Open Access
Multifunctional protective PVC-ZnO nanocomposite coatings deposited on aluminum alloys by electrospinning
(MDPI, 2019) Iribarren Zabalegui, Álvaro; Rivero Fuente, Pedro J.; Berlanga Labari, Carlos; Larumbe Abuin, Silvia; Miguel, Adrián; Rodríguez Trías, Rafael; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, PRO-UPNA 18 (6107)
This paper reports the use of the electrospinning technique for the synthesis of nanocomposite micro/nanofibers by combining a polymeric precursor with hydrophobic behavior like polyvinyl chloride (PVC) with nanoparticles of a corrosion inhibitor like ZnO. These electrospun fibers were deposited on substrates of the aluminum alloy 6061T6 until forming a coating around 100 m. The effect of varying the different electrospinning deposition parameters (mostly applied voltage and flow-rate) was exhaustively analyzed in order to optimize the coating properties. Several microscopy and analysis techniques have been employed, including optical microscopy (OM), field emission scanning electron microscopy (FE-SEM), atomic force microscopy (AFM), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Water contact angle (WCA) measurements have been carried out in order to corroborate the coating hydrophobicity. Finally, their corrosion behavior has been evaluated by electrochemical tests (Tafel curves and pitting potential measurements), showing a relevant improvement in the resultant corrosion resistance of the coated aluminum alloys.
Open Access
Visible light activation of gold nanoparticles embedded into titanium dioxide surface in electrospun polymeric coatings
(MDPI, 2024) Sandúa Fernández, Xabier; Rivero Fuente, Pedro J.; Calvopiña, Jonathan; Rodríguez Trías, Rafael; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
This work reports the development of a functional photocatalytic coating based on a combination of polymeric electrospun fibres and nanoparticles that is intended to be activated in the visible light range. In this sense, the resulting fibres can act as an effective matrix for the incorporation of titanium dioxide (TiO2) particles, which are covered by gold nanoparticles (AuNPs), in the outer surface of the metal oxide precursor. In the first step of the process, the optical properties of the nanoparticles were determined by UV-Vis spectroscopy. The extension of the visible absorption can be associated to the localized surface plasmon resonance (LSPR) of the metallic AuNPs. In addition, the resultant particle size distribution and average particle diameter was evaluated by dynamic light scattering (DLS) measurements. Furthermore, the phase composition and porosity of the functional particle powder were analysed by an XRD and N2 adsorption test. In the second step, these synthesized particles have been successfully immobilized into a PAA + β-CD electrospun fibre matrix by using the two different deposition methods of dip-coating and solution-casting, respectively. The morphological characterization of the samples was implemented by means of scanning electron microscopy (SEM), showing uniform and homogeneous, free-beaded fibres with a random distribution of the synthesized particles deposited onto the electrospun fibres. Then, the functional coatings were removed from the substrate, and a thermogravimetric (TGA) analysis was carried out for each sample in order to obtain the precursor mass immobilized in the coating. Once the overall mass of precursor was obtained, the percentage of TiO2 particles and AuNPs in the precursor was calculated by using inductively coupled plasma atomic emission spectrometry (ICP-AES). Finally, the photocatalytic activity of both functional solution and electrospun coatings were evaluated in terms of a gradual degradation of rhodamine B (RhB) dye after continuous exposition to a visible-light lamp.
Open Access
Icephobic and anticorrosion coatings deposited by electrospinning on aluminum alloys for aerospace applications
(MDPI, 2021) Vicente Gómara, Adrián; Rivero Fuente, Pedro J.; García, Paloma; Mora, Julio; Carreño, Francisco; Rodríguez Trías, Rafael; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería
Anti-icing or passive strategies have undergone a remarkable growth in importance as a complement for the de-icing approaches or active methods. As a result, many efforts for developing icephobic surfaces have been mostly dedicated to apply superhydrophobic coatings. Recently, a different type of ice-repellent structure based on slippery liquid-infused porous surfaces (SLIPS) has attracted increasing attention for being a simple and effective passive ice protection in a wide range of application areas, especially for the prevention of ice formation on aircrafts. In this work, the electrospinning technique has been used for the deposition of PVDF-HFP coatings on samples of the aeronautical alloy AA7075 by using a thickness control system based on the identification of the proper combination of process parameters such as the flow rate and applied voltage. In addition, the influence of the experimental conditions on the nanofiber properties is evaluated in terms of surface morphology, wettability, corrosion resistance, and optical transmittance. The experimental results showed an improvement in the micro/nanoscale structure, which optimizes the superhydro-phobic and anticorrosive behavior due to the air trapped inside the nanotextured surface. In addi-tion, once the best coating was selected, centrifugal ice adhesion tests (CAT) were carried out for two types of icing conditions (glaze and rime) simulated in an ice wind tunnel (IWT) on both as-deposited and liquid-infused coatings (SLIPs). The liquid-infused coatings showed a low water adhesion (low contact angle hysteresis) and low ice adhesion strength, reducing the ice adhesion four times with respect to PTFE (a well-known low-ice-adhesion material used as a reference).
Open Access
Cátedra Industria 4.0: una herramienta clave en la formación continua para estudiantes de grado en ingeniería
(Dykinson, 2020) Rivero Fuente, Pedro J.; Rodríguez Pérez, Antonio; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
En el año 2017 nace la Cátedra Industria 4.0 entre el Colegio de Graduados en Ingeniería de Navarra rama industrial (CITI-Navarra) y la Universidad Pública de Navarra (UPNA), siendo su principal objetivo el establecer un marco de colaboración científico-tecnológica entre ambas entidades. Desde su puesta en funcionamiento, la Cátedra Industria 4.0 ha llevado a cabo la realización conjunta de actividades de Investigación y Docencia que han despertado un gran interés en los alumnos (últimos cursos de Grado) tales como la realización de Trabajos Fin de Grado (TFG) con la concesión de un Premio al mejor TFG dentro de los ámbitos de interés científico-tecnológico tales como la Fabricación Avanzada, Diseño Industrial, Big Data, Automatización, Robótica y Eficiencia Energética. Por último, otro de los puntos clave de esta Cátedra ha sido la formación educativa continua con la celebración de Jornadas Técnicas. Fruto de ello, se ha realizado el "Curso Internacional de Energías Renovables" en colaboración con la Universidad de Kentuchy con el principal objetivo de que los alumnos conozcan diferentes tipos de energías renovables (eólica, termosolar, fotovoltaica, biomasa, geotérmica e hidroeléctrica) y comprendan cuál es su impacto económico. Este curso resulta especialmente de interés ya que favorece el intercambio de conocimiento e ideas entre profesionales y alumnos de distintas nacionalidades.
Open Access
Modelización y estudio experimental y mediante CFD de un ventilador para alumnos de Grado en Ingeniería Mecánica y de Tecnologías Industriales
(Dykinson, 2021) Fuertes Bonel, Juan Pablo; Torres Salcedo, Alexia; Rivero Fuente, Pedro J.; Armañanzas Goñi, Javier; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
El trabajo planteado en esta comunicación tiene como principales objetivos por un lado, el conocimiento del funcionamiento un ventilador y por el otro, el empleo de softwares propios del diseño (CAD) y de la Mecánica de Fluidos (CFD). Con esto, se busca que el alumno amplíe y afiance sus conocimientos de una máquina fluidomecánica vista en el aula y también, que aprecie la importancia que tiene en ingeniería el trabajo multidisciplinar. Se ha escogido un ventilador, ya que por un lado, su modelización en CAD es más sencilla frente a otras máquinas hidráulicas, como puede ser una bomba centrífuga, y por el otro, porque dentro de las asignaturas de los distintos grados, el estudio del ventilador se realiza en menor profundidad, que el de las máquinas hidráulicas. El trabajo del alumno consta de tres partes diferenciadas: experimentación, diseño y simulación mediante CFD. En la experimentación, el objetivo es que el alumnado pueda manipular un ventilador en el laboratorio contrastando lo visto en teoría con la realidad, y que mediante una toma de datos establecida previamente, se familiarice con su funcionamiento. El siguiente paso consiste en diseñar en CAD la máquina y de esta manera, que puedan poner en práctica lo aprendido en asignaturas anteriores, en cuanto a diseño en CAD se refiere. Por último, y como complemento a las clases sobre CFD, que se imparten en la asignatura donde está programado este trabajo, se pide que el alumnado sea capaz de simular el funcionamiento del ventilador experimentado.
Open Access
Layer-by-layer assembly as a powerful nanofabrication technique for the design of antimicrobial surfaces in the textile industry
(Taylor & Francis, 2022) Rivero Fuente, Pedro J.; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
In this work, the fabrication of multilayer structures has been presented by using the layer-by-layer (LbL) nanoassembly technique with the aim to prevent the bacterial adhesion, pathogen colonization, or even contact-killing bacteria. The use of this nanofabrication technique is of great interest because the resultant thickness of the films can be perfectly controlled as a function of the electrostatic attraction between positive and negative charged compounds. In addition, this technique shows a great versatility because it can be implemented to a wide variety of substrates with any shape and composition (i.e., polymers, composites, medical devices, metallic substrates) without using any expensive equipment. In some cases, the polyelectrolytes can play a dual role for preparing multilayer antimicrobial surfaces. The first one is that most of them can be used for embedding active compounds, which can be released in a further step, while the second one, controlling the pH of the dipping cationic polyelectrolyte solutions can induce the presence of higher protonated charges in the outer surface, which 256can act as a better effective antimicrobial activity. Finally, a perspective in detail of these different approaches will be deeply analyzed against different bacterial strains.
Open Access
Hydrophobic and corrosion behavior of sol-gel hybrid coatings based on the combination of TiO2 NPs and fluorinated chains for aluminum alloys protection
(MDPI, 2018) Rivero Fuente, Pedro J.; Maeztu Redin, Juan Deyo; Berlanga Labari, Carlos; Miguel, Adrián; Rodríguez Trías, Rafael; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Ingeniería; Universidad Pública de Navarra / Nafarroako Unibertsitate Publikoa, Navarre-PRO-UPNA18-6107-FRRRIO
In this work, layers of a sol-gel hybrid matrix doped with metal oxide nanoparticles (TiO2 NPs) have been deposited on flat samples of AA6061-T6 aluminum alloy using the dip-coating technique, with the aim of obtaining coatings with better anti-corrosive and hydrophobic properties. Two different organic modified silica alkoxides, namely 3-(glycidyloxypropyl)trimethoxysilane (GPTMS) and methyltriethoxysilane (MTEOS), have been used for an adequate entrapment of the metal oxide nanoparticles. In addition, a fluorinated metal-alkoxide precursor has also been added to the hybrid matrix in order to improve the hydrophobic behavior. The experimental results corroborate that the presence of these TiO2 NPs play an important role in the development of the sol-gel hybrid coatings. The water contact angle (WCA) measurements, as well as pencil hardness tests indicate that TiO2 NPs make a considerable increase in the resultant hydrophobicity possible, with better mechanical properties of the coatings. The coating thickness has been measured by cross-section scanning electron microscopy (SEM). In addition, a glow discharge optical emission spectroscopy (GD-OES) analysis has been carried out in order to corroborate the adequate entrapment of the TiO2 NPs into the sol-gel coatings. Finally, potentiodynamic polarization tests and electrochemical impedance spectroscopy (EIS) have been performed in order to evaluate the corrosion resistance of the coatings. All the results provide insights into the efficacy of the developed sol-gel hybrid coatings for anticorrosive purposes with good mechanical properties.
Open Access
An antibacterial surface coating composed of PAH/SiO2 nanostructurated films by layer by layer
(Wiley, 2010) Urrutia Azcona, Aitor; Rivero Fuente, Pedro J.; Ruete Ibarrola, Leyre; Goicoechea Fernández, Javier; Fernández Valdivielso, Carlos; Arregui San Martín, Francisco Javier; Matías Maestro, Ignacio; Ingeniería; Ingeniaritza; Ingeniería Eléctrica, Electrónica y de Comunicación; Ingeniaritza Elektrikoa, Elektronikoa eta Telekomunikazio Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Institute of Smart Cities - ISC
In this work we propose a novel antibacterial coating composed of SiO2 and the polymer Poly(allylamine hydrochloride) (PAH). The coating was fabricated by the technique Layer-by-Layer (LbL). This technique has already been used in previous works, and it has the advantage that it allows to control the construction of nanosized and well organized multilayer films. Here, the new nanotexturized LbL SiO2 surface acts as antibacterial agent. The fabricated coatings have been tested in bacterial cultures of genus Lactobacillus to observe their antibacterial properties. It has been demonstrated these PAH/SiO2 coating films have a very good antimicrobial behaviour against this type of bacteria.
Open Access
Comparative study of electrospun polydimethylsiloxane fibers as a substitute for fluorine-based polymeric coatings for hydrophobic and icephobic applications
(MDPI, 2024-11-30) Vicente Gómara, Adrián; Rivero Fuente, Pedro J.; Santos, Cleis; Rehfeld, Nadine; Rodríguez Trías, Rafael; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2; Universidad Pública de Navarra / Nafarroako Univertsitate Publikoa, PJUPNA1929
The development of superhydrophobic, waterproof, and breathable membranes, as well as icephobic surfaces, has attracted growing interest. Fluorinated polymers like PTFE or PVDF are highly effective, and previous research by the authors has shown that combining these polymers with electrospinning-induced roughness enhances their hydro- and ice-phobicity. The infusion of these electrospun mats with lubricant oil further improves their icephobic properties, achieving a slippery liquid-infused porous surface (SLIPS). However, their environmental impact has motivated the search for fluorine-free alternatives. This study explores polydimethylsiloxane (PDMS) as an ideal candidate because of its intrinsic properties, such as low surface energy and high flexibility, even at very low temperatures. While some published results have considered this polymer for icephobic applications, in this work, the electrospinning technique has been used for the first time for the fabrication of 95% pure PDMS fibers to obtain hydrophobic porous coatings as well as breathable and waterproof membranes. Moreover, the properties of PDMS made it difficult to process, but these limitations were overcome by adding a very small amount of polyethylene oxide (PEO) followed by a heat treatment process that provides a mat of uniform fibers. The experimental results for the PDMS porous coating confirm a hydrophobic behavior with a water contact angle (WCA) ≈ 118° and roll-off angle (αroll-off) ≈ 55°. In addition, the permeability properties of the fibrous PDMS membrane show a high transmission rate (WVD) ≈ 51.58 g∙m−2∙d−1, providing breathability and waterproofing. Finally, an ice adhesion centrifuge test showed a low ice adhesion value of 46 kPa. These results highlight the potential of PDMS for effective icephobic and waterproof applications.
Open Access
Corrosion of cast aluminum alloys: a review
(MDPI, 2020-10-16) Berlanga Labari, Carlos; Biezma Moraleda, María Victoria; Rivero Fuente, Pedro J.; Ingeniería; Ingeniaritza; Institute for Advanced Materials and Mathematics - INAMAT2
Research on corrosion resistance of cast aluminum alloys is reviewed in this article. The effect of the main microstructural features of cast aluminum alloys such as secondary dendrite arm spacing (SDAS), eutectic silicon morphology, grain size, macrosegregation, microsegregation, and intermetallic compounds is discussed. Moreover, the corrosion resistance of cast aluminum alloys obtained by modern manufacturing processes such as semi-solid and additive manufacturing are analyzed. Finally, the protective effects provided by different coatings on the aluminum cast alloys—such as anodized, plasma electrolytic oxidation (PEO), and laser—is reviewed. Some conclusions and future guidelines for future works are proposed.