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

Waste and Recycled Materials and their Impact on the Mechanical Properties of Construction Composite Materials

In a world increasingly fixated on the demands of sustainable development, too much attention has been focused on the widely used building materials, mainly on those tools and strategies for their reuse and those characteristics for considering them as environmental-friendly materials. Among the strategies are the following: (a) increased reliability on waste and recycled materials—such action will have to incorporate the substitution of recycled for virgin materials; (b) improved durability through reduction of materials needed for their replacement; and (c) improved mechanical properties, which reduces the use of raw materials. Extensive research and development activities in recycling composite materials have been conducted, and various technologies have been developed: (a) mechanical recycling, (b) thermal recycling, and (c) chemical recycling. However, gamma radiation is an innovative and clean technology, alternative to conventional recycling procedures. Gamma irradiation has proved to be an adequate tool for modifications of the physicochemical properties of polymers, through different effects: (a) scission, branching as well as cross-linking of polymer chains and (b) oxidative degradation. Moreover, the reuse and recycling of waste materials and the use of gamma radiation are useful tools for improving the mechanical properties of concrete. In this chapter, we show results of the effects of gamma irradiation on the physicochemical properties of waste and recycled materials and their reuse to enhance the properties of construction composite materials

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

Effects of the Addition of Ortho

The synthetic tetrapyrrole macrocycles, such as porphyrins (H2P) and phthalocyanines (H2Pc), exhibit interesting physicochemical properties suitable to be used in modern technology. For many applications, those species should be trapped or fixed inside graphite, hydrotalcites, silica, TiO2, or polymers. Methodologies for the optimization of the properties of porphyrins, trapped or fixed inside polymers, have been barely developed. Our research works in the development of methodologies for the optimization of incorporation and display of properties of tetrapyrrole macrocycles inside inorganic, polymeric, or hybrid networks. This paper shows some results about the effect of the spatial disposition of the amine (–NH2) groups attached on the periphery of substituted tetraphenylporphyrins, on the Nylon 66 structure and on the display of the physicochemical properties of the trapped macrocycles. Nylon 66 was synthesized from adipoyl chloride and hexamethylenediamine in presence of tetraphenylporphyrins substituted with –NH2 groups localized at the ortho- or para-positions of the phenyls. Cobalt complexes formation was used to quantify the amount of porphyrins in the polymer fibers. Characterization results show that the spatial position of amine groups of the porphyrins has important structural and textural effect on the Nylon 66 fibers and on the fluorescence of the porphyrins integrated into the fibers

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