Synthesis and Characterization of Reduced Graphene Oxide/ Polyaniline/Au Nanoparticles Hybrid Material for Energy Applications

In this work, synthesis and characterization of reduced graphene oxide/polyaniline/Au nanoparticles (GO/PANI/NpAu) as a hybrid capacitor are presented. Graphite oxide (GO) was synthesized by a modified Hummer’s method. Polyaniline was synthesized by chemical polymerization, and Au nanoparticles (NpAu) were added afterward. Fabrication of the electrodes consisted on the hybrid materials being deposited on carbon cloth electrodes. The chemical and structural properties of the electrode were characterized by high-resolution scanning electron microscopy (HRSEM), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (X-R), and Raman spectroscopy; the results confirm the graphene reduction, the covalent functionalization, and formation of nanocomposites and also show the polyaniline grafted graphene. The performance and evaluation of the electrodes based on grapheme oxide (GO), polyaniline (PANI), GO-PANI, and GO/PANI/NpAu nanocomposites over carbon cloth, stainless steel, and copper have been obtained in 1 M H2SO4 solution, using electrochemical techniques namely: cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). They showed that GO/PANI/NpAu gave higher specific capacitance (SC) and energy values than PANI, and GO/PANI, in the order of 160 F/g. The present study introduces new hybrid material for energy applications, from the evaluation of their electrical contributions

Hydrophobic Coatings for Corrosion Control of Aluminum Heat Exchangers

The production of thin films (nanocoatings) is a technological field with many applications to elaborate materials with new properties to be used as corrosion protection of traditional metals. Hydrophobicity is an example of such properties. In this chapter, an example of two hydrophobic corrosion coatings for possible use over aluminum heat exchanger geothermal power plants is discussed. Material substrate preparation, synthesis of hydrophobic sol‐gel nanocoating, characterization, and electrochemical evaluation as a function of time of immersion, which are compared to another commercial fluorinated compound, are presented. Good corrosion protection was found for both hydrophobic coatings for possible application in geothermal heat exchangers

Use of Silica Tubes as Nanocontainers for Corrosion Inhibitor Storage

A new alkyd paint anticorrosion smart coating was developed by using silica nanoparticles as corrosion inhibitor nanocontainers. Silica particles were mixed with the paint at different concentrations to study their performance and ensure their free transportation to the damaged metal. The filling up of silica particles was done preparing three solutions: distilled water, acetone, and a mixture of both, with Fe(NO3)3 and silica particles immersed in each of the solutions to adsorb the inhibitor. Acetone solution was the best alternative determined by weight gain analysis made with the inhibitor adsorbed in silica nanocontainers. Steel samples were painted with inhibitor silica nanocontainer coatings and immersed in an aqueous solution of 3% sodium chloride. Polarization curves and electrochemical noise techniques were used to evaluate the corrosion inhibitor system behavior. Good performance was obtained in comparison with samples without inhibitor nanocontainer coatin

Preparación y caracterización del complejo polianilina-fluconazol, como pigmento en un recubrimiento anticorrosivo

Se preparó una película protectora del proceso de corrosión del acero al carbono en medio neutro, utilizando la polianilina en su forma emeraldina base (PANIB) como matriz para dispersar un inhibidor (fluconazol). Para comprender el reconocimiento molecular en la formación de este complejo, se modeló computacionalmente la interacción de la emeraldina base con el fluconazol a partir de estudios de acoplamiento (docking). Después de la caracterización de los materiales mediante el modelo mencionado y técnicas como FTIR y DRX, se realizaron pruebas de Espectroscopia de Impedancia Electroquímica para evaluar la conducta protectora del complejo polianilina base-fluconazol (PANIB-F). Los resultados del modelo indicaron una débil interacción entre PANIB y el fluconazol, sin embargo, para efectos de protección del metal esto parece ser favorable.A protective film for mild Steel in neutral solution was prepared using polyaniline in its emeraldina base form (PANIB) as a matrix, in which, expired fluconazole as inhibitor was dispersed. In order to investigate the molecular recognition underlying this phenomenon (the formation of the complex), we developed a computational model for the interaction of the emeraldine base with fluconazole by docking analysis. The materials characterization was performed using FTIR and XRD techniques, and the anticorrosion behavior of the PANIB-F complex was studied at room temperature using electrochemical impedance spectroscopy. The docking model results indicated a weak interaction between PANI-B and fluconazole; however, for the metal protection purposes those results were favorable

El registro arqueometalúrgico como herramienta para conservar la información del patrimonio arquitectónico en Málaga, España

This work approaches views on the preservation of industrial housing heritage in Malaga, Spain, and the pressure caused by its recent urban renovation. The aims of the research include geographic space analysis and assessing how archaeological recording and archaeometry, specifically archaeometallurgy, can contribute to the preservation of information about structures and materials that continuously disappear from urban contexts. The results constitute an initial beginning to expand a comparative archaeological database for the city. The ideas and procedures presented here are expected to provide some guidance for generating further research from urban, architectural, archaeological, and geographical perspectives.Este trabajo aborda visiones sobre la conservación del patrimonio industrial de la vivienda en Málaga, España, y la presión provocada por su renovación urbana. Los objetivos incluyen el análisis del espacio geográfico y evaluar cómo el registro arqueológico y la arqueometría, específicamente la arqueometalurgia, pueden contribuir a la preservación de información sobre estructuras y materiales que desaparecen de los contextos urbanos. Los resultados constituyen un comienzo para elaborar una base de datos arqueológicos comparativos para la ciudad. Se espera que las ideas y los procedimientos brinden una guía para generar más investigaciones desde perspectivas urbanas, arquitectónicas, arqueológicas y geográficas

Adsorption of Fe(NO) onto Activated Nylon-6,6 as a Container and a Possible “” Corrosion Inhibitor-containing System

Nylon-6,6 exhibits chemical, thermal and mechanical properties which include resistance to chemical attack, electrical insulating properties and degradation resistance. As a possible container, it can be used to manufacture a new family of active hybrid materials, coatings and corrosion inhibitor-containing systems. The release of encapsulated corrosion inhibitors is triggered by the corrosion process itself, which prevents the spontaneous leakage of such inhibitor and provides a quick response to changes in the service environment. With this in mind, nylon-6,6 pellets were activated using either γ-irradiation or chemical attack in alkaline solution. Better pore formation was achieved employing the latter method, with such pores being filled with adsorbed ferric nitrates. Electrochemical tests were undertaken to demonstrate the performance of the “ smart ” nature of the corrosion inhibitor system formed

Nylon/Graphene Oxide Electrospun Composite Coating

Graphite oxide is obtained by treating graphite with strong oxidizers. The bulk material disperses in basic solutions yielding graphene oxide. Starting from exfoliated graphite, different treatments were tested to obtain the best graphite oxide conditions, including calcination for two hours at 700°C and ultrasonic agitation in acidic, basic, or peroxide solutions. Bulk particles floating in the solution were filtered, rinsed, and dried. The graphene oxide obtained was characterized under SEM and FTIR techniques. On the other hand, nylon 6-6 has excellent mechanical resistance due to the mutual attraction of its long chains. To take advantage of the properties of both materials, they were combined as a hybrid material. Electrochemical cells were prepared using porous silica as supporting electrode of the electrospun nylon/graphene oxide films for electrochemical testing. Polarization curves were performed to determine the oxidation/reduction potentials under different acidic, alkaline, and peroxide solutions. The oxidation condition was obtained in KOH and the reduction in H2SO4 solutions. Potentiostatic oxidation and reduction curves were applied to further oxidize carbon species and then reduced them, forming the nylon 6-6/functionalized graphene oxide composite coating. Electrochemical impedance measurements were performed to evaluate the coating electrochemical resistance and compared to the silica or nylon samples