Resumen Este artículo tiene como objetivo presentar y discutir los aportes del uso del role-play, desde el juego de rol inglés, en la introducción de temas de Educación Ambiental para la promoción de la formación crítica y reflexiva. Para eso, se elaboró y aplicó una actividad de simulación de Asamblea Escolar con nueve estudiantes de Enseñanza Media y Superior, matriculados en una unidad del Instituto Federal de Educação, Ciência e Tecnologia de São Paulo (IFSP), locus de la investigación, para discutir la disposición de residuos sólidos y la relación entre producción, consumo y sociedad. Se realizó una investigación cualitativa con características de la investigación-acción. Para la recolección de datos se utilizó la observación participante, grabaciones de las reuniones y análisis de las propuestas elaboradas por los sujetos de investigación. Los datos fueron analizados en base al análisis en prosa y los resultados sugieren que el uso del role-play contribuye a la formación integral al fomentar el pensamiento crítico y reflexivo, la argumentación y el respeto por la opinión de los pares.

Resumo Este artigo tem como objetivo apresentar e discutir as contribuições da utilização do role-play, do inglês jogo de papéis, na introdução de assuntos da Educação Ambiental para a promoção da formação crítica e reflexiva. Para tanto, foi elaborada uma atividade de simulação de Assembleia Escolar e aplicada com nove estudantes do Ensino Médio e do Ensino Superior, matriculados em uma unidade do Instituto Federal de Educação, Ciência e Tecnologia de São Paulo (IFSP), locus da pesquisa, para discutir sobre o descarte de resíduos sólidos e a relação entre produção, consumo e sociedade. Foi realizada uma investigação qualitativa com características da pesquisa-ação. Para a coleta dos dados utilizou-se a observação participante, gravações dos encontros e análise das propostas elaboradas pelos sujeitos da pesquisa. Os dados foram analisados com base na análise de prosa e os resultados sugerem que a utilização do role-play contribui para a formação integral ao estimular o pensamento crítico e reflexivo, a argumentação e o respeito pela opinião do colega.

Abstract This article aims to present and discuss the contributions of the use of role-play in the introduction of Environmental Education issues for the promotion of critical and reflexive education. For this purpose, a School Assembly simulation activity was developed and applied to nine students from High School and College Education enrolled in the IFSP (Instituto Federal de Educação, Ciência e Tecnologia de São Paulo) unit, search locus, to discuss the disposal of solid waste and the relationship between production, consumption and society. A qualitative investigation was conducted with action research characteristics. For data collection, participant observation, recording of the meetings and analysis of the proposals elaborated by research subjects were used. These data were analysed based on prose analysis and the results suggest that the use of role-play contributes to integral education by encouraging critical and reflective thinking, argumentation and respect for other colleagues’ opinions.

The aim of this work was to contribute to the creation of new ways of treating wastewater contaminated with Cr3+, based on solid-liquid adsorption. An adsorbent material was prepared by functionalization of kaolinite with glycerin biodiesel by-product. This material was tested for adsorption performed using a batch method, and results showed that inclusion of glycerin in the structure of kaolinite led to a significant increase in the capacity of Cr3+ adsorption. This contributes to the allocation of by-product of biodiesel and to the treatment of effluents from tanneries.

This work describes the hydrolytic sol-gel synthesis of silica particles prepared by a modified Stöber route, using the organofunctionalized alkoxide 3-methacryloxypropyl trimethoxysilane and tetraethylorthosilicate. The silica particles were obtained through basic catalysis from a mixture of precursor alkoxides, water, and isopropyl alcohol. Samples were prepared with change to the pre-hydrolysis and condensation time of tetraethylortosilicate, followed by addition of the organosilane 3-methacryloxypropyl trimethoxysilane. Eu3+ ions were added to the alkoxides mixture, in order to obtain structural information about the silica particles. The samples were centrifuged, washed with ethanol, and dried at 50 ºC. The xerogel was analyzed by thermogravimetric analysis, photoluminescence, transmission electron microscopy, and infrared spectroscopy. The photoluminescence spectra revealed Eu3+ lines characteristic of the ion 5D0 <img src="/img/revistas/mr/2011nahead/aop_0408-10_set.jpg" alt="" align="absmiddle"> 7F J (J = 0, 1, 2, 3, 4) transition. The thermogravimetric curve and infrared spectra confirmed the presence of the alkoxide organic group and water in the materials. Transmission electron microscopy showed spherical particles with varied size. The time of pre-hydrolysis and condensation as well as the addition of 3-methacryloxypropyl trimethoxysilane affect the final shape and size of the materials, so they can be used as control factors.

The sol-gel process is very effective for the preparation of new materials with potential applications in optics, sensors, catalyst supports, coatings, and specialty inorganic polymers that can be used as hosts for the accommodation of organic molecules. The low temperature employed in the process is the main advantage of this methodology. In this work, the europium (III) complex with 1,10-phenantroline was prepared, and this luminescent complex was incorporated into silica nanoparticles and films by the sol-gel process. The nanoparticles were obtained by the modified Stöber methodology. The films were obtained by the dip-coating technique, at different deposition rates and numbers of layers. The nanoparticles and films were characterized by photoluminescence, thermal analysis, and Raman and infrared spectroscopies. Characterization revealed that the europium (III) complex was not affected upon incorporation into the nanoparticles and films, opening a new field for the application of these materials.

O objetivo deste estudo foi demonstrar a sinterização pelo método sol-gel não-hidrolítico de um cimento de ionômero de vidro experimental (CIV) e avaliar sua biocompatibilidade em relação a um cimento de ionômero de vidro convencional (Vidrion R). Quatro tubos de polietileno contendo os cimentos testados foram implantados no dorso de 15 ratos, da seguinte maneira: GI - CIV Experimental e GII - CIV Convencional. A lateral do tubo foi considerada Grupo Controle. Os ratos foram sacrificados em 7, 21 e 42 dias pós-implantação para análise histopatológica. Uma escala de I a IV foi utilizada como sistema de score para graduar a reação inflamatória. Em relação à sinterização do CIV experimental, as análises termogravométrica e por difração de raio-x demonstraram a formação de material vítreo aos 110oC pelo método sol-gel. Para o teste de biocompatibilidade, os resultados mostraram uma reação inflamatória moderada para o GI (III), severa para o GII (IV) e branda para o Grupo Controle (II) aos 7 dias. Após 21 dias, GI apresentou uma reação branda (II); GII, moderada (III) e Grupo Controle, branda (II). Aos 42 dias, GI apresentou uma reação inflamatória branda/ausente (II a I), similar ao GII (II a I). O Grupo Controle demonstrou ausência de reação inflamatória (I). Concluiu-se que o CIV Experimental apresentou reação tecidual branda/ausente após 42 dias, sendo biocompatível quando testado em tecido conjuntivo de ratos.

The aims of this study were to demonstrate the synthesis of an experimental glass ionomer cement (GIC) by the non-hydrolytic sol-gel method and to evaluate its biocompatibility in comparison to a conventional glass ionomer cement (Vidrion R). Four polyethylene tubes containing the tested cements were implanted in the dorsal region of 15 rats, as follows: GI - experimental GIC and GII - conventional GIC. The external tube walls was considered the control group (CG). The rats were sacrificed 7, 21 and 42 days after implant placement for histopathological analysis. A four-point (I-IV) scoring system was used to graduate the inflammatory reaction. Regarding the experimental GIC sintherization, thermogravimetric and x-ray diffraction analysis demonstrated vitreous material formation at 110oC by the sol-gel method. For biocompatibility test, results showed a moderate chronic inflammatory reaction for GI (III), severe for GII (IV) and mild for CG (II) at 7 days. After 21 days, GI presented a mild reaction (II); GII, moderate (III) and CG, mild (II). At 42 days, GI showed a mild/absent inflammatory reaction (II to I), similar to GII (II to I). CG presented absence of chronic inflammatory reaction (I). It was concluded that the experimental GIC presented mild/absent tissue reaction after 42 days, being biocompatible when tested in the connective tissue of rats.

Glass ionomer cements are widely employed in dentistry due to their physical, biological and mainly anti-caries properties. Glass ionomers consist of an aluminosilicate glass matrix modified with other elements, and they contain large quantities of fluorine. In this study, we report on the preparation of calcium-fluoroaluminosilicate glasses by a nonhydrolytic sol-gel route as an alternative approach to obtaining alumina-silica matrices. The glass powders were prepared via the non-hydrolytic sol-gel method, by mixing AlCl3, SiCl4, CaF2, AlF3, NaF, and AlPO4. The powders were studied by thermal analysis (TG/DTA/DSC), photoluminescence (PL), nuclear magnetic resonance (NMR27Al-29Si), and X ray diffraction (XRD). TG/DTA/DSC analyses revealed a constant mass loss due to structural changes during the heating process, which was confirmed by NMR and PL. A stable aluminosilicate matrix with potential future application as a glass ionomer base was obtained.

TiO2 films have various applications, among them solar cells and photodegradation of pollutants. In this study, we investigated TiO2 films functionalized with the organic dye cyanidin extracted from black mulberry (Morus nigra). The TiO2 was functionalized by the sol-gel method and the film was deposited on glass substrates by dip-coating. Our aim was to investigate the interaction between the semiconductor and the dye, as well as the influence of the velocity and number of deposits on the characteristics of the film. Using ultraviolet-visible spectroscopy, we observed a shift from the maximum absorption band at 545 nm for the dye’s ethanol solution to 595 nm for the film, indicating interaction of the cyanidin with the TiO2. The absorption spectra in the infrared region of the functionalized TiO2 particles showed bands characteristic of the oxide and indicated their interaction with the dye. Using profilometry and m-line techniques, we found that the films presented thicknesses in the order of 100 nm. A SEM analysis confirmed the high density of the films.

In this work, we report the synthesis and the photoluminescence features of a Eu(III)-doped modified silica matrix obtained by the sol-gel method. The matrix was prepared by reaction between tetraethylorthosilicate and phenyltriethoxysilane alkoxide. The hydrolysis occurred using basic catalysis. The solids were treated at 100, 200 and 300 ºC during 4 h and the structure was determined by thermogravimetric analysis (TG/DTG), nuclear magnetic resonance (NMR 29Si and 13C), infrared spectroscopy (IR) and photoluminescence (PL). The PL spectra display the Eu(III) lines characteristic of the ion, 5D0 -> 7F J (J=0, 1, 2, 3, 4), the blue emission as ascribed in the silica matrix. The NMR and TG showed the stability of hybrid silica.

In this work titanium sol was prepared from tetraethylorthotitanate (TEOT) in ethanol, stabilized with beta-diketonate 2,4 pentanedione in molar ratio 1:1 homogenized by magnetic stirring, europium ion was add as structural probe. The xerogels were heat treated at 500, 750 and 1000 °C and the characterization was realized by x-ray diffraction (XRD), transmission electron microscopy (TEM), thermogravimetric analysis (TGA/DSC) and photoluminescence (PL). The excitation spectra of Eu (III) ion present maximum in 394 nm correspondent to 5L6 level and emission spectra present bands characteristic transitions arising from the 5 D0 -> 7F J (J = 0, 1, 2, 3, 4) manifolds to samples treat at 500 and 750 °C. The Eu (III) emission disappear, when heated at 1000 °C, probably due to phase transition anatase to rutile and migrations of ions to the external surface that was proved by x-ray diffraction, transmission electronic microscopy and the thermogravimetric analyses of xerogels.

The sol-gel process is a methodology used to obtain organic-inorganic hybrid solids, which open new possibilities in the field of material science. The sol-gel technique offers a low temperature attractive approach for introducing organic molecules into amorphous materials. In order to introduce tetrakis (2-hydroxy-5-nitrophenyl)porphyrin covalently bounded to a silicate matrix, the inorganic precursor 3-isocyanatopropyltriethoxysilane was added (molar ratio 2:1) to the porphyrin solution in anhydrous dimethylformamide and triethylamine. The isolated porphyrin and the hybrid porphyrinosilica have excitation maximum centred at 400 nm and 424 nm, respectively and the emission spectra for both materials has bands centred at 650 nm and 713 nm. The formation of hybrid matrix was investigated by FTIR.