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Prof. Dr. Gelmires de Araujo Neves
Academic Unit of Materials Engineering, Federal University of Campina Grande, Campina Grande - PB 58430-330, Brazil

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Research Keywords & Expertise

0 development of new materials
0 Processing of ceramic materials
0 Non-metallic materials
0 Extraction and transformation of materials
0 Ceramic materials, environmental

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Journal article
Published: 26 August 2021 in Nanomaterials
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The development of alternatives for wear protection in surface engineering can be responsible for a significant decrease in energy waste as a large amount of the energy produced in the world is lost due to tribological contact. Dynamic Glancing Angle Deposition has been recently evaluated as a route to produce coatings with improved wear performance. In this technique, the substrate oscillates along with a determined range in front of the sputtering target during the growth of the film. In this study, five oscillatory ranges (0, ±5°, ±10°, ±15°, ±20°) were probed to manufacture nanostructured Cr-Al-N coatings using direct current magnetron sputtering, and their impact was investigated on the grain morphology, phase formation, chemical composition, and performance of the coatings. FEG-SEM revealed the formation of multilayer-like architecture across the grains of the coatings. The deposition rate and hardness improved, and a more than 2-fold decrease in the material loss was observed in a comparison between the stationary-deposited conventional coating and the sample produced under ±10° oscillatory range. This indicated the potential use of this technique in future surface engineering applications.

ACS Style

Pedro Renato Tavares Avila; Raíra Chefer Apolinário; Alisson Mendes Rodrigues; Jucielle Veras Fernandes; Romualdo Rodrigues Menezes; Gelmires De Araújo Neves; Haroldo Cavalcanti Pinto. On Improving Wear Resistance of Cr-Al-N Coatings Using Dynamic Glancing Angle DC Magnetron Sputtering. Nanomaterials 2021, 11, 2187 .

AMA Style

Pedro Renato Tavares Avila, Raíra Chefer Apolinário, Alisson Mendes Rodrigues, Jucielle Veras Fernandes, Romualdo Rodrigues Menezes, Gelmires De Araújo Neves, Haroldo Cavalcanti Pinto. On Improving Wear Resistance of Cr-Al-N Coatings Using Dynamic Glancing Angle DC Magnetron Sputtering. Nanomaterials. 2021; 11 (9):2187.

Chicago/Turabian Style

Pedro Renato Tavares Avila; Raíra Chefer Apolinário; Alisson Mendes Rodrigues; Jucielle Veras Fernandes; Romualdo Rodrigues Menezes; Gelmires De Araújo Neves; Haroldo Cavalcanti Pinto. 2021. "On Improving Wear Resistance of Cr-Al-N Coatings Using Dynamic Glancing Angle DC Magnetron Sputtering." Nanomaterials 11, no. 9: 2187.

Journal article
Published: 17 August 2021 in Sustainability
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Tailing incorporation into mortars has been the subject of much research in recent years. Despite this, most of these studies did not investigate the harmful effects resulting from the exposure of such mortars to an environment containing aggressive agents. This work investigated the effects of perlite tailing addition into mortars containing cement CP V-ARI MAX and hydrated lime. The raw materials were subjected to chemical characterization (X-ray fluorescence (XRF)) and mineralogical (X-ray diffraction (XRD)), while the samples immersed in 1 N NaOH solution were characterized by XRD, thermogravimetric analysis (TGA), scanning electron microscopy (SEM), and compression strength (CS). The results showed the harmful effects of incorporating perlite tailings into the mortar investigated. Such a degradation was proven by linear expansion and compressive strength experiments accomplished in the samples after the test of resistance to an alkali–silicate reaction.

ACS Style

Roberto Evaristo de Oliveira Neto; Juliana De Melo Cartaxo; Alisson Mendes Rodrigues; Gelmires De Araújo Neves; Romualdo Rodrigues Menezes; Fabiana Pereira da Costa; Sâmea Valensca Alves Barros. Durability Behavior of Mortars Containing Perlite Tailings: Alkali–Silicate Reaction Viewpoint. Sustainability 2021, 13, 9203 .

AMA Style

Roberto Evaristo de Oliveira Neto, Juliana De Melo Cartaxo, Alisson Mendes Rodrigues, Gelmires De Araújo Neves, Romualdo Rodrigues Menezes, Fabiana Pereira da Costa, Sâmea Valensca Alves Barros. Durability Behavior of Mortars Containing Perlite Tailings: Alkali–Silicate Reaction Viewpoint. Sustainability. 2021; 13 (16):9203.

Chicago/Turabian Style

Roberto Evaristo de Oliveira Neto; Juliana De Melo Cartaxo; Alisson Mendes Rodrigues; Gelmires De Araújo Neves; Romualdo Rodrigues Menezes; Fabiana Pereira da Costa; Sâmea Valensca Alves Barros. 2021. "Durability Behavior of Mortars Containing Perlite Tailings: Alkali–Silicate Reaction Viewpoint." Sustainability 13, no. 16: 9203.

Journal article
Published: 21 April 2021 in Minerals
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Natural stones (limestones, granites, and marble) from mines located in northeastern Brazil were investigated to discover their potential for use in civil construction. The natural stones were characterized by chemical analysis, X-ray diffraction, differential thermal analysis, and optical microscopy. The physical-mechanical properties (apparent density, porosity, water absorption, compressive and flexural strength, impact, and abrasion) and chemical resistance properties were also evaluated. The results of the physical-mechanical analysis indicated that the natural stones investigated have the potential to be used in different environments (interior, exterior), taking into account factors such as people’s circulation and exposure to chemical agents.

ACS Style

Fabiana Costa; Jucielle Fernandes; Luiz Melo; Alisson Rodrigues; Romualdo Menezes; Gelmires Neves. The Potential for Natural Stones from Northeastern Brazil to Be Used in Civil Construction. Minerals 2021, 11, 440 .

AMA Style

Fabiana Costa, Jucielle Fernandes, Luiz Melo, Alisson Rodrigues, Romualdo Menezes, Gelmires Neves. The Potential for Natural Stones from Northeastern Brazil to Be Used in Civil Construction. Minerals. 2021; 11 (5):440.

Chicago/Turabian Style

Fabiana Costa; Jucielle Fernandes; Luiz Melo; Alisson Rodrigues; Romualdo Menezes; Gelmires Neves. 2021. "The Potential for Natural Stones from Northeastern Brazil to Be Used in Civil Construction." Minerals 11, no. 5: 440.

Journal article
Published: 02 April 2021 in Sustainability
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The effect of acid treatment on the adsorptive capacity of a Brazilian palygorskite to remove the crystal violet (CV) and congo red (CR) dyes was investigated. The raw palygorskite was acid-treated by different HCl solutions (2, 4, and 6 mol/L). The modifications on the palygorskite structure were investigated using X-ray diffraction, X-ray fluorescence, Fourier-transform infrared spectroscopy, N2 adsorption/desorption, and thermogravimetric and differential thermal analysis. The efficiency of CV and CR adsorption was investigated, and the effect of the initial concentration, contact time, pH, and adsorbent amount was analyzed. The results revealed that CV adsorption in the acid-treated palygorskite was higher than that of the raw material. A Langmuir isotherm model was observed for the adsorption behavior of CV, while a Freundlich isotherm model was verified for the CR adsorption. A pseudo-second-order model was observed for the adsorption kinetics of both dyes. The higher CV adsorption capacity was observed at basic pH, higher than 97%, and the higher CR removal was observed at acidic pH, higher than 50%. The adsorption parameters of enthalpy (ΔH), entropy (ΔS), and Gibbs energy (ΔG) were evaluated. The adsorption process of the CV and CR dyes on the raw and acid-treated Brazilian palygorskite was predominantly endothermic and occurred spontaneously. The studied raw palygorskite has a mild-adsorption capacity to remove anionic dyes, while acid-treated samples effectively remove cationic dyes.

ACS Style

Vanderlane Silva; Maria Araújo; Alisson Rodrigues; Juliana Cartaxo; Romualdo Menezes; Gelmires Neves. Adsorption Behavior of Acid-Treated Brazilian Palygorskite for Cationic and Anionic Dyes Removal from the Water. Sustainability 2021, 13, 3954 .

AMA Style

Vanderlane Silva, Maria Araújo, Alisson Rodrigues, Juliana Cartaxo, Romualdo Menezes, Gelmires Neves. Adsorption Behavior of Acid-Treated Brazilian Palygorskite for Cationic and Anionic Dyes Removal from the Water. Sustainability. 2021; 13 (7):3954.

Chicago/Turabian Style

Vanderlane Silva; Maria Araújo; Alisson Rodrigues; Juliana Cartaxo; Romualdo Menezes; Gelmires Neves. 2021. "Adsorption Behavior of Acid-Treated Brazilian Palygorskite for Cationic and Anionic Dyes Removal from the Water." Sustainability 13, no. 7: 3954.

Journal article
Published: 01 January 2021 in Matéria (Rio de Janeiro)
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RESUMO Mulita é um material que tem recebido atenção especial devido às suas propriedades químicas, físicas e mecânicas, que estão correlacionadas com o método de síntese utilizado. O método sol-gel destaca-se frente aos outros métodos químicos devido à possibilidade de obtenção de materiais com elevado grau de pureza e baixas temperaturas de síntese. Sendo assim, este trabalho teve por objetivo a análise dos solventes água, álcool etílico, álcool isopropílico e tetrahidrofurano, na obtenção de mulita por meio da rota sol-gel. As amostras foram caracterizadas por difração de raios X (DRX), análise termogravimétrica e diferencial (TG/ATD), adsorção de nitrogênio, microscopia eletrônica de varredura (MEV) e microscopia eletrônica de transmissão (MET). Os resultados mostraram que a mulita foi sintetizada com todos os solventes, porém, o uso dos álcoois como solvente proporcionou a obtenção das amostras mais cristalinas, com as menores perdas de massa, com uma morfologia formada por agregados e partículas individualizadas.

ACS Style

Aluska Do Nascimento Simões Braga; Geysivana Kessya Garcia Carvalho; Hélio De Lucena Lira; Gelmires De Araújo Neves; Romualdo Rodrigues Menezes. Influência de diferentes solventes na síntese de mulita por sol-gel. Matéria (Rio de Janeiro) 2021, 26, 1 .

AMA Style

Aluska Do Nascimento Simões Braga, Geysivana Kessya Garcia Carvalho, Hélio De Lucena Lira, Gelmires De Araújo Neves, Romualdo Rodrigues Menezes. Influência de diferentes solventes na síntese de mulita por sol-gel. Matéria (Rio de Janeiro). 2021; 26 (2):1.

Chicago/Turabian Style

Aluska Do Nascimento Simões Braga; Geysivana Kessya Garcia Carvalho; Hélio De Lucena Lira; Gelmires De Araújo Neves; Romualdo Rodrigues Menezes. 2021. "Influência de diferentes solventes na síntese de mulita por sol-gel." Matéria (Rio de Janeiro) 26, no. 2: 1.

Journal article
Published: 01 December 2020 in Engenharia Sanitaria e Ambiental
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RESUMO Este trabalho objetivou imobilizar metais pesados presentes nos resíduos de quartzito por meio da incorporação em argamassas em substituição total ao agregado natural. Dois tipos de resíduos foram utilizados: os resíduos de fragmentação das aparas (QS) e os do pó de serragem (QP). Os resíduos foram caracterizados por fluorescência de raios X, difração de raios X e ensaios de toxidade conforme metodologia da Norma Brasileira (NBR) 10005, da NBR 10006 e do Toxicity Characteristic Leaching Procedure (TCLP) 1311. Então, foram analisadas composições de argamassas contendo cimento, cal e os resíduos (QS, QP) utilizando-se a técnica de delineamento de mistura, determinando os melhores traços, o melhor tipo de cura (imersa ou úmida) e, posteriormente, avaliando a resistência dos corpos de prova após cura. A caracterização do resíduo de quartzito revelou a presença de vários metais pesados e extratos lixiviados em contato com a água, classificando-o como resíduo de Classe I — Perigoso. Os resultados indicam que as composições determinadas foram capazes de imobilizar os metais pesados presentes nos resíduos de quartzitos, bem como resultou em argamassas com resistências mecânicas superiores a 2 MPa. Por fim, mostrou-se que essa técnica de solubilização e estabilização dos contaminantes presentes nos resíduos de quartzito é uma alternativa tecnologicamente viável e ambientalmente adequada para a destinação final desses resíduos.

ACS Style

Sâmea Valensca Alves Barros; Gerbeson Carlos Batista Dantas; Gelmires De Araújo Neves; Romualdo Rodrigues Menezes. Imobilização de metais pesados presentes nos resíduos de quartzito por meio da incorporação em argamassas com substituição total do agregado natural. Engenharia Sanitaria e Ambiental 2020, 25, 833 -845.

AMA Style

Sâmea Valensca Alves Barros, Gerbeson Carlos Batista Dantas, Gelmires De Araújo Neves, Romualdo Rodrigues Menezes. Imobilização de metais pesados presentes nos resíduos de quartzito por meio da incorporação em argamassas com substituição total do agregado natural. Engenharia Sanitaria e Ambiental. 2020; 25 (6):833-845.

Chicago/Turabian Style

Sâmea Valensca Alves Barros; Gerbeson Carlos Batista Dantas; Gelmires De Araújo Neves; Romualdo Rodrigues Menezes. 2020. "Imobilização de metais pesados presentes nos resíduos de quartzito por meio da incorporação em argamassas com substituição total do agregado natural." Engenharia Sanitaria e Ambiental 25, no. 6: 833-845.

Journal article
Published: 12 November 2020 in Sustainability
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In this study, we develop ceramic formulations based on quartzite and scheelite tailings collected from mining companies in the northeast of Brazil (Rio Grande do Norte State). New ceramic samples (27 wt% of kaolin, 29 wt% of plastic clay, 11 wt% of quartzite tailing, and 0–8 wt% scheelite tailing) were uniaxially pressed in two steps (20 MPa and 50 Mpa for 20 s); dried at 110 °C for 24 h; and sintered at 1150 °C, 1200 °C, and 1250 °C. The main mineralogical phases (mullite, quartz, calcite, and anorthite) of the sintered samples were identified using X-ray diffraction (XRD). After evaluation of the physical-mechanical properties (water absorption, linear shrinkage, apparent porosity, and flexural strength), it was observed that the incorporation of scheelite tailing by up to 8 wt% did not significantly alter the properties of samples sintered at all temperatures. Our results indicate that the new ceramics formulations developed have strong potentials in manufacturing sustainable materials such as ceramic tiles and porcelain stoneware.

ACS Style

Jucielle Fernandes; Danyelle Guedes; Fabiana Da Costa; Alisson Rodrigues; Gelmires Neves; Romualdo Menezes; Lisiane Santana. Sustainable Ceramic Materials Manufactured from Ceramic Formulations Containing Quartzite and Scheelite Tailings. Sustainability 2020, 12, 9417 .

AMA Style

Jucielle Fernandes, Danyelle Guedes, Fabiana Da Costa, Alisson Rodrigues, Gelmires Neves, Romualdo Menezes, Lisiane Santana. Sustainable Ceramic Materials Manufactured from Ceramic Formulations Containing Quartzite and Scheelite Tailings. Sustainability. 2020; 12 (22):9417.

Chicago/Turabian Style

Jucielle Fernandes; Danyelle Guedes; Fabiana Da Costa; Alisson Rodrigues; Gelmires Neves; Romualdo Menezes; Lisiane Santana. 2020. "Sustainable Ceramic Materials Manufactured from Ceramic Formulations Containing Quartzite and Scheelite Tailings." Sustainability 12, no. 22: 9417.

Review
Published: 06 November 2020 in Materials
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Chitosan, derived from chitin, is a biopolymer consisting of arbitrarily distributed β-(1-4)-linked D-glucosamine and N-acetyl-D-glucosamine that exhibits outstanding properties— biocompatibility, biodegradability, non-toxicity, antibacterial activity, the capacity to form films, and chelating of metal ions. Most of these peculiar properties are attributed to the presence of free protonable amino groups along the chitosan backbone, which also gives it solubility in acidic conditions. Moreover, this biopolymer can also be physically modified, thereby presenting a variety of forms to be developed. Consequently, this polysaccharide is used in various fields, such as tissue engineering, drug delivery systems, and cancer treatment. In this sense, this review aims to gather the state-of-the-art concerning this polysaccharide when used as a biomaterial, providing information about its characteristics, chemical modifications, and applications. We present the most relevant and new information about this polysaccharide-based biomaterial’s applications in distinct fields and also the ability of chitosan and its various derivatives to selectively permeate through the cancer cell membranes and exhibit anticancer activity, and the possibility of adding several therapeutic metal ions as a strategy to improve the therapeutic potential of this polymer.

ACS Style

Rayssa De Sousa Victor; Adillys Marcelo Da Cunha Santos; Bianca Viana De Sousa; Gelmires De Araújo Neves; Lisiane Navarro De Lima Santana; Romualdo Rodrigues Menezes. A Review on Chitosan’s Uses as Biomaterial: Tissue Engineering, Drug Delivery Systems and Cancer Treatment. Materials 2020, 13, 4995 .

AMA Style

Rayssa De Sousa Victor, Adillys Marcelo Da Cunha Santos, Bianca Viana De Sousa, Gelmires De Araújo Neves, Lisiane Navarro De Lima Santana, Romualdo Rodrigues Menezes. A Review on Chitosan’s Uses as Biomaterial: Tissue Engineering, Drug Delivery Systems and Cancer Treatment. Materials. 2020; 13 (21):4995.

Chicago/Turabian Style

Rayssa De Sousa Victor; Adillys Marcelo Da Cunha Santos; Bianca Viana De Sousa; Gelmires De Araújo Neves; Lisiane Navarro De Lima Santana; Romualdo Rodrigues Menezes. 2020. "A Review on Chitosan’s Uses as Biomaterial: Tissue Engineering, Drug Delivery Systems and Cancer Treatment." Materials 13, no. 21: 4995.

Original paper
Published: 23 October 2020 in Clean Technologies and Environmental Policy
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To increase the effectiveness of fertilizers, new controlled release nitrogen fertilizers have been developed from a mixture of urea and natural smectitic clays and organoclays with different surfactants (ionic and nonionic) encapsulated in an insoluble, biodegradable polymer film. Smectitic clays were classified according to their chemical, physical and mineralogical aspects. Mixtures of urea and natural/organoclays were pressed, and the specimens were dipped into a polymeric solution of poly-ε-caprolactone and acetone (solvent). The resulting controlled release fertilizers were analyzed by infrared spectroscopy and by scanning electron microscopy. The release of urea was evaluated by kinetic dissolution test in aqueous medium as determined by analysis on a UV–visible spectrophotometer. The results have shown that organoclays, especially those with nonionic surfactant coated with a PCL film, favored kinetic and gradual delay in the release of urea. This meets the standards established by the European Committee for Standardization, favoring, therefore, important agro-industrial advances at both national and international levels, securing sustainability in the technological sector.

ACS Style

I. A. Silva; D. S. Silva; M. U. Sousa; R. R. Menezes; H. S. Ferreira; G. A. Neves. Encapsulation of nitrogen fertilizers in mixtures with organoclays for controlled release. Clean Technologies and Environmental Policy 2020, 22, 2163 -2176.

AMA Style

I. A. Silva, D. S. Silva, M. U. Sousa, R. R. Menezes, H. S. Ferreira, G. A. Neves. Encapsulation of nitrogen fertilizers in mixtures with organoclays for controlled release. Clean Technologies and Environmental Policy. 2020; 22 (10):2163-2176.

Chicago/Turabian Style

I. A. Silva; D. S. Silva; M. U. Sousa; R. R. Menezes; H. S. Ferreira; G. A. Neves. 2020. "Encapsulation of nitrogen fertilizers in mixtures with organoclays for controlled release." Clean Technologies and Environmental Policy 22, no. 10: 2163-2176.

Journal article
Published: 09 September 2020 in Sustainability
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The inadequate discharge of effluents from different sources without prior treatment can impact the characteristics of soil and water, which reflect serious environmental problems. Advanced oxidative processes (AOP) appear as a viable alternative for environmental remediation, including wastewater treatment. Herein, α-MoO3 and α-Fe2O3 semiconductors were synthesized at low temperature by a Pechini-based method and then applied in photocatalysis. The catalytic efficiency was performed under visible light toward the degradation of an organic persistent pollutant (Rhodamine B dye, RhB), commonly present in industries wastewater. The results indicated that the synthesized α-MoO3 or α-Fe2O3 photocatalysts presented a pronounced activity and promoted an efficient RhB degradation after 15 min of reaction. α-MoO3 had a degradation efficiency of 93% and 98%, while α-Fe2O3 showed 67% and 100% RhB degradation without and with the addition of H2O2, respectively. These results suggest that the synthesized oxides have high oxi-reductive capacity, which can be used for a fast and effective photodegradation of RhB and other organic persistent pollutants to minimize environmental impacts.

ACS Style

Herbet Sales; André Menezes; Gelmires Neves; João Souza; Jailson Ferreira; Laís Chantelle; André Menezes De Oliveira; Hélio Lira. Development of Sustainable Heterogeneous Catalysts for the Photocatalytic Treatment of Effluents. Sustainability 2020, 12, 7393 .

AMA Style

Herbet Sales, André Menezes, Gelmires Neves, João Souza, Jailson Ferreira, Laís Chantelle, André Menezes De Oliveira, Hélio Lira. Development of Sustainable Heterogeneous Catalysts for the Photocatalytic Treatment of Effluents. Sustainability. 2020; 12 (18):7393.

Chicago/Turabian Style

Herbet Sales; André Menezes; Gelmires Neves; João Souza; Jailson Ferreira; Laís Chantelle; André Menezes De Oliveira; Hélio Lira. 2020. "Development of Sustainable Heterogeneous Catalysts for the Photocatalytic Treatment of Effluents." Sustainability 12, no. 18: 7393.

Original article
Published: 07 September 2020 in International Journal of Applied Ceramic Technology
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Ceramics containing cordierite and mullite as their principal phases are promising for many applications, due to properties such as a low coefficient of thermal expansion, high durability, low dielectric constant, resistance to thermal shock, and refractoriness. The objective of this study was to produce ceramic composites suitable for use as refractory materials. The raw materials were subjected to chemical characterization and the formulations to physical, chemical, and mineralogical characterization. The specimens were formed by pressing, dried at 110°C, and sintered from 1150°C to 1300°C for 2 hours. The following properties were then determined: linear shrinkage, water absorption, apparent porosity, and flexural modulus of rupture. The phases formed, crystal morphology, and coefficient of thermal expansion were evaluated. The cordierite and mullite phases were observed in all formulations at 1250°C and 1300°C. The results obtained from the formulations with a higher content of fine kaolin residue suggest that these formulations have the potential to be used for the manufacture of refractory materials such as furnace rollers and supports.

ACS Style

Igor Pinheiro De Brito; Ester Pires De Almeida; Gelmires De Araújo Neves; Hélio De Lucena Lira; Romualdo Rodrigues Menezes; Valmir José Da Silva; Lisiane Navarro De Lima Santana. Development of cordierite/mullite composites using industrial wastes. International Journal of Applied Ceramic Technology 2020, 18, 253 -261.

AMA Style

Igor Pinheiro De Brito, Ester Pires De Almeida, Gelmires De Araújo Neves, Hélio De Lucena Lira, Romualdo Rodrigues Menezes, Valmir José Da Silva, Lisiane Navarro De Lima Santana. Development of cordierite/mullite composites using industrial wastes. International Journal of Applied Ceramic Technology. 2020; 18 (1):253-261.

Chicago/Turabian Style

Igor Pinheiro De Brito; Ester Pires De Almeida; Gelmires De Araújo Neves; Hélio De Lucena Lira; Romualdo Rodrigues Menezes; Valmir José Da Silva; Lisiane Navarro De Lima Santana. 2020. "Development of cordierite/mullite composites using industrial wastes." International Journal of Applied Ceramic Technology 18, no. 1: 253-261.

Journal article
Published: 18 August 2020 in Materials
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Multilayer-like CrN and Cr1−xAlxN coatings with different Al contents were deposited onto a stainless steel substrate using dynamic glancing angle deposition direct current magnetron sputtering (DGLAD dcMS) in a N rich atmosphere to understand the role of Al on the growth of the films and mechanical properties of the nitrides with a multilayer architecture. Chemical analysis by means of energy dispersive analysis (EDS) and glow discharge optical emission spectroscopy (GDOES) depth profiling revealed that while CrN samples were close to stoichiometric, the Cr1−xAlxN coatings presented excess N between 70 and 80% at. An expressive change in texture was observed as the CrN coating changed its preferred orientation from (111) to (200) with the addition of Al, followed by a modification in morphology from grains with faceted pyramidal tops in CrN to dome-shaped grains in Cr1−xAlxN coatings. Multilayer-like nanostructures of corrugated grains were produced with a periodicity of approximately 30 nm using dynamic glancing angle deposition. The deposition rate was drastically reduced with an increase of Al, meanwhile, the best mechanical performance was achieved for the coating with a higher content of Al, with hardness up to 27 GPa and a higher value of maximum resistance to plastic deformation.

ACS Style

Pedro Renato Tavares Avila; Alisson Mendes Rodrigues; Monica Costa Rodrigues Guimarães; Magdalena Walczak; Romualdo R. Menezes; Gelmires A. Neves; Haroldo Cavalcanti Pinto. Nitrogen-Enriched Cr1−xAlxN Multilayer-Like Coatings Manufactured by Dynamic Glancing Angle Direct Current Magnetron Sputtering. Materials 2020, 13, 3650 .

AMA Style

Pedro Renato Tavares Avila, Alisson Mendes Rodrigues, Monica Costa Rodrigues Guimarães, Magdalena Walczak, Romualdo R. Menezes, Gelmires A. Neves, Haroldo Cavalcanti Pinto. Nitrogen-Enriched Cr1−xAlxN Multilayer-Like Coatings Manufactured by Dynamic Glancing Angle Direct Current Magnetron Sputtering. Materials. 2020; 13 (16):3650.

Chicago/Turabian Style

Pedro Renato Tavares Avila; Alisson Mendes Rodrigues; Monica Costa Rodrigues Guimarães; Magdalena Walczak; Romualdo R. Menezes; Gelmires A. Neves; Haroldo Cavalcanti Pinto. 2020. "Nitrogen-Enriched Cr1−xAlxN Multilayer-Like Coatings Manufactured by Dynamic Glancing Angle Direct Current Magnetron Sputtering." Materials 13, no. 16: 3650.

Journal article
Published: 14 August 2020 in Materials
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The efficiency of acid treatment on natural calcium bentonite (natural bentonite) for anionic dye adsorption was investigated using methyl orange (MO) as a probe. Additionally, adsorption experiments were accomplished between the natural bentonite, acidified bentonite, and a cationic dye (methylene blue, MB). Acid functionalization in natural bentonite (RF) was carried out with HCl and H2SO4 acids (RF1 and RF2, respectively). The samples were characterized by chemical analysis, mineralogy, particle size, and thermal behavior with the associated mass losses. The adsorption efficiency of MO and MB dyes was investigated by the effects of the initial concentration of adsorbate (Ci) and the contact time (tc). The acid treatment was efficient for increasing the adsorption capacity of the anionic dye, and the Qmaxexp values measured were 2.2 mg/g, 67.4 mg/g e 47.8 mg/g to RF, RF1 e RF2, respectively. On the other hand, the acid functionalization of bentonite did not significantly modify the MB dye adsorption. The Sips equation was the best fit for the adsorption isotherms. Thus, we found that the acid-functionalized bentonite increases the anionic dye adsorption by up to 8000%. The increased adsorptive capacity of acidified bentonite was explained in terms of electrostatic attraction between the clay surface and the dye molecule.

ACS Style

Jucielle Veras Fernandes; Alisson Mendes Rodrigues; Romualdo Rodrigues Menezes; Gelmires De Araújo Neves. Adsorption of Anionic Dye on the Acid-Functionalized Bentonite. Materials 2020, 13, 3600 .

AMA Style

Jucielle Veras Fernandes, Alisson Mendes Rodrigues, Romualdo Rodrigues Menezes, Gelmires De Araújo Neves. Adsorption of Anionic Dye on the Acid-Functionalized Bentonite. Materials. 2020; 13 (16):3600.

Chicago/Turabian Style

Jucielle Veras Fernandes; Alisson Mendes Rodrigues; Romualdo Rodrigues Menezes; Gelmires De Araújo Neves. 2020. "Adsorption of Anionic Dye on the Acid-Functionalized Bentonite." Materials 13, no. 16: 3600.

Articles
Published: 01 March 2020 in Cerâmica
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In Brazil, bentonite clays are not naturally sodic and it is an industrial practice the sodium additivation, since sodium ion expands their lamellae allowing a larger amount of water to penetrate. The objective was to analyze the influences of the use of sodium carbonate on the clay during the additivation process, the moisture content and the cure time on cation exchange and viscosity of bentonite clay dispersions for water-based drilling fluids, since there is a shortage of studies on this subject. Newly discovered bentonite clays in Paraíba State, Brazil, were chemically, physically and mineralogically characterized and were additivated with sodium carbonate in aqueous solution (process 1) or in powder form (process 2). Samples with 25% to 60% of moisture (dry basis) were prepared and submitted to cure times of 7 to 45 days. Process 1, as expected, showed better results of cation exchange capacity, viscosity and filtrate volume. The ideal cure time was 15 days. After this period there was a reversal of the cation exchange reactions.

ACS Style

I. C. G. Morais; I. A. Silva; B. M. A. B. Buriti; J. V. Fernandes; D. S. Silva; Gelmires Araujo Neves; H. S. Ferreira. Influence of the additivation process on cation exchange capacity and viscosity of bentonitic clay dispersions. Cerâmica 2020, 66, 81 -87.

AMA Style

I. C. G. Morais, I. A. Silva, B. M. A. B. Buriti, J. V. Fernandes, D. S. Silva, Gelmires Araujo Neves, H. S. Ferreira. Influence of the additivation process on cation exchange capacity and viscosity of bentonitic clay dispersions. Cerâmica. 2020; 66 (377):81-87.

Chicago/Turabian Style

I. C. G. Morais; I. A. Silva; B. M. A. B. Buriti; J. V. Fernandes; D. S. Silva; Gelmires Araujo Neves; H. S. Ferreira. 2020. "Influence of the additivation process on cation exchange capacity and viscosity of bentonitic clay dispersions." Cerâmica 66, no. 377: 81-87.

Articles
Published: 01 March 2020 in Cerâmica
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New deposits of bentonite clays have been discovered in the Brazilian State of Paraíba; the most recent was at the municipality of Olivedos. Recent studies have discovered the presence of high levels of non-clay minerals that can produce unsatisfactory results when attempting to use these clays in drilling fluids. In order to make them suitable for this purpose, the MgO and CaCl2 as chemical additives were used and their influences on the rheological properties of these clays were analyzed, using an experimental planning technique and statistical analysis. The samples were obtained using experimental modeling by the delineation of mixtures technique; first, the clays were transformed with sodium carbonate and then dosed with MgO and CaCl2. The rheological properties, apparent viscosity (AV) and plastic viscosity (PV) were determined according to the Petrobras standard (AV≥15 cP; PV≥4 cP). The results showed that the values of AV and PV increased considerably and that MgO was the additive that contributed most to the improvement of these properties, making these additives suitable for use in water-based drilling fluids.

ACS Style

B. M. A. B. Buriti; M. E. B. Araújo; P. M. Bastos; J. M. Cartaxo; Gelmires Araujo Neves; H. S. Ferreira. Influence of MgO and CaCl2 on the rheological properties of bentonitic clays from the new Paraíba-Brazil deposits using experimental planning and statistical analysis. Cerâmica 2020, 66, 74 -80.

AMA Style

B. M. A. B. Buriti, M. E. B. Araújo, P. M. Bastos, J. M. Cartaxo, Gelmires Araujo Neves, H. S. Ferreira. Influence of MgO and CaCl2 on the rheological properties of bentonitic clays from the new Paraíba-Brazil deposits using experimental planning and statistical analysis. Cerâmica. 2020; 66 (377):74-80.

Chicago/Turabian Style

B. M. A. B. Buriti; M. E. B. Araújo; P. M. Bastos; J. M. Cartaxo; Gelmires Araujo Neves; H. S. Ferreira. 2020. "Influence of MgO and CaCl2 on the rheological properties of bentonitic clays from the new Paraíba-Brazil deposits using experimental planning and statistical analysis." Cerâmica 66, no. 377: 74-80.

Journal article
Published: 14 February 2020 in Ceramics International
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This work investigated the photocatalytic effect of silver-modified titania fibers on the degradation of rhodamine B (RB) and methylene blue (MB) and the inactivation of Escherichia coli and Staphylococcus aureus strains. Fibrous cotton-wool-like structures resulted from a combination of the sol-gel route to solution blow spinning followed by calcination of hybrids fibers at 700 °C. Analysis of X-ray diffraction and transmission electron microscopy confirmed the presence of anatase and rutile polymorphs and metallic silver on fibers. Silver-modified titania fibers inhibited bacterial growth in all experimental conditions regardless of the ion content or UV-irradiation. The effectiveness of microorganism inactivation of titania fibers increases upon UV-irradiation. pH did not influence the photodegradation of RB, and solutions with basic pH enhanced the removal of MB. In a fixed pH, MB presents a faster photodegradation rate as compared to RB, but they match when applying silver-modified titania fibers and UV-irradiation.

ACS Style

R.S. Leite; A.M.C. Santos; L.L. Severo; J.F. Duarte Neto; L.R.C. Castellano; Gelmires Araujo Neves; H.L. Lira; R.R. Menezes. Photocatalytic degradation of dyes and microorganism inactivation using solution blow spun silver-modified titania fibers. Ceramics International 2020, 46, 13482 -13490.

AMA Style

R.S. Leite, A.M.C. Santos, L.L. Severo, J.F. Duarte Neto, L.R.C. Castellano, Gelmires Araujo Neves, H.L. Lira, R.R. Menezes. Photocatalytic degradation of dyes and microorganism inactivation using solution blow spun silver-modified titania fibers. Ceramics International. 2020; 46 (9):13482-13490.

Chicago/Turabian Style

R.S. Leite; A.M.C. Santos; L.L. Severo; J.F. Duarte Neto; L.R.C. Castellano; Gelmires Araujo Neves; H.L. Lira; R.R. Menezes. 2020. "Photocatalytic degradation of dyes and microorganism inactivation using solution blow spun silver-modified titania fibers." Ceramics International 46, no. 9: 13482-13490.

Journal article
Published: 02 February 2020 in Journal of Materials Research and Technology
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Porous N-carbon/silica nanofibers (PN-CSN) were successfully made by solution blow spinning (SBS), polymer solutions containing polyvinylpyrrolidone (PVP), tetraethyl orthosilicate (TEOS), and ethanol. The fibers samples were carbonized at 550 °C in a static air atmosphere. PN-CSN fibers were characterized using scanning electron microscopy, N2 adsorption/desorption, X-ray diffraction, thermogravimetric analysis and zeta potential. The adsorption capacity was determined using a dye (methylene blue, MB). The PN-CSN fibers had a small average diameter (233 ± 178 nm), high specific surface area (364 m2 g−1) and pore volume (0.18 cm3 g−1). The pore size distribution ranged from 10 to 170 nm. Chemical analyses of the fibers revealed a residual amount of N (6.2%) and C (20,85%) as is characteristic in ceramic nanofibers made with polyacrylonitrile (PAN). The PN-CSN fibers had an adsorption capacity of approximately 400 mg g−1. The best fit for the adsorption data was found using a Langmuir model. The adsorption kinetics followed a pseudo-second order model. Thermodynamic analyses revealed the adsorption mechanism was endothermic and spontaneous for PN-CSN adsorbents.

ACS Style

Rosiane Maria Da Costa Farias; Mariaugusta Ferreira Mota; Lucas Leite Severo; Eliton Souto de Medeiros; Artur P. Klamczynski; Roberto De Jesús Avena-Bustillos; Lisiane Navarro De Lima Santana; Gelmires Araujo Neves; Gregory Melvin Glenn; Romualdo Menezes. Green synthesis of porous N-Carbon/Silica nanofibers by solution blow spinning and evaluation of their efficiency in dye adsorption. Journal of Materials Research and Technology 2020, 9, 3038 -3046.

AMA Style

Rosiane Maria Da Costa Farias, Mariaugusta Ferreira Mota, Lucas Leite Severo, Eliton Souto de Medeiros, Artur P. Klamczynski, Roberto De Jesús Avena-Bustillos, Lisiane Navarro De Lima Santana, Gelmires Araujo Neves, Gregory Melvin Glenn, Romualdo Menezes. Green synthesis of porous N-Carbon/Silica nanofibers by solution blow spinning and evaluation of their efficiency in dye adsorption. Journal of Materials Research and Technology. 2020; 9 (3):3038-3046.

Chicago/Turabian Style

Rosiane Maria Da Costa Farias; Mariaugusta Ferreira Mota; Lucas Leite Severo; Eliton Souto de Medeiros; Artur P. Klamczynski; Roberto De Jesús Avena-Bustillos; Lisiane Navarro De Lima Santana; Gelmires Araujo Neves; Gregory Melvin Glenn; Romualdo Menezes. 2020. "Green synthesis of porous N-Carbon/Silica nanofibers by solution blow spinning and evaluation of their efficiency in dye adsorption." Journal of Materials Research and Technology 9, no. 3: 3038-3046.

Journal article
Published: 13 January 2020 in Revista Eletrônica em Gestão, Educação e Tecnologia Ambiental
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The mixture of mortars with quartzite residues is a recycling technique that has been widely used to promote the adequate management of solid waste generated in the municipality of Várzea-PB, Brazil. However, there are no reports in the literature that prove the durability of the mortar mixed with these residues when subjected to environmental conditions over time. Thus, the present work has as objective to study the durability of mortars incorporated with quartzite residues when submitted to natural aging. The reference mortar and incorporated with quartzite were prepared according to NBR 13281 and submitted to natural aging for 28, 60, 120, 180 and 360 days. Then, they were characterized by x-ray diffraction, thermogravimetric analysis and simple compression strength and carbonation and pozzolanic measurements. The results showed that, despite the decrease in compressive strength of quartzite containing mortars, the durability was not compromised, since the values were maintained in the range suggested by NBR 13281. Finally, it was concluded that mortars produced with quartzite residues presented good mechanical behavior when submitted to natural aging.

ACS Style

Sâmea Valensca Alves Barros; Gerbeson Carlos Batista Dantas; António Santos Silva; Gelmires De Araújo Neves; Romualdo Rodrigues Menezes; André Luiz Fiquene De Brito; Patrícia Mendonça Pimentel; Stefeson Bezerra De Melo. Behavior of mortar blended with quartzite residues when subjected to natural aging. Revista Eletrônica em Gestão, Educação e Tecnologia Ambiental 2020, 24, 14 .

AMA Style

Sâmea Valensca Alves Barros, Gerbeson Carlos Batista Dantas, António Santos Silva, Gelmires De Araújo Neves, Romualdo Rodrigues Menezes, André Luiz Fiquene De Brito, Patrícia Mendonça Pimentel, Stefeson Bezerra De Melo. Behavior of mortar blended with quartzite residues when subjected to natural aging. Revista Eletrônica em Gestão, Educação e Tecnologia Ambiental. 2020; 24 ():14.

Chicago/Turabian Style

Sâmea Valensca Alves Barros; Gerbeson Carlos Batista Dantas; António Santos Silva; Gelmires De Araújo Neves; Romualdo Rodrigues Menezes; André Luiz Fiquene De Brito; Patrícia Mendonça Pimentel; Stefeson Bezerra De Melo. 2020. "Behavior of mortar blended with quartzite residues when subjected to natural aging." Revista Eletrônica em Gestão, Educação e Tecnologia Ambiental 24, no. : 14.

Artigos
Published: 01 January 2020 in Matéria (Rio de Janeiro)
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RESUMO Resíduos de MDF (MediumDensityFiberboard) gerados nas indústrias de móveis de madeiras, geralmente, são depositados em locais inadequados, causando impactos ambientais. Este trabalho teve como objetivo desenvolver materiais porosos com a incorporação de resíduo de MDF (5, 10 e 15% de resíduo) em massas cerâmicas estruturais. As características mineralógicas, químicas e térmicas das massas foram analisadas. Corpos de prova (50mm x15mm x 5mm) foram conformados por prensagem uniaxial (13,3 MPa), os quais foram secos à 110 ºC/24 h e sinterizados à 750, 850 e 950 °C. Posteriormente, estes foram submetidos às seguintes caracterizações: absorção de água, densidade aparente, porosidade aparente e módulo de ruptura à flexão. As características mineralógicas e microestruturais, após queima, também foram analisadas. Os resultados evidenciaram que, até 10% do resíduo de MDF em forma de pó, poderá ser incorporado em massas cerâmicas estruturais para produção de materiais cerâmicos, como blocos porosos isolantes acústicos e térmicos. A porosidade aparente foi de 31,7%, a densidade aparente foi de 1,6 g/cm3 e o módulo de ruptura a flexão foi de 11,5 MPa.

ACS Style

Ester Pires De Almeida; Túlio Galvão Apolônio; Heber Carlos Ferreira; Gelmires De Araújo Neves; Lisiane Navarro De Lima Santana; Romualdo Rodrigues Menezes. Preparação de blocos porosos utilizando resíduos de MDF na formulação de massas cerâmicas estruturais. Matéria (Rio de Janeiro) 2020, 25, 1 .

AMA Style

Ester Pires De Almeida, Túlio Galvão Apolônio, Heber Carlos Ferreira, Gelmires De Araújo Neves, Lisiane Navarro De Lima Santana, Romualdo Rodrigues Menezes. Preparação de blocos porosos utilizando resíduos de MDF na formulação de massas cerâmicas estruturais. Matéria (Rio de Janeiro). 2020; 25 (1):1.

Chicago/Turabian Style

Ester Pires De Almeida; Túlio Galvão Apolônio; Heber Carlos Ferreira; Gelmires De Araújo Neves; Lisiane Navarro De Lima Santana; Romualdo Rodrigues Menezes. 2020. "Preparação de blocos porosos utilizando resíduos de MDF na formulação de massas cerâmicas estruturais." Matéria (Rio de Janeiro) 25, no. 1: 1.

Journal article
Published: 01 September 2019 in Cerâmica
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Resumo Mulita é um aluminossilicato com grande importância na tecnologia cerâmica. Sua síntese através de métodos químicos tem sido extensivamente estudada, no entanto, não se observam estudos da sua obtenção pelo método Pechini. Assim, este estudo teve por objetivo a síntese de mulita por meio deste método. Foi avaliada a influência de diversos solventes na obtenção da mulita pela rota Pechini. As características dos pós foram avaliadas por difração de raios X, análise térmica (TG/DTG), adsorção de nitrogênio (BET), microscopia eletrônica de varredura e de transmissão. Os resultados obtidos comprovaram a eficiência do método Pechini, bem como a influência dos solventes na obtenção da fase, sendo a mulita obtida como fase majoritária e com maior cristalinidade quando do uso do álcool etílico como solvente.

ACS Style

A. N. S. Braga; V. N. Simões; H. L. Lira; G. A. Neves; R. R. Menezes. Influência do tipo de solvente na síntese de mulita pelo método Pechini. Cerâmica 2019, 65, 388 -393.

AMA Style

A. N. S. Braga, V. N. Simões, H. L. Lira, G. A. Neves, R. R. Menezes. Influência do tipo de solvente na síntese de mulita pelo método Pechini. Cerâmica. 2019; 65 (375):388-393.

Chicago/Turabian Style

A. N. S. Braga; V. N. Simões; H. L. Lira; G. A. Neves; R. R. Menezes. 2019. "Influência do tipo de solvente na síntese de mulita pelo método Pechini." Cerâmica 65, no. 375: 388-393.