TCC - Engenharia de Materiais (UACSA)
URI permanente para esta coleçãohttps://arandu.ufrpe.br/handle/123456789/2914
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Resultados da Pesquisa
Item Análise do processo adsortivo de corantes industriais por nanopartículas magnéticas de magnetita (Fe3O4)(2019-07-08) Cabral, Ariane Nathália de Siqueira Souza; Araújo, Ana Cláudia Vaz de; http://lattes.cnpq.br/6861890992609511; http://lattes.cnpq.br/3246406733304902Environmental degradation is an inevitable factor that accompanies the development of the population and unfortunately this has reached water systems, rivers and water sources. Among the agents that contribute to the contamination and degradation are the dyes from the textile and food industries that are discarded throughout the production processes. There are several methods being developed to eliminate the effluent dyes in rivers and springs, among which is the adsorption process. The magnetic nanoparticles of magnetite (Fe3O4) have been previously tested in the adsorption of dye residues from the textile and food industries. In this context, the objective of this work was to study the efficiency of magnetic nanoparticles of magnetite (NPs) in the adsorption process of some dyes present in industrial textile effluents, such as dyes, methyl orange (MEL) and methylene blue (AM) . A factorial design 2³ was established obtaining as factors studied time, pH and temperature, and for these factors its levels were analyzed. Analyzes were made for systems under ultrasound and under magnetic stirring, and for this, significant results were obtained for the two dyes. According to the results obtained for the ALM / NPs, factors such as time and pH with greater significance. It was observed that the most successful tests for adsorption were the tests 02 (11,362) and 06 (10,057), for the systems under ultrasound and under magnetic stirring, respectively. For the AM / NPs it was significant only the factor, time. The most favorable tests for the dye adsorption system were 04 (19,144) and 06 (21,457), for systems under ultrasound and under magnetic stirring, respectively.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-linkingItem Influência da corrente e taxa de alimentação na resistência à corrosão de revestimento à base da liga INCONEL 625 depositada por PTA-P(2019-12-10) Soares, Breno Luiz Santos; Santos, Aureliano Xavier dos; http://lattes.cnpq.br/0810494477757052Nowadays, the oil exploration process is still greatly affected by pipeline failures, which delay the production schedule, creates high maintenance costs, and creates risks to the environment and health. Thus, the search for less costly alternatives to minimize these impacts is constant, especially against failures due to corrosion. One of these is the use of materials that have high mechanical and anticorrosive properties in the form of coatings, which could be deposited by welding. The objective of this study was to evaluate the effects of the welding current and feed rate on the corrosion resistance of coatings based on the Inconel 625 alloy, deposited by PTAP process in API 5L X70 steel. The parameters were optimized using the factorial experimental design and the results analyzed by the Response Surface Methodology (RSM). Three deposits with ½ overlap were performed by PTA-P welding process, followed by an analysis of the dilution, iron content and corrosion resistance by electrochemical measurements. The coatings obtained with lower welding current and feed rate values showed better anti-corrosion properties.Item Síntese de nanomateriais de grafeno para utilização em nanocompósitos poliméricos(2019-07-11) Nogueira, Nathália Maria Barbosa; Ghislandi, Marcos Gomes; http://lattes.cnpq.br/3409757365313853; http://lattes.cnpq.br/3264027755950807Because of its unprecedented physical and chemical properties, graphene has attracted the attention of researchers searching to produce composite materials with unique properties. In this way, it has been studied the incorporation of graphene oxide loads into polymers and analyzed their influence on the mechanical, electrical and thermal behavior of the resulting composites. In this work, we present the preparation and the influence of the incorporation of graphene oxide (GO) on polyvinyl alcohol (PVOH). The mechanical reinforcement, by the incorporation of 0.5 wt%, 0.1 wt% and 1 wt% of graphene oxide into the polymer matrix, was estimated. The strategy involved the production of graphite oxide from graphite, using the modified Hummers method. The method was carried out by the addition of sulfuric acid (H2SO4), potassium permanganate (KMnO4) and hydrogen peroxide (H2O2), followed by the exfoliation of graphite oxide into sheets of graphene oxide by the use of ultrasound, and finally the preparation of the GO / PVOH nanocomposites by a simple solution mixing method. The synthesized materials were characterized by X-ray diffraction, Raman spectroscopy, and gravimetry. The analysis of the GO / PVOH films were carried out via tensile and UV-vis tests. Gravimetry showed that the solution of graphite oxide synthesized had a homogeneous concentration. X-ray diffraction (XRD) showed that the oxidative process of graphite precursor into graphite oxide was efficient. The stress-strain analysis confirmed the increase in mechanical strength of the polymeric film with the incorporation of graphene oxide load, while for the strain it was not possible to obtain conclusive data. The optical analysis showed a whitening of the film during the tensile test, indicating an alignment of the polymer chains and crystallization of the films. The UV-vis spectra showed that the pure PVOH film exhibited a high transparency, however, for the films with 0.1wt%, 0.5wt% and 1.0wt% GO this transparency decreased considerably.Item Influência da tensão, velocidade de alimentação e DBCP na resistência à corrosão de revestimentos à base da liga inconel 625 depositada por MIG(2019-07-09) Lima, Igor Jaloto de; Santos, Aureliano Xavier dos; http://lattes.cnpq.br/0810494477757052Annually, high investments are made in the maintenance of pipelines used in the oil industry around the globe. Thus, solutions are sought that combine low cost, reproducibility and properties that are consistent, mainly against corrosion. One of these is the use of materials that have high mechanical and anticorrosive properties in the form of coatings, which could be deposited by welding. The objective of this study was to evaluate the effects of different welding parameters on the corrosion resistance of coatings based on the Inconel 625 alloy, deposited by MIG process in API 5L X70 steel. The parameters were optimized using the factorial experimental design and the results analyzed by the Response Surface Methodology (RSM). Three deposits with ½ overlap were performed by MIG welding process, followed by a cross section cut in the samples for analysis of the dilution, iron content and corrosion resistance by linear potentiodynamic polarization (PPL) through corrosion potential (Ecorr), corrosion current (Icorr) and polarization resistance (Rp). The coatings obtained presented values of the dilution ranging from 5.8% to 15.01%. The coating that presented lower dilution value, also was the one with lower Icorr and Fe, besides higher Rp and Ecorr, thus, greater corrosion resistance.