The development of new materials with specific functionalities for certain applications has been increasing with the advent of nanotechnology. A technique widely used for this purpose is electrospinning, because control of several parameters involved in the process can yield nanoscale fibers. In addition to the production of innovative and small-scale materials, through structural, chemical, physical, and biological modifications in the fibers produced in electrospinning, it is possible to obtain specific properties for a given application. Thus, the produced fibers can serve different purposes, such as in the areas of sensors, catalysis, and environmental and medical fields. Given this context, this article presents a review of the electrospinning technique, addressing the parameters that influence the properties of the fibers formed and some techniques used to modify them as specific treatments that can be conducted during or after electrospinning. In situ addition of nanoparticles, changes in the configuration of the metallic collector, use of alternating current, electret fibers, core/shell method, coating, electrospray-coating, plasma, reinforcing composite materials, and thermal treatments are some of the examples addressed in this work. Therefore, this work contributes to a better comprehension of some of the techniques mentioned in the literature so far.

The growing increase in emissions of ultrafine particles or nanoparticles by industries and urban centers has become worrisome due to the potential adverse health effects when inhaled. Particles in this size range have greater ease of pulmonary penetration, being able to access the bloodstream and deposit in other regions of the body. Thus, the development and optimization of equipment and processes aimed at the removal of aerosols of nanoparticles have been gaining importance in this current scenario. Among the equipment commonly used, electrostatic precipitators and filters stand out as being versatile and consolidated processes in the literature. This review explores and analyzes the theoretical bases of these two processes in the collection of such small particles in addition to providing a general overview of the development of technologies and studies on these topics.

Metal surface pre-treatment is a known process and is used to increase corrosion performance as well as improve adhesion between the substrate and the paint layer. The present paper evaluated the corrosion resistance of carbon steel before and after treatment with nanoceramic coatings. The comparison was between a pure zirconia nanoceramic compound (Bonderite NT-1), with the addition of a dispersant (polyacrylic acid) and another nanoceramic coating developed from titanium oxide. Additionally, salt spray, open circuit potential (OCP), polarization and impedance tests were performed to obtain a methodology to quantitatively assess the quality of protection. The zirconia coating presented superior characteristics than the corrosion protection. The corrosion potential of this coating was about twice as low as the others. The addition of dispersant produced no significant improvements in corrosion resistance and was similar to uncoated carbon steel, possibly due to the high concentration used.

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O Brasil é um dos maiores produtores mundiais de etanol proveniente de cana-de-açúcar. No processo de produção do biocombustível etanol vários resíduos são gerados, dentre eles destaca-se a vinhaça como o mais preocupante, devido as suas características físico-químicas e grande volume gerado. Este efluente é caracterizado altos teores de matéria orgânica, apresentando elevada demanda bioquímica de oxigênio (DBO), pH ácido e a presença de elementos como potássio e enxofre. Tais propriedades conferem a vinhaça um grande poder como poluidor ambiental. Estudos demonstram a contaminação de águas, solos, flora e fauna de mananciais. Considerando-se que o etanol é produzido empregando-se diferentes matérias primas, em inúmeros países, é possível concluir que estamos diante de um problema mundial bastante relevante, relacionado aos usos, armazenamento e descarte desse efluente. Essa revisão apresenta detalhadamente a origem, as propriedades e os impactos ambientais relacionados à vinhaça.