Síntese, caracterização e aplicação de MCM-41 funcionalizado com diisopropilamina no processo de adsorção do dióxido de carbono

Emissions of CO2 in the atmosphere have increased successively by various mechanisms caused by human action, especially as fossil fuel combustion and industrial chemical processes. This leads to the increase in average temperature in the atmosphere, which we call global warming. The search for new technologies to minimize environmental impacts arising from this phenomenon has been investigated. The capture of CO2 is one of the alternatives that can help reduce emis ions of greenhouse gases. The CO2 can be captured through the process of selective adsorption using adsorbents for this purpose. Were synthesized by hydrothermal method, materials of the type MCM-41 and Al-MCM-41 in the molar ratio Si / Al equal to 50. The synthesis of gels were prepared from a source of silicon, sodium, water and aluminum in the case of Al-MCM-41. The period of synthesis of the materials was 5 days in autoclave at 100°C. After that time materials were filtered, washed and dried in greenhouse at 100 º C for 4 hours and then calcined at 450 º C. Then the calcined material was functionalized with the Di-isopropylamine (DIPA) by the method of wet impregnation. We used 0.5 g of material mesopores to 3.5 mL of DIPA. The materials were functionalized in a closed container for 24 hours, and after this period were dried at brackground temperature for 2 hours. Were subsequently subjected to heat treatment at 250°C for 1 hour. These materials were used for the adsorption of CO2 and were characterized by XRD, FT-IR, BET / BJH, SEM, EDX and TG / DTG. Tests of adsorption of CO2 was carried out under the following conditions: 100 mg of adsorbent, temperature of 75°C under flow of 100 mL/min of CO2 for 2 hours. The desorption of CO2 was carried out by thermogravimetry from ambient temperature to 900ºC under flow of 25 mL min of He and a ratio of 10ºC/min. The difratogramas X-ray for the synthesized samples showed the characteristic peaks of MCM-41, showing that the structure of it was obtained. For samples functionalized there was a decrease of the intensities of these peaks, with a consequent reduction in the structural ordering of the material. However, the structure was preserved mesopores. The adsorption tests showed that the functionalized MCM-41 is presented as a material promising adsorbent, for CO2 capture, with a loss of mass on the desorption CO2 of 7,52%, while that in Al-MCM- 41 functionalized showed no such loss

Banana Peel Applied to the Solid Phase Extraction of Copper and Lead from River Water: Preconcentration of Metal Ions with a Fruit Waste

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Synthesis, characterization, and application of modified silica in the removal and preconcentration of lead ions from natural river water

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Síntese, caracterização e estudo fotofísico de complexos de 4,4- diaminoestilbeno-2,2-dissulfonato com íons lantanídeos

This is a work involving fundamental studies of chemistry where the synthesis and structural characterization, as well as a possible future application of these new compounds as luminescent sensors or sunscreen agents, complexes with 4,4 diaminostilbene-2,2-disulfonic (DSD) and trivalent lanthanide ions La3+, Nd3+, Eu3+, Gd3+ and Yb3+, were synthesized in the ratio of 3 mmol: 1 mmol (DSD: lanthanides). The complexes obtained with these ions were present in powder form and were characterized by complexometric titration with EDTA CHN Elemental analysis, molecular absorption spectroscopy in the ultraviolet region, the absorption spectroscopy in the infrared, thermal analysis (TG / DTG), Nuclear Magnetic Resonance - NMR 1H and Luminescence Spectroscopy. The complexometric titration and CHN analysis, confirmed the TG / DTG which suggest that these complexes have the following general chemical formulas: [La2(C14H12S2O6N2)2(H2O)2Cl2].7H2O,[Nd2(C14H12S2O6N2)2(H2O)2Cl2].6H2O,[Eu2(C14 H12S2O6N2)2(H2O)2Cl2].7H2O,[Gd2(C14H12S2O6N2)2(H2O)2Cl2].4H2O e [Yb2(C14H12S2O6N2)2(H2O)2].6H2O. The disappearance of the bands in the infrared spectrum at 2921 cm-1 and 2623 cm-1 and the displacement of the bands in the spectra of the amine complex indicate that the lanthanide ion is coordinated to the oxygen atoms and the sulfonate groups of the nitrogens amines, suggesting the formation of the dimer. The disappearance of the signal and the displacement signal SO3H amines in the 1H NMR spectrum of this complex are also indicative coordination and dimer formation. The Thermogravimetry indicates that the DSD is thermally stable in the range of 40º to 385°C and their complexes with lanthanide ions exhibit weight loss between 4 and 5 stages. The Uv-visible spectra indicated that the DSD and complexes exhibit cis isomers. The analysis of luminescence indicates that the complexes do not exhibit emission in the region of the lanthanides but an intense emission part of the binder. This is related to the triplet states of the ligand, which are in the lowest energy state emitting lanthanide ions, and also the formation of the dimer that suppress the luminescence of ion Eu3+. The formation of dimer was also confirmed by calculating the europium complex structure using the model Hamiltonian PM6 and Sparkle

Estudo de materiais mesoporosos funcionalizados com diferentes aminas para captura do dióxido de carbono através do processo de adsorção

Intensive use of machinery and engines burning fuel dumps into the atmosphere huge amounts of carbon dioxide (CO2), causing the intensification of the greenhouse effect. Climate changes that are occurring in the world are directly related to emissions of greenhouse gases, mainly CO2, gases, mainly due to the excessive use of fossil fuels. The search for new technologies to minimize the environmental impacts of this phenomenon has been investigated. Sequestration of CO2 is one of the alternatives that can help minimize greenhouse gas emissions. The CO2 can be captured by the post-combustion technology, by adsorption using adsorbents selective for this purpose. With this objective, were synthesized by hydrothermal method at 100 °C, the type mesoporous materials MCM - 41 and SBA-15. After the synthesis, the materials were submitted to a calcination step and subsequently functionalized with different amines (APTES, MEA, DEA and PEI) through reflux method. The samples functionalized with amines were tested for adsorption of CO2 in order to evaluate their adsorption capacities as well, were subjected to various analyzes of characterization in order to assess the efficiency of the method used for functionalization with amines. The physic-chemical techniques were used: X- ray diffraction (XRD), nitrogen adsorption and desorption (BET/BJH), scanning electron microscopy (SEM), transmission electron microscopy (TEM), CNH Analysis, Thermogravimetry (TG/DTG) and photoelectron spectroscopy X-ray (XPS). The CO2 adsorption experiments were carried out under the following conditions: 100 mg of adsorbent, at 25 °C under a flow of 100 ml/min of CO2, atmospheric pressure and the adsorption variation in time 10-210 min. The X-ray diffraction with the transmission electron micrographs for the samples synthesized and functionalized, MCM-41 and SBA-15 showed characteristic peaks of hexagonal mesoporous structure formation, showing the structure thereof was obtained. The method used was efficient reflux according to XPS and elemental analysis, which showed the presence of amines in the starting materials. The functionalized SBA -15 samples were those that had potential as best adsorbent for CO2 capture when compared with samples of MCM-41, obtaining the maximum adsorption capacity for SBA-15-P sample

Interações entre a carboximetilcelulose, carbonato de cálcio e bentonita: repercussões sobre as propriedades dos fluidos de perfuração aquosos

The role of carboxymethylcellulose (CMC) in association to calcium carbonate particles (CaCO3) in most water-based drilling fluids is to reduce the fluid loss to the surrounding formation. Another essential function is to provide rheological properties capable of maintaining in suspension the cuttings during drilling operation. Therefore, it is absolutely essential to correlate the polymer chemical structure (degree of substitution, molecular weight and distribution of substituent) with the physical-chemical properties of CaCO3, in order to obtain the better result at lower cost. Another important aspect refers to the clay hydration inhibitive properties of carboxymethylcellulose (CMC) in drilling fluids systems. The clay swelling promotes an undesirable damage that reduces the formation permeability and causes serious problems during the drilling operation. In this context, this thesis consists of two main parts. The first part refers to understanding of interactions CMC-CaCO3, as well as the corresponding effects on the fluid properties. The second part is related to understanding of mechanisms by which CMC adsorption occurs onto the clay surface, where, certainly, polymer chemical structure, ionic strength, molecular weight and its solvency in the medium are responsible to affect intrinsically the clay layers stabilization. Three samples of carboximetilcellulose with different molecular weight and degree of substitution (CMC A (9 x 104 gmol DS 0.7), CMC B (2.5 x 105 gmol DS 0.7) e CMC C (2.5 x 105 gmol DS 1.2)) and three samples of calcite with different average particle diameter and particle size distribution were used. The increase of CMC degree of substitution contributed to increase of polymer charge density and therefore, reduced its stability in brine, promoting the aggregation with the increase of filtrate volume. On the other hand, the increase of molecular weight promoted an increase of rheological properties with reduction of filtrate volume. Both effects are directly associated to hydrodynamic volume of polymer molecule in the medium. The granulometry of CaCO3 particles influenced not only the rheological properties, due to adsorption of polymers, but also the filtration properties. It was observed that the lower filtrate volume was obtained by using a CaCO3 sample of a low average size particle with wide dispersion in size. With regards to inhibition of clay swelling, the CMC performance was compared to other products often used (sodium chloride (NaCl), potassium chloride (KCl) and quaternary amine-based commercial inhibitor). The low molecular weight CMC (9 x 104 g/mol) showed slightly lower swelling degree compared to the high molecular weight (2.5 x 105 g/mol) along to 180 minutes. In parallel, it can be visualized by Scanning Electron Microscopy (SEM) that the high molecular weight CMC (2.5 x 105 g/mol e DS 0.7) promoted a reduction in pores formation and size of clay compared to low molecular weight CMC (9.0 x 104 g/mol e DS 0.7), after 1000 minutes in aqueous medium. This behavior was attributed to dynamic of interactions between clay and the hydrodynamic volume of CMC along the time, which is result of strong contribution of electrostatic interactions and hydrogen bounds between carboxylate groups and hydroxyls located along the polymer backbone and ionic and polar groups of clay surface. CMC adsorbs on clay surface promoting the skin formation , which is responsible to minimize the migration of water to porous medium. With the increase of degree of substitution, it was observed an increase of pores onto clay, suggesting that the higher charge density on polymer is responsible to decrease its flexibility and adsorption onto clay surface. The joint evaluation of these results indicate that high molecular weight is responsible to better results on control of rheological, filtration and clay swelling properties, however, the contrary effect is observed with the increase of degree of substitution. On its turn, the calcite presents better results of rheological and filtration properties with the decrease of average viii particle diameter and increase of particle size distribution. According to all properties evaluated, it has been obvious the interaction of CMC with the minerals (CaCO3 and clay) in the aqueous medium

A resposta metabólica ao trauma cranioencefálico é autolimitada? Análise das proteínas de fase aguda e glicemia

Nos últimos anos tem havido referências à limitação da resposta metabólica nas duas primeiras semanas após trauma cranioencefálico (TCE). Foi feita proposta de estudo a partir de experimento clínico em pacientes com trauma encefálico grave, que foram avaliados por volta de 7 dias após a lesão (M1). A segunda avaliação ocorreu 4 dias após (M2), e a terceira 3 a 4 dias após (M3). em um período de 2 anos, foram selecionados 28 pacientes do sexo masculino, com trauma encefálico grave, escala de gravidade de Glasgow entre 4 e 6. Dentre os 28 pacientes, 6 completaram o estudo proposto. Os pacientes foram acompanhados clinicamente durante toda a fase do experimento. em cada um dos momentos de análise, foram feitas análises da excreção nitrogenada e proteínas de fase aguda. da mesma forma foram feitas determinações da glicemia plasmática, N-amínico e triglicerídeos. Os resultados do estudo demonstraram não haver modificações no balanço nitrogenado, normalização da proteína-C-reativa e redução relativa da glicemia ao final do experimento. Os autores tecem considerações sobre os possíveis mecanismos envolvidos na modulação da resposta metabólica e concluem que o hipermetabolismo, a basear-se na análise da glicemia e das proteínas de fase aguda, não persiste além do 13° dia do período de recuperação pós-trauma. São feitas sugestões de estudos futuros que possam elucidar os mecanismos envolvidos na normalização do hipercatabolismo e hipermetabolismo observados nas duas primeiras semanas após TCE.

Aplicações clínicas da suplementação de L-carnitina

A carnitina, uma amina quaternária (3-hidroxi-4-N-trimetilamino-butirato), é sintetizada no organismo (fígado, rins e cérebro) a partir de dois aminoácidos essenciais: lisina e metionina, exigindo para sua síntese a presença de ferro, ácido ascórbico, niacina e vitamina B6. Tem função fundamental na geração de energia pela célula, pois age nas reações transferidoras de ácidos graxos livres do citosol para mitocôndrias, facilitando sua oxidação e geração de adenosina Trifosfato. A concentração orgânica de carnitina é resultado de processos metabólicos - como ingestão, biossíntese, transporte dentro e fora dos tecidos e excreção - que, quando alterados em função de diversas doenças, levam a um estado carencial de carnitina com prejuízos relacionados ao metabolismo de lipídeos. A suplementação de L-carnitina pode aumentar o fluxo sangüíneo aos músculos devido também ao seu efeito vasodilatador e antioxidante, reduzindo algumas complicações de doenças isquêmicas, como a doença arterial coronariana, e as conseqüências da neuropatia diabética. Por esse motivo, o objetivo do presente trabalho foi descrever possíveis benefícios da suplementação de carnitina nos indivíduos com necessidades especiais e susceptíveis a carências de carnitina, como os portadores de doenças renais, neuropatia diabética, síndrome da imunodefeciência adquirida e doenças cardiovasculares.

Ultrastructure of the urethra of the Mongolian gerbil

Objective: the urethra is the main port of entry of sexually transmitted pathogens. However, papers on the morphology of the urethra are scarce. The Mongolian gerbil is a rodent native of the Mongolia and China and has been utilized as a laboratory animal since the 1960s. This work describes the ultrastructure of the urethra of the Mongolian gerbil to provide data for future experimental studies. Methods: the urethra of ten adult male gerbils was studied by transmission electron microscopy. Results: the epithelium of the pelvic urethra possesses two cell types: I and II, without the formation of cellular layers, while the penile urethra possesses cellular layers: basal, intermediate and superficial. The urethra presents neurosecretory cells belonging to the amine precursor uptake and decarboxylation system. Conclusions: the urethral epithelium of the gerbil is a neurosecretory epithelium, part of the amine precursor uptake and decarboxylation system.

Fotoperíodo, temperatura e reguladores vegetais na germinação de sementes de Passiflora cincinnata Mast.

A espécie Passiflora cincinnata Mast., pertencente à família Passifloraceae, é silvestre e popularmente conhecida como maracujá-do-mato, sendo considerada importante na produção de porta-enxertos, uma vez que é tolerante à seca, a doenças causadas por bactérias e a nematóides, além de poder ser utilizada em programas de melhoramento genético. O trabalho teve como objetivos estudar o efeito da luz e da temperatura e a interação entre temperatura e reguladores vegetais na germinação de sementes de Passiflora cincinnata Mast. Foi constituído de três experimentos: no primeiro, estudou-se o efeito da luz e da temperatura na germinação de sementes; no segundo, o efeito de diferentes concentrações dos reguladores vegetais GA4+7 + N-(fenilmetil)-aminopurina na germinação das sementes e, no terceiro, a interação entre temperatura e reguladores vegetais na germinação das sementes. O delineamento experimental foi inteiramente casualizado para todos os experimentos e os dados foram submetidos à análise de variância e comparação das médias pelo teste Tukey, a 5% de probabilidade. É possível observar que a luz exerce efeito inibitório sobre a germinação das sementes, e que os reguladores vegetais, GA4+7 + N-(fenilmetil)-aminopurina, são eficientes na superação da dormência, além de ampliarem os limites de temperatura da germinação. A temperatura alternada 20-30ºC mostra-se a mais adequada para a germinação de sementes dessa espécie.

Th1/Th2 cytokine production by clove-treated mice

Although clove possesses several biological and therapeutic properties, its immunomodulatory action has not been fully investigated. The goal of this work was to investigate the effect of administration of the water extract of clove over a short-term to BALB/c mice on Th1 (IFN-gamma and IL-2) and Th2 (IL-4 and IL-10) cytokine production. After treatment, spleen cells were aseptically removed and cells were stimulated with concanavalin A. Supernatants of cell cultures were used for cytokine determination by ELISA. The chemical composition of the extract was also carried out, revealing that eugenol(4-allyl-2-methoxyphenol) was the major component in our sample. Although the anti-inflammatory action of clove has been mentioned, our data showed that clove administration to mice did not influence the Th1/Th2 cytokine balance. Further studies dealing with cytokine expression and production will provide a better understanding of clove's immunomodulatory and anti-inflammatory actions, using different extract concentrations and different intake periods.

Protective effects of beta-glucan extracted from Agaricus brasiliensis against chemically induced DNA damage in human lymphocytes

beta-Glucans (BGs) are polysaccharides that are found in the cell walls of organisms such as bacteria, fungi, and some cereals. The objective of the present study was to investigate the genotoxic and antigenotoxic effects of BG extracted from the mushroom Agaricus brasiliensis (=Agaricus blazei Murrill ss. Heinemann). The mutagenic activity of BG was tested in single-cell gel electrophoresis assays with human peripheral lymphocytes. In addition, the protective effects against the cooked food mutagen 3-amino-1-methyl-5H-pyrido[4,3-b]indole (Trp-P-2) and (+/-)-anti-B[a]P-7,8-dihydrodiol-9,10-epoxide (BPDE), which is the main metabolite of B[a]P, and against ROS (H2O2)-induced DNA damage, were studied. The results showed that the compound itself was devoid of mutagenic activity, and that a significant dose-dependent protective effect against damage induced by hydrogen peroxide and Trp-P-2 occurred in the dose range 20-80 mu g/ml. To investigate the prevention of Trp-P-2-induced DNA damage, a binding assay was carried out to determine whether BG inactivates the amine via direct binding. Since no such interactions were observed, it is likely that BG interacts with enzymes involved in the metabolism of the amine.

Treatment of simulated wastewater containing n-phenyl-n-isopropyl-p-phenylenediamine using electrolysis system with Ti/TiRuO2 electrodes

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hydrodechlorination of 1,2-dichloroethane by rhodium catalysts under water gas shift reaction conditions

Homogeneous catalysts prepared from rhodium trichloride in aqueous aromatic amines have been shown to reduce C-CI bonds under mild water gas shift conditions (T=100 degrees C, P-CO = 1.0 atm). In a 4-picoline/water solvent mixture, 1,2-dichloroethane is reduced to ethylene and ethane in yields compatible with the consumption of the reducing agent CO and with the formation of CO2. Variation of the catalyst solutions by using different substituted pyridines shows a pattern of catalytic activity parallel to that reported previously for H-2 production from the shift reaction, There is a moderate dependence of activity on the basicity of the aromatic amine, but a methyl group at the alpha-position exercises a strong negative steric effect. Long term studies show decrease of the activity with the time perhaps due to the build up of chloride in the medium. (C) 1999 Elsevier B.V. B.V. All rights reserved.

Solid-phase peptide synthesis in highly loaded conditions

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)