Luciano Nascimento

STUDY OF PHYSICAL AND CHEMICAL CHARACTERIZATION OF NANOCOMPOSITE POLYSTYRENE / GRAPHENE OXIDE HIGH ACIDITY CAN BE APPLIED IN THIN FILMS

This paper shows a study of Nanocomposite formed by adding reduced Graphene oxide with high acidity and polystyrene. The interest and research in the material is due to the ability of these nanoparticles significantly altering the electrical and mechanical properties of the polymer, even addition of small levels. The existence of functional groups on the graphene oxide containing abundant oxygen such as; epoxy, hydroxyl and carboxylic acid, can be well dispersed in the polymer because of its good interaction with polymer chains. In this study we used the solution by dispersing method to that made the use of solvent tetrahydrofuran (THF), for purposes of obtaining a reaction with functionalization of graphene oxide / polystyrene in time of 48 hours. The analyses of physical-chemical characterizations were made diffraction X-ray (XRD), scanning electron microscopy (SEM), Infrared Spectroscopy (IRD), Thermogravimetric Analysis (TG) and Differential calorimeter by scanning (DSC). The results obtained by XRD diffraction pattern showed a strong expansion in the peak, indicating amorphization on single sheets of graphene oxide due to distorted sp3 sites CO. The morphology of the nanocomposite structure was with surface roughness, folds and rough predominant oxidation process of oxygenated functional groups. Their techniques showed the range of absorption, crystallinity degree and the mass loss. Finally, current and future possible applications of formed polystyrene nanocomposite/ graphene oxide show high acidity efficiency in the use of thin films.

Al62Cu25Fe12 and Quasicrystalline Phases and Their Influence on Oxidation

In this article, we will cover a study of the formation of icosahedral and decagonal phases two quasicrystals Al 62 Cu 25 Fe 12 and Al 65 Ni 15 Co 20 oxidation of influence in this alloy. For this purpose, research used the diffraction of X-ray, scanning electron microscopy/energy dispersive spectroscopy, differential scanning calorimetry and thermogravimetric analysis. The results displayed found aspects of morphological structural as well as the surface of the two compositions of quasicrystals, these were prepared and obtained in electric arc furnaces and induction and arc. Oxidation of Al 62 Cu 25 Fe 12 alloy, intermetallic phases presented with combinations of alloying elements and above 675 °C it was observed that the crystalline phase is stable. In icosahedral phase oxidation of aluminum forms a dense layer on the passivating outer most surface of the quasicrystal which causes depletion in both copper and iron. In Al 65 Ni 15 Co 20 nominal composition of oxygen interaction occurs on the surface of symmetry 10 times plane perpendicular vector. The formation of a thin film of aluminum oxide having well-ordered hexagonal structure and with the opposition area decagonal phase with the lateral size of approximately 35A. DOI: http://dx.doi.org/10.17807/orbital.v9i1.872

CHARACTERIZATION OF AMORPHOUS ALLOY Co87Nb46B15

This paper presents a discussion of the processing and characterization of alloy Co87Nb46B15 produced by rapid solidification, in which characterization techniques such as X-Ray Diffraction (XRD), scanning electron microscopy and spectroscopy Dispersion Energy (SEM / EDS) and magnetic properties were used, with the study of hysteresis curve. Several researches have been making on nanocrystalline materials, especially cobalt-base alloys, because of their thermodynamic stability, characterization and processing. Amorphous alloys have a structure of ultrafine, homogeneous grains with small crystal clusters in amorphous phase.