Glycerol, a by-product from biodiesel production can react with di-carboxylic organic acids, resulting in polyesters, and can be used in the composition of urea/formaldehyde or phenol/formaldehyde resins to improve the qualities of adhesion and moisture resistance of them. In this work, six kinds of resins derived from glycerol, named as GAA (glycerol/adipic acid), GAAU (glycerol/adipic acid/urea), GAF (glycerol/phtalic acid), GU (glycerol/urea), GUF (glycerol/urea/formaldehyde) and GF (glycerol/formaldehyde), were synthesized. The resins derived from carboxylic acids had better thermal stability (up to 350 ºC) than those derived from formaldehyde (up to 200 ºC). The average molecular weights of the resins were determined by matrix assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) and gel-permeation chromatography (GPC), and are in the range of 1800-2800 Da, being oligomers, and the polydispersity indexes are in the range of 1.3 to 1.8. The ¹H and 13C nuclear magnetic resonance (NMR) techniques were used to identify the structure of the resins.

In the present study, powders of α-Ag₂WO₄ (PAW) and β-Ag₂MoO₄ (PAM) were prepared through the coprecipitation method, while poly(vinyl alcohol) nanofibers (FPVA) and composite nanofibers of PVA/α-Ag₂WO₄ (FPAW) and PVA/β-Ag₂MoO₄ (FPAM) were prepared using the electrospinning technique. Several characterization techniques were applied to evaluate the structure of the obtained materials, as well as studies for assessing their antimicrobial properties. The antimicrobial activities of the composites against Pseudomonas aeruginosa and Staphylococcus aureus were investigated through the minimum inhibitory concentration (MIC) and the minimum bactericidal concentration (MBC). Our studies demonstrated that materials exhibit antibacterial activity against P. aeruginosa (MIC/MBC = 0.014/ND mg mL^-1 for PAW; MIC/MBC = 1.43/1.43 for PAM; MIC/MBC = 1.35/1.35 mg mL^-1 for FPAW; MIC/MBC = 3.68/11.03 mg mL^-1 for FPAM and MIC/MBC = 8.78/ND mg mL^-1 for FPVA) and S. aureus (MIC/MBC = 0.794/ND mg mL^-1 for PAW; MIC/MBC = 1.43/ND for PAM; MIC/MBC = 1.35/1.35 mg mL^-1 for FPAW; MIC/MBC = 3.68/3.67 mg mL^-1 FPAM and MIC/MBC = 14.63/* mg mL^-1 for FPVA). The cytotoxic concentrations (CC₅₀, μg mL^-1) against the VERO cells were 21.74 ± 0.04 for PAW, 1000 for FPVA, thus indicating that the immobilization of the semiconductor to the FPVA mats decreases the cytotoxic effect of the materials studied as compared to not immobilized ones. The results suggest that powders and composite polymeric mats displayed antimicrobial action that was attributed to the production of reactive oxygen species (ROS), which are responsible for inducing high local oxidative stress, causing the death of both types of bacteria.

This work describes the preparation of babassu, castor oil biodiesel and mixtures in various proportions of these oils, using alkaline compounds of strontium (SrCO3 + SrO + Sr (OH)2) as heterogeneous catalysts. The mixture of oils of these oleaginous sources was used in the production of biodiesel with quality parameters that meet current legislation. The catalyst was characterized by X-ray diffractometry (XDR), physisorption of gas (BET method), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDX) and Fourier transform infrared spectroscopy (FTIR). The viscometric technique was used to monitor the optimization. The transesterification reactions performed using strontium compounds reached conversion rates of 97.2% babassu biodiesel (BB), 96.4% castor oil biodiesel (COB) and 95.3% Babassu/Castor Oil Biodiesel 4:1 (BBCO41). Printed in Brazil - ©2013 Sociedade Brasileira de Química

Modified clays with organic molecules have many applications, such as the adsorption of pollutants, catalysts, and drug delivery systems. Different methodologies for intercalating these structures with organic moieties can be found in the literature with many purposes. In this paper, a new methodology of modifying Sodium Montmorillonite clays (Na-Mt) with a faster drying time was investigated by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), BET, and thermogravimetric analysis (TG and DTG). In the modification process, a mixture of ethyl alcohol, DMSO, and Na-Mt were kept under magnetic stirring for one hour. Statistical analysis was applied to evaluate the effects of the amount of DMSO, temperature, and sonication time on the modified clay (DMSO-SMAT) using a 2³-factorial design. XRD and FTIR analyses showed the DMSO intercalation into sodium montmorillonite Argel-T (SMAT). An average increase of 0.57 nm for the interplanar distance was found after swelling with DMSO intercalation. BET analysis revealed a decrease in the surface area (from 41.8933 m²/g to 2.1572 m²/g) of Na-Mt when modified with DMSO. The porosity increased from 1.74 (SMAT) to 1.87 nm (DMSO-SMAT) after the application of the methodology. Thermal analysis showed a thermal stability for the DMSO-SMAT material, and this was used to calculate the DMSO-SMAT formula of Na[Al₅Mg]Si₁₂O₃₀(OH)₆ · 0.54 DMSO. Statistical analysis showed that only the effect of the amount of DMSO was significant for increasing the interlayer space of DMSO-SMAT. In addition, at room temperature, the drying time of the sample using this methodology was 30 min.

O presente trabalho, apresenta um relato sobre a atividade realizada durante a II semana da química no IFCE – Campus Aracati, organizada e desenvolvida pelos bolsistas do PIBID e realizada juntamente

A coleção “Atividades de Ensino e de Pesquisa em Química” é uma obra que tem um conjunto fundamental de conhecimentos direcionados a industriais, pesquisadores, engenheiros, técnicos, acadêmicos e, é claro, estudantes. A coleção abordará de forma categorizada pesquisas que transitam nos vários caminhos da química de forma aplicada, inovadora, contextualizada e didática objetivando a divulgação científica por meio de trabalhos com diferentes funcionalidades que compõem seus capítulos. O objetivo central foi apresentar de forma categorizada e clara estudos relacionados ao desenvolvimento de protótipo de baixo custo, análise do perfil químico de extratos, degradação de resinas, quantificação de flavonoides, estudo de substâncias antioxidantes e avaliação do grau de contaminação das águas. Em todos esses trabalhos a linha condutora foi o aspecto relacionado ao desenvolvimento, otimização e aplicação, entre outras abordagens importantes na área de química, ensino e engenharia química. Atividades de Ensino e de Pesquisa em Química 4 tem sido um fator importante para a contribuição em diferentes áreas de ensino e pesquisa. Temas diversos e interessantes são, deste modo, discutidos aqui com a proposta de fundamentar o conhecimento de acadêmicos, mestres e todos aqueles que de alguma forma se interessam pela área de química. Possuir um material que demonstre evolução de diferentes metodologias, abordagens, aplicações de processos, caracterização substanciais é muito relevante, assim como abordar temas atuais e de interesse tanto no meio acadêmico como social. Portanto, esta obra é oportuna e visa fornecer uma infinidade de estudos fundamentados nos resultados experimentais obtidos pelos diversos pesquisadores, professores e acadêmicos que desenvolveram seus trabalhos que aqui serão apresentados de maneira concisa e didática. Jéssica Verger Nardeli