Engenharia de Materiais (UACSA)
URI permanente desta comunidadehttps://arandu.ufrpe.br/handle/123456789/2913
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APP - Artigo Publicado em Periódico
TAE - Trabalho Apresentado em Evento
TCC - Trabalho de Conclusão de Curso
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Resultados da Pesquisa
Item Síntese e caracterização de um nanocompósito de grafite magnético para adsorção dos corantes Reactive Black 5 (RB5) e Azul de Metileno (AM)(2019-12-13) Damasceno, Bárbara Souza; Araújo, Ana Cláudia Vaz de; http://lattes.cnpq.br/6861890992609511; http://lattes.cnpq.br/6533105269743189Magnetic graphite nanocomposite (NGM) based on magnetic nanoparticles (NPs) and graphite nanoplatelets has been synthesized by a novel hydrothermal synthesis route. NGM and its precursors were characterized by X-ray diffraction (XRD) and infrared spectroscopy (FTIR). The nanomaterial discoloration efficiency (%Ads) using reactive black 5 (RB5) and methylene blue (AM) textile dyes in aqueous solution as target pollutant were evaluated. The influence of adsorptive parameters on effluent discoloration efficiency responses was evaluated from a 23 factorial design and the response surface analysis of central rotational composite design. Adsorption parameters evaluated include: adsorbent mass, adsorbate concentration and agitation speed. It was observed that the parameters agitation speed (rpm) and concentration of adsorbate (mg L-1) are the factors more significant than any other combination and it is highly indicated that they should be parameterized in combination. NGM statistical results showed %Ads ~98% in the RB5 removal, extremely high adsorption velocity, since it reached the adsorption equilibrium within 10 minutes of contact with the adsorbate and it presented 99% adjustment for pseudo first and second order kinetics, besides it presented a maximum adsorptive capacity of ~93 mg g-1 for the adjustment of Langmuir model, predominant in this system. The %Ads of AM onto NPs and graphite was ~59% and 100%, respectively. The study shows that NGM can be magnetically separated from the aqueous solution without introduce any byproduct during adsorption and presented favorable adsorptive properties, which makes evident its applicability of use as environmental remediator. The application of this synthetic rout becomes of technological interest when, besides being unprecedented and low cost, NGM adsorptive properties are attractive to effectively discolor wastewater.Item Resistência mecânica e térmica de compósitos reticulados de PVA/óxido de grafeno(2019-12-19) Silva, Felipe de Andrade Oliveira; Ghislandi, Marcos Gomes; http://lattes.cnpq.br/3409757365313853; http://lattes.cnpq.br/0379100954556428PVA composite films with citric acid and graphene oxide were synthesized via drop casting and crosslinked by heat treatment at 140° C for two hours. The influence of loads on mechanical, thermal and optical properties were characterized by tensile tests, thermogravimetry. and UV / VIS spectroscopy. The combined use of citric acid and graphene oxide proved to be very effective in promoting an increase in mechanical strength from 11.3 ± 1.4 MPa (pure PVA) to 37.1 ± 2.1 MPa (heat treated sample and 5% citric acid and 0.5% graphene oxide). However, there was a reduction in the maximum deformation from 333.0 ± 80.8% (pure PVA) to 84 ± 14%. The highest values obtained represent a 228% increase in mechanical strength and a 56% reduction in maximum deformation. The thermal stability of the films was analyzed by thermogravimetry; The addition of the fillers together with the heat treatment resulted in an increase in the degradation temperature from 269 ° C (pure PVA) to 325 ° C for the sample with 5% citric acid and 0.5 % graphene oxide. Optical properties were investigated by UV / VIS spectroscopy where yellowing due to heat treatment represented by a reduction in transmittance of 300-450 nm was observed. Keywords: Composites. Graphene. Cross-linking