process (γ-relaxation) at lower temperatures. Stretching produces significant changes in the relaxation processes, mainly in the strength and shape of the main relaxation β. The Havriliak-Negami function has been applied to analyze the dielectric response.
The Role of Solvent Evaporation in the Microstructure of Electroactive β-Poly(Vinylidene Fluoride) Membranes Obtained by Isothermal Crystallization
Publisher: Informa UK Limited
Date: 06-12-2010
Physical-chemical properties of cross-linked chitosan electrospun fiber mats
Publisher: Elsevier BV
Date: 12-2012
Electrosprayed poly(vinylidene fluoride) microparticles for tissue engineering applications
Publisher: Royal Society of Chemistry (RSC)
Date: 2014
DOI: 10.1039/C4RA04581E
Abstract: Poly(vinylidene fluoride) microparticles with diameters between 0.80 and 5.50 μm were produced. Cell viability shows their suitability for tissue engineering.
Effect of the microsctructure and lithium-ion content in poly[(vinylidene fluoride)-co-trifluoroethylene]/lithium perchlorate trihydrate composite membranes for battery applications
Publisher: Elsevier BV
Date: 06-2012
Determination of the parameters affecting electrospun chitosan fiber size distribution and morphology
Publisher: Elsevier BV
Date: 2012
Influence of Processing Conditions on Polymorphism and Nanofiber Morphology of Electroactive Poly(vinylidene fluoride) Electrospun Membranes
Publisher: Informa UK Limited
Date: 14-09-2010
Mechanical fatigue performance of PCL‐chondroprogenitor constructs after cell culture under bioreactor mechanical stimulus
Publisher: Wiley
Date: 12-03-2015
DOI: 10.1002/JBM.B.33386
Abstract: In tissue engineering of cartilage, polymeric scaffolds are implanted in the damaged tissue and subjected to repeated compression loading cycles. The possibility of failure due to mechanical fatigue has not been properly addressed in these scaffolds. Nevertheless, the macroporous scaffold is susceptible to failure after repeated loading-unloading cycles. This is related to inherent discontinuities in the material due to the micropore structure of the macro-pore walls that act as stress concentration points. In this work, chondrogenic precursor cells have been seeded in poly-ε-caprolactone (PCL) scaffolds with fibrin and some were submitted to free swelling culture and others to cyclic loading in a bioreactor. After cell culture, all the s les were analyzed for fatigue behavior under repeated loading-unloading cycles. Moreover, some components of the extracellular matrix (ECM) were identified. No differences were observed between s les undergoing free swelling or bioreactor loading conditions, neither respect to matrix components nor to mechanical performance to fatigue. The ECM did not achieve the desired preponderance of collagen type II over collagen type I which is considered the main characteristic of hyaline cartilage ECM. However, prediction in PCL with ECM constructs was possible up to 600 cycles, an enhanced performance when compared to previous works. PCL after cell culture presents an improved fatigue resistance, despite the fact that the measured elastic modulus at the first cycle was similar to PCL with poly(vinyl alcohol) s les. This finding suggests that fatigue analysis in tissue engineering constructs can provide additional information missed with traditional mechanical measurements.
Electrospun silk-elastin-like fibre mats for tissue engineering applications
Publisher: IOP Publishing
Date: 28-11-2013
DOI: 10.1088/1748-6041/8/6/065009
Abstract: Protein-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 are limitless and far superior to natural or synthetic materials, as the complexity of the structural design can be fully customized. In this work, we report the electrospinning of two new genetically engineered silk-elastin-like proteins (SELPs) consisting of alternate silk- and elastin-like blocks. Electrospinning was performed with formic acid and aqueous solutions at different concentrations without addition of further agents. The size and morphology of the electrospun structures was characterized by scanning electron microscopy showing its dependence on the concentration and solvent used. Treatment with methanol-saturated air was employed to stabilize the structure and promote water insolubility through a time-dependent conversion of random coils into β-sheets (FTIR). The resultant methanol-treated electrospun mats were characterized for swelling degree (570-720%), water vapour transmission rate (1083 g/m(2)/day) and mechanical properties (modulus of elasticity ∼126 MPa). Furthermore, the methanol-treated SELP fibre mats showed no cytotoxicity and were able to support adhesion and proliferation of normal human skin fibroblasts. Adhesion was characterized by a filopodia-mediated mechanism. These results demonstrate that SELP fibre mats can provide promising solutions for the development of novel biomaterials suitable for tissue engineering applications.
α to β Phase Transformation and Microestructural Changes of PVDF Films Induced by Uniaxial Stretch
Publisher: Informa UK Limited
Date: 08-05-2009
Effect of the mechanical stretching on the ferroelectric properties of a (VDF/TrFE) (75/25) copolymer film
Publisher: Elsevier BV
Date: 2004
Corrigendum to “Influence of oxygen plasma treatment parameters on poly(vinylidene fluoride) electrospun fiber mats wettability” [Prog. Org. Coat. 85 (2015) 151–158]
Publisher: Elsevier BV
Date: 09-2015
Local variation of the dielectric properties of poly(vinylidene fluoride) during the α- to β-phase transformation
Publisher: Elsevier BV
Date: 2009
Thermal degradation of Pb(Zr0.53Ti0.47 )O3/poly(vinylidene fluoride) composites as a function of ceramic grain size and concentration
Publisher: Springer Science and Business Media LLC
Date: 08-02-2013
Effect of filler size and concentration on the structure and properties of poly(vinylidene fluoride)/BaTiO3 nanocomposites
Publisher: Springer Science and Business Media LLC
Date: 13-09-2011
New technique of processing highly oriented poly(vinylidene fluoride) films exclusively in the β phase
Publisher: Wiley
Date: 28-08-2007
DOI: 10.1002/POLB.21239
Poly[(vinylidene fluoride)‐co‐trifluoroethylene] Membranes Obtained by Isothermal Crystallization from Solution
Publisher: Wiley
Date: 15-06-2010
Related Organisations
Physikalisches Institut Der Julius-Maximilians-Universität Würzburg, Germany
Location: Germany
BCMaterials, Basque Center For Materials, Applications And Nanostructures
Location: Spain
Related Funding Activities
No related grants have been discovered for senentxu lanceros-mendez.