Mestrado em Química

URI Permanente para esta coleção

http://repositorio.ufes.br/handle/10/17502

Nível: Mestrado Acadêmico
Ano de início: 2006
Conceito atual na CAPES: 5
Ato normativo: Homologação da 85ª Reunião do CTC-ES, Parecer CNE/CES nº 163/2005.
Processo nº 23001.000081/2005-56 do Ministério da Educação.
Publicado no DOU 28/07/2005, seção 1, página 11)
Periodicidade de seleção: Anual
Área(s) de concentração: Química
Url do curso: https://quimica.vitoria.ufes.br/pt-br/pos-graduacao/PPGQ/detalhes-do-curso?id=954

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Estudo fitoquímico do óleo essencial dos frutos da aroeira (Schinus terebinthifolius Raddi) e sua eficácia no combate ao dengue
(Universidade Federal do Espírito Santo, 2008-01-01) Cole, Eduardo Roberto; Santos, Reginaldo Bezerra dos; Oliveira Júnior, Luiz Fernando Ganassali de; Lacerda Júnior, Valdemar; Zarbin, Paulo Henrique Gorgatti
Dengue is considered the most important of the human arbovirosis, constituting nowadays one of the main Public Health problems in the world. The disease is caused by a virus of the genus Flavivirus with four different serotypes, transmitted by mosquitoes of the genus Aedes, and Aedes aegypti its main vector. The control of the vector by synthetic insecticides has been the main procedure adopted in combating the disease, since there are no effective vaccines against the different virus serotypes. The insecticides, although effective, present serious problems related to its use, among which can be highlighted environmental damage, toxicity for human use, and the risk of the selection of resistant larvae and adults. The search for natural and less aggressive insecticide methodologies has considerably grown in the last years, with the use of plant extracts and natural substances. Studies reveal that plant essential oils have many potential biological activities against insects. Schinus terebinthifolius Raddi (Brazilian peppertree) species, well known for its ornamental properties and its use as food condiment, has also been the object of studies of biological activity. In order to provide more information about the chemical identity of the essential oil of the Schinus terebinthifolius fruits and contribute on the discovery of new products to combat dengue, this study aimed to characterize chemically and physical-chemically the essential oil, and also to evaluate its larvicidal , insecticide and repellent activities related to the Aedes aegypti.The results yield of the process of extraction by hydrodistillation (6,54 ± 1,56%) did not present a significant difference between the repetitions. The specific density values (0,9097 ± 0,0200 g/cm3 ), and index of refraction (1,4750 ± 0,0001) of the essential oil showed up close to the available data in the literature, a fact not observed on the specific rotation value (+26,41 ± 0,0200). Thin-Layer Chromatography (TLC) and Gas Chromatography (GC) showed the same chromatographic profile for the samples obtained. The analysis by Gas Chromatography coupled to the Mass Spectrometry (GC/MS) detected 28 volatile substances. Among these, 17 were identified (91,15% of the total identified), among what 12 are monoterpenes and 5 are sesquiterpenes. The predominant chemical species, all monoterpenics were: d-3-carene (30,37%), limonene (17,44%), a-phellandrene (12,60%), a-pinene (12,59%), myrcene (5,82%), and o-cymene (3,46%). The larvicidal, insecticide and repellent activities of the essential oil were highlighted against the Aedes aegypti, being the concentrations 169,20 µg/mL; 50,00 µL and 2,39% (w/w), the most effective, respectively, in each of the tests made. The LC50 obtained was 117,34 µg/mL for the larvicidal test, and 28,80 µL for the insecticide testing.
Estudo da transesterificação metílica do óleo de cutieira (Joannesia princeps Vell.) e da munguba (Pachira aquatica Aulb.) em meio alcalino
(Universidade Federal do Espírito Santo, 2008-03-14) Souza, Tércio da Silva de; Santos, Reginaldo Bezerra dos; Beatriz, Adilson; Lacerda Junior, Valdemar; Castro, Eustaquio Vinicius Ribeiro de
Caracterização e reciclagem eletroquímica dos cátodos exauridos das baterias de íon-Li de telefones celulares
(Universidade Federal do Espírito Santo, 2008-04-01) Garcia, Eric Marsalha; Freitas, Marcos Benedito José Geraldo de; Lelis, Maria de Fátima Fontes; Souza, Ernesto Chaves Pereira de
In this work, a method for electrochemical recycling of cobalt present in cathode of the spent Li-ion batteries has been proposed. The cathodes composition characterized by X-ray diffraction is: LiCoO2, C, Al and Co3O4. With the help of Electrochemistry Quartz Crystal Microbalance (EQCM) investigated the cobalt eletrodeposition mechanism. Was observed that the cobalt electrodeposition occurs by direct mechanism at pH = 5.40. The cobalt eletrodeposition mechanism in pH = 2.70 depends on the applied technique. In potentiodinamic conditions the cobalt electrodepossition occurs by the mechanism of adsorbed hydrogen. In potentiostatic conditions, it verified that the cobalt reduction occurs simultaneously by direct reduction and adsorbed hydrogen mechanism. The cobalt electrodeposition on the Al is strong influenced by pH solution. A maximum charge efficiency to potentiostatic cobalt electrodeposition on Al is obtained in potential equal to -1.00 V so much for pH = 5.40 as for 2.70. Maximum charge efficiency is obtained at pH = 5.40 is equal to 96%. The potentiostatic electrodeposition of cobalt follows the progressive nucleation model in pH = 5.40 and is best described by instantaneous nucleation model in pH = 2.70. The morphology and structure were characterized with help of the Scanning Electronic Microscopy (SEM) and X-Ray Diffraction (DRX) and were correlated with the growth mechanism of the cobalt electrodeposition. The mechanism 3D occurs preferentially in pH = 5.40 and 2D in pH = 2.70 for charge density of 10.0 Ccm-2. The cobalt electrodeposits growth is better described by a simultaneous mechanism 2D and 3D with the charge density increase for 50.0 C cm-2. The charge density of the cobalt electrodissolution depends on the deposit structure and morphology.
Implantação de um sistema de destilação atmosférica de petróleos no LabPetro-UFES e estudos quimiométricos de frações
(Universidade Federal do Espírito Santo, 2008-05-09) Mota, Mariana Frizera Borghi; Castro, Eustáquio Vinicius Ribeiro de; Santos, Reginaldo Bezerra dos; Freitas, Marcos Benedito José Geraldo de; Sena, Denise Rocco de Sena
Síntese, caracterização e estudo do comportamento térmico dos sais de perclorato de lantanídeos (III) com a n-metil-e-caprolactama
(Universidade Federal do Espírito Santo, 2008-06-20) Borges, Alex dos Santos; Silva, Elias Meira da; Morigaki, Milton Koiti; Souza, Aparecido Ribeiro de
Síntese de complexos organometálicos de cobalto (II) e ferro (II) contendo ligante isocianeto
(Universidade Federal do Espírito Santo, 2008-06-27) Pavan, Jamile Rocha; Morigaki, Milton Koiti; Silva, Elias Meira da; Dias, Gilson Herbert Magalhães
In this work there will be presented the preparation of highly colored compounds of the general formula [Co(t-BuNC)nX2], isolated to the low temperature in the reaction of CoX2hydrated (X = Cl, Br and I) with t-BuNC in acetone and under inert atmosphere of argon. The products has been characterized by CHN microanalysis, cobalt analysis by titulation with EDTA, TG/DTG in atmosphere of oxygen, and electrolytic conductivity in acetone. The local symmetry D4h(Eu) has been attributed for the compound with X = I (?(CN) = 2181, 3 cm-1) with based on the spectroscopic analysis in the infrared one. Measure of susceptibility magnetic indicates that the complex is paramagnetic with one unpaired electron. This compound presents a thermal decomposition (TG/DTG) in two stages. The process of decomposition of the products with bromide and chloride was similar to that of an iodide, though his taken place in less temperatures, since they were composed less stable. Finally, the low conductivity in solution proved the nature not eletrolitic of these products.The complex [CoMNT(t-BuNC)2] has been obtained from the equimolar reaction of CoCl2. 2H2O, Na2MNT, and excess of t-BuNC in acetone. The product was identified through elementary analysis (CHN), IR,TG/DTG in atmosphere of oxygen, electrolytic conductivity in acetone and magnetic measure. Two structures are probable: tetrahedral and square planar. The magnetic measure indicated the formation of the square planar structure.This work aims also several?-acids ligands to study the influence of in the chemical stability from the iron. Complexes chelates of formula [Fe(MNT)(LL)(t-BuNC)2] (MNT = S2C2(CN)2; LL = phen or bipi), identified through elementary analysis (CHN), thermogravimetric analysis, infrared spectra and Mössbauer was obtained from the equimolar reaction of FeBr2, Na2MNT, LL and excess of t-BuNC in THF. The infrared spectra in the region of the ?(CN) presented three absorption around 2189, 2130 and 2090 cm-1. The higher frequency is attributed to ?(CN) of the chelate MNT and two lower band are attributed to ?(CN) of the isocyanide. Two structures are probable: cis (C1) and trans (C2v) relative to an isocyanide, which they are indistinguishable for the infrared one because of presenting the same activity for ?(CN). The Mössbauer parameters indicate an xvincrease of the ?-back donation in the atom from iron and an environment octahedral distorted relatively to the FeBr2precursor. The thermogram of the adducts support the results of the elementary analyses and indicate a more thermal stability for the derivate of bipyridine (decomposition to 138.9°C), regarding the derivate o-phenantroline (109.5°C). The synthesis of these complexes was of abridgement importance, because it allowed to correlate data vibration and nuclear property, besides supplying important information on the nature of the iron atom bond.
Caracterização química inorgânica de rejeitos segregados de serragem de rochas ornamentais do Espírito Santo
(Universidade Federal do Espírito Santo, 2008-08-08) Freitas, José Júlio Garcia de; Jesus, Honério Coutinho de; Lima, Maria Tereza Weitzel Dias Carneiro; Neves, Mirna Aparecida; Barreto Neto, Aurélio Azevedo
Industrial wastes of ornamental rocks are in prominence due to the enormous environmental impact generated as result of the large volumes of material generated from sawdust of rock blocks. In waste management, the characterization stage is important and that guides attitudes to be taken in the destination. The present work whished an inorganic chemical characterization of residue from ornamental stones sector sawdust, sampling from a segregated, which was the collection of samples directly at the disposal of sawdust looms, after the hydrocyclone of it and before being mixed in the tank sewage. For each sample collected were obtained in the laboratory values of pH analysis, moisture content, solid content of wet and dry. The samples were subjected to tests of solubilization and leaching, as the series of standards methods for solid waste NBR 10,004, 10,005, 10,006 and 10,007, both from 2004, by ABNT. The segregated wastes were also subjected to the test for total dissolution for determination of some metals of interest. The extracts generated in the test for leaching, solubilization and total dissolution were analyzed by the technique of atomic absorption (F-AAS and GF-AAS) for determination of some metals of interest. For some samples was performed the analysis X-ray diffraction to research the mineralogical composition of the material segregated, and generate possible correlations with the extracts obtained after solubilization and leaching test. There were also conducted some thermal analysis (TG and DTG) with the aim of evaluating possible interactions of the materials inputs used with the powder of some of the rocks sawn. For wastes there was the possibility of forecasting the volume of sludge generated by the abrasive size of the quantity of materials used and volume of rock processed. The process of cutting granite presented uniform water consumption (44,3% ± 6,0), however it was more expensive than the same process for marbles because of the higher consumption of input materials related to the greater hardness of the granite. The TG and DTG showed consistent results on the amount of input CaO during the process of sawing, representing (0,5-1,2)% of the samples. A great solubilization of these metals was found through good correlations obtained between total Cr and Al in terms of the high pH values of the original samples. It was proved through the X-ray diffraction, the presence of Al in major mineral components of rocks and the reason for the dark tone (biotite) from some mother- ix generating rock samples PSG, PF, PA and VP. This efficiency was not repeated in investigating the possible generator of Cr soluble minerals in the samples ASF, AI and ASC. For the material carbonates, it was confirmed in the diffraction graph, the presence of Ca,MgCO3, CaMg(CO3)2 and CaCO3. Through pH analysis and metals determination (Na, Cr, Al, Cd, Pb, Mn, Zn, Fe, Cu, Ca and As) by the technique of atomic absorption in the extracts obtained, it could be classified as dangerous samples (Class I) (pH> 12.5) (ASF, AI, PA, OITA, ASC and JG) Class II (not dangerous and not inert) (CA and PSG) and Class B (not dangerous but inert) (CC, GN, PVC, BR, MBC and SMO).
Estudo da degradação de hidrocarbonetos policíclicos aromáticos a partir da reação de fenton utilizando magnetitas dopadas com cobalto
(Universidade Federal do Espírito Santo, 2009-03-06) Biazati, Luciana Brunhara; Rodrigues Neto, Renato; Lelis, Maria de Fatima Fontes; Sena, Denise Rocco de; Castro, Eustáquio Vinicius Ribeiro de
The awareness regarding Polycyclics Aromatic Hydrocarbons (PAHs), petroleum derivatives, has been increasing over the years due to their toxic, carcinogenic and mutagenic characteristics. The increase on the use of petroleum and its derivatives as energy source has induced many accidents spilling liquid effluent in the environment, making harm to biota, including human beings. So that, developing efficient procedures is important on the partial or total elimination of these compounds. A common technique that has been used recently is the Fenton process. This is based on the generation of hydroxyl radical from the reaction of Fe2+ions and hydrogen peroxyde, forming CO2, H2O and inorganic ions from heteroatoms. This study evaluated PAHs (acenaphthene, fluorene, fluoranthene, benzo(a)pyrene) decomposition due to the fenton process in water by utilization of pure and doped magnetites (with Co as source of ions Fe2+) and hydrogen peroxyde. In order to compare the two kinds of magnetites, fluorene was degraded utilizing fluorescence to evaluate its concentration. We observed that reaction was not significant when pure magnetite was used, whereas doped one degraded fluorene completely after five hours. Because of this, only doped magnetite was used with the other compounds, but evaluating its efficience and intermadiaries formation by gas chromatography and mass spectrometry (GC/MS). The degradation of HPAs varied from 39 to 100%. Acenaphtene (with three rings) reacted more intensively whereas benzo(a)pyrene (with five) reacted less. No intermediate compounds were found above the detection limit. Beside GC-MS, fluorescence was utilized to analyse the compounds. Our goal was to compare the pure magnetite efficiency to that of doped one regarding fluorene degradation. We observed that the degradation using the former was not significant. Magnitite doped with cobalt degraded it within five hours. So, the method may be a new alternative of treating liquid efluents
Estudo dos filmes de poliacrilonitrila modificados pela adição de clorofilas, citocromo-c, Fe(II) e Fe(III)
(Universidade Federal do Espírito Santo, 2009-03-25) Santos, Vadilson Malaquias dos; Silva Filho, Eloi Alves da; Sena, Geovane Lopes de; Brocchi, Eduardo de Albuquerque
In this work was studiedthe synthesis, characterization and some properties of the films of polyacrylonitrile (PAN), when adsorbed organic charge of metalporphyrinsnatural, organic molecules in the specific case of well known chemical properties, the chlorophyll (Chl) and cytochrome c (Cyt-c) and inorganiccharges: salts of Fe (II), Fe (III) and K +. In experiments to obtain data, wereused the techniques of infrared spectroscopy (FTIR) in the ultraviolet-visible (UV-VIS), fluorescence (EF), Mössbauer (MS), X-ray diffraction (XRD), microscopy scanning electron (SEM), thermal analysis (TG and DSC), elemental analysis, viscometer, cyclic voltammetry, and measures of resistivity. The synthesis of PAN in four replicates showed a yield above 77%.The molecular weight of PAN was obtained through the viscometer and the degree of crystallinity was obtained by XRD, are comparable to the literature. In the adsorption of cytochrome c, chlorophyll, and salts of Fe (II), Fe (III) and K+were products with characteristics that were analyzed by FTIR, TG, DSC, UV-VIS and EF, which has significant changes in physical and chemical properties of these materials. Besides the analysis of conventional Mössbauer analysis were carried out and measures the conductivity of materials. The adsorption isotherms and kinetics were performed for the salts of Fe (III) and cytochrome c show results of the adsorption of these substances in the PAN
Estudos de uma série de desemulsificantes e seus efeitos sobre a reologia de um tipo de óleo pesado
(Universidade Federal do Espírito Santo, 2009-03-27) Bragança, Carlos; Castro, Eustáquio Vinicius Ribeiro de; Pereira, Rita de Cássia Campos; Sena, Geovane Lopes de
At petroleum industry, the formation and stability of emulsions of the type oil / water can trigger a series of problems ranging from production to refining. The main problems, caused by the presence of water are related to the processes of corrosion and stabilization of salts that can damage pipes and "poison" catalysts used in refining. Quantification of water in oil can be made by the Karl Fischer method, by dehydration or by the method of BSW (ASTM D4007). In the latter, used chemicals that act as demulsifiers, which may have greater or lesser power to "break" the emulsion, depending on the characteristics of the system. The withdrawal of water in oil (primary processing) may be made by physical processes such as electrostatic precipitation or by the use of chemical demulsifiers. However, little is known about the effect of such products in the production process, such as rheological factors, responsible for transporting the products from the place of production up to refining. In this work, it was studied the effectiveness of a series of demulsifiers on the stability of emulsions heavy oil / water solutions and the effects of solvents / demulsifiers on the rheology of a heavy oil with the objective of selecting the best product for use in both BSW tests as primary processing.
Ressonância magnética nuclear de baixo campo em estudos de petróleos
(Universidade Federal do Espírito Santo, 2009-05-29) Silva, Renzo Corrêa; Castro, Eustáquio Vinicius Ribeiro de; Menezes, Sonia Maria Cabral de; Lacerda Junior, Valdemar; Freitas, Jair Carlos Checon de
In some Nuclear Magnetic Resonance (NMR) applications the search for instruments capable of generating more intense magnetic fields is not necessary, turning the scientists to the development of low-field NMR equipments, typically of the benchtop kind: cheaper, lighter, with industrial appeal and suitable for on-line use. In the petroleum industry low-field NMR data are commonly used for in situ evaluations of petroleum formations (NMR logging), or to analyze rocks and fluids, on benchtop instruments at petrophysical laboratories. In this work, the potential of using benchtop low-field NMR instruments for analysis of mixtures involving crude oils and water was investigated. Experimental measurements were executed by means of the CPMG pulse sequence for T2 determination, and these data were used to obtain T2distribution curves by the Inverse Laplace Transformation. The instrument ability of quantifying water and petroleum in biphasic mixtures, by different methodologies, was tested. For deionized water and petroleum mixtures one achieved excellent results, with RMSECV (root mean squared error of cross-validation) of 0.8% for a regression between the water content (wt.%) and the relative area of the water peak in the T2 distribution curve, or a standard deviation of 0.9% for a relationship between the water content and the relative water peak area, corrected by the relative hydrogen index of the crude. In the case of biphasic mixtures of water doped with relaxing agent and crude oils, the best result of RMSECV=1.6% was achieved by using the raw magnetization decay data for a PLS regression. A related investigation involved the search for component quantification in crude oil blends; in this case, several mixtures of two distinct crude oils (with very different viscosities) were prepared. The quantification of each component in the mixture was accomplished with RMSECV=1.2% by using the T2 distribution curves for PLS regression. Three-component petroleum blends were also analyzed, being two of them very similar. A PLS model with 8 latent variables built from the T2 distribution data gave the RMSECV values of 4.1, 0.9 and 4.6% for the quantification of each oil component, showing the promising potential of the method for the study of more complex petroleum blends.
Formação e caracterização de eletrodepósitos de cobre, cobalto-cobre e multicamadas cobalto-cobre a partir de baterias de íon-Li exauridas
(Universidade Federal do Espírito Santo, 2009-06-08) Celante, Vinicius Guilherme; Freitas, Marcos Benedito José Geraldo de; Mascaro, Lucia Helena; Lelis, Maria de Fátima Fontes
In this work the processes of formation and characterization of electrodeposits of copper, Cu and Co-Co-Cu multilayer from the recycling of exhausted batteries to Li-ion were studied. For the electrodeposition of copper, the charge efficiency is obtained in the range 3.0 to 5.0 C cm-2, with about 98.0% at pH values of 2.0 and 4.5. For measures of EQCM for copper, there is a simultaneous mechanism between the direct deposition and reduction from Cu+. In both conditions of pH, the presence of Cu2O is caused by alkalinization of the interface electrode/solution. The equivalent circuit of the system, obtained by EIS resulted in Rs(RpQ)W. The presence of diffusional element W is on the diffusion of H+ ions from solution to the pores of the electrodeposits. The constant phase element is associated with the surface heterogeneity. The SEM measures resulted in the areas of micro and macroporosity. EDS analysis observed that the surface is composed mostly of copper. Measures of XRD at pH = 2.0 and 4.5 resulted in the directions [111] and [200], related to FCC structure of metallic copper, with the presence of the direction [002] of Cu2O. With the increase of the charge density, there is a decrease in the relative intensity peaks of metallic copper and the detection of the direction [110] also related to Cu2O. The electrodeposition of Co-Cu resulted in a mechanism of deposition of Co with formation of Co(OH)2 and copper in the presence of Cu+. The equivalent circuit obtained was Rs(RpQ)W, with W on the diffusion of H+ions from bulk phase to the interface metal/electrode. The characterization by SEM resulted in microporous electrodeposits at pH = 2.7 and microporosity and perpendicular growth to the substrate at pH = 5.4. For the technique of EDS, there was a quantity of Co and Cu approximately 2 times greater on the surface at pH = 2.7 than at pH = 5.4. The crystallographic directions obtained by XRD show both the copper and cobalt preferably electrodeposits on the FCC structure. The Co-Cu multilayers were studied on different substrates (Al, Pt and GC). Measures of EIS presented an inductor L in the equivalent circuit Rs(RpQ)L, related to the dissolution of the cobalt deposit. Measures of SEM, EDS and XRD showed that at pH = 2.7 the electrodeposits occur preferentially by 2D growth with higher coating and at pH = 5.4 a simultaneous 2D and 3D growth, with areas of micro and macroporosity. The deposits are mostly formed by Co and Cu, and detected the substrate of Al. Both copper and cobalt are deposited on FCC structure.
Síntese, dopagem e caracterização da polianilina com sais de Fe (II) e Fe (III)
(Universidade Federal do Espírito Santo, 2009-06-10) Fornazier Filho, Yonis; Nunes Filho, Evaristo; Silva Filho, Eloi Alves da; Sena, Geovane Lopes de; Souza Júnior, Fernando Gomes de
In present work, the synthesis and characterization of polyaniline has been done. The Polyaniline was prepared using aniline and (NH4)2S2O8 in acid medium at 0°C. A polymer solid was obtained yield was equal 60.4% and with molecular weight of 246.13 kg/mol, determined by the technique of viscosity. The synthesized polymer was added salts of Fe (II) and Fe (III), to study the changes in their structural properties, thermals and the conductivity. The samples were studied by techniques of elemental analysis, infrared spectroscopy (FTIR) in the Ultraviolet-Visible (UV-VIS) and Mössbauer, X-ray diffraction, SEM, EDS, Thermal Analysis (TG and DSC), and measures to of solutions of polyaniline conductivity and resistivity under pressure of solid polymer samples. The experimental results using these techniques showed that the ions Fe (II) interact with the benzenoids nitrogen supported by data from Mössbauer and resistivity, and thus can be suggested is that the formation of a complex Pani-Fe (II). Furthermore, the ions Fe (III) added to Polyaniline showed no significant interaction with the polymer chain. Therefore, it was observed that it is possible the interaction of ions Fe (II) and Fe (III) with polyaniline as esmeraldine salt, and kept its conductive properties. ix
Degradação de compostos aromáticos presentes em água produzida através de sistema Fenton heterogêneo utilizando óxidos de ferro natural e sintético
(Universidade Federal do Espírito Santo, 2009-07-03) Pereira, Júlia Raquel Peterle; Lelis, Maria de Fátima Fontes; Sena, Denise Rocco de; Castro, Eustáquio Vinícius Ribeiro de
The water produced (AP) is the wastewater of the oil industry that stands out for being the by-product generated in greater quantity and for its high toxic potential. Environmental risks associated with the AP may vary depending on their composition, and before being discarded or reused it must receive effective treatments to fit in the existing legislation, according to the destination that it will be given. This work aimed to propose a treatment in the Jubarte AP-ES field aiming the reduction of aromatic compounds through photo-Fenton and Fenton heterogeneous using synthetic magnetite doped with titanium and a clay soil rich in iron, collected in the Greater Vitória-ES Region, to replace the soluble iron, with the main objective of minimizing the generation of sludge. The magnetite with different degrees of substitution by isomorphic titanium were characterized by chemical analyses (Fe 2+, Fe3+, Ti 4+), X-ray diffraction and Mössbauer spectroscopy, while the soil was characterized by chemical analysis, size, X-ray diffraction and Mössbauer spectroscopy. The AP was characterized by: pH, conductivity, salinity, turbidity, total phenols and aromatic compounds by scanning spectrophotometry in ultraviolet (UV). The results showed that the increase of Ti4 + in the structure of magnetite increases the catalytic activity of the material. Preliminary tests showed that the presence of salt inhibits the reaction of Fenton and photo-Fenton. The process proved to be quite effective, resulting in significant removals of 92.5% for phenolic compounds using photo-Fenton reaction with titanomagnetita the degree of doping with titanium and 78% using photo-Fenton reaction with the clay soil after 60 minutes of reaction. The intensity of UV spectra of AP decreased significantly, indicating qualitatively the reduction of aromatic compounds by heterogeneous Fenton reaction.
Avaliação de diferentes métodos de cálculo de propriedades magnéticas na atribuição inequívoca dos sinais de RMN e da estereoquímica relativa do a-epoxipineno e da 1,6-epoxicarvona
(Universidade Federal do Espírito Santo, 2009-08-27) Queiroz Júnior, Luiz Henrique Keng; Lacerda Junior, Valdemar; Castro, Eustaquio Vinicius Ribeiro de; Santos, Reginaldo Bezerra dos; Oliveira, Kleber Thiago de
The work discussed here aims to use theoretical calculations of the shielding tensors (?)and spin-spin couplingconstants(J)through different theoretical methods(GIAO, CSGT, IGAIM and SGO), in order to make a comparative study of the methods in question, and use the data obtained through these as an auxiliary tool to allow an unequivocalassignment ofboth allof 1H andof 13C NMR signals andthe relative stereochemistry of epoxides.This study focusesontwo compounds, ?-epoxypinene and 1,6-epoxycarvone, characterized by having an oxirane ring, one of the most versatile functional groups within organic chemistry. Compounds of this group are often used as intermediates in the synthesis of natural products, which brings out the importance on studiesof substances belonging to this class.After being arranged in tables, a statistical work was done in order to correlate the experimental data with the theoretical. By examining the standard deviation (SD), mean deviation (MD),linear correlation coefficient (R) and subtleties, that is, some very divergent values between the cisand transisomer, it was possible to assign unequivocallythe 1H and13C NMR signals, and the transstereochemistry for the ?-epoxypinene andthe 1,6-epoxycarvone. It was found that the theoretical values of the NMR chemical shifts obtained with the DFT/B3LYP theory level and CSGT and IGAIM methods applied to calculate the 1H and13C NMRshielding tensors (chemical shifts) of these compounds allow anexcellent correlation with experimental values, and let us associate a low computational cost with ahigh accuracy of the results found.
"Atribuição inequívoca dos sinais de RMN e da estereoquímica relativa de compostos rígidos tipo 'gaiola' (cage-like) : estudo experimental e teórico"
(Universidade Federal do Espírito Santo, 2009-09-18) Salles, Roberta Chechetto; Lacerda Junior, Valdemar; Cunha Neto, Álvaro; Camara, Celso de Amorim; Santos, Reginaldo Bezerra dos
In this work the Nuclear Magnetic Ressonance (NMR) technique was used for the unequivocal attribution of the 1H and 13C{1H} NMR signals from one-dimensional (1H NMR, 13C NMR and DEPT-135) and bidimensional (COSY, HMBC, HSQC and NOESY) experiments. The six analyzed compounds were tricyclo[6.2.1.02,7]undeca-4,9-diene-3,6-dione (3), tricyclo[6.2.1.02,7]undec-9-eno-3,6-dione (20), rel- (6S)-6-hidroxytricyclo[6.2.1.02,7]undec-9-en-3-one (21), rel-(1R, 6S, 7R, 2S, 8S)-3-Oxo-6-(3,4,5-trimethoxyfenilcarbonnyloxi)tricyclo[6.2.1.02,7]undec-9-ene (22), rel-(1S, 2S, 6S, 8S, 7R, 9R)-6,9-epoxytricyclo[6.2.1.02,7]undecan-3-one (23), rel- (2S, 4S, 6S, 10S, 1R, 9R)-10-bromine-6,9-epoxitricyclo[6.2.1.02,7]undecan-3-one (24) were obtained from the adduct obtained from the Diels-Alder reaction between cyclopentadiene and p-benzoquinone. This study focused on cage-like compounds which are known for being biologically active, being amantadine the first and most known bioactive cage-like compound. All chemical shift values were attributed despite the difficulty found due to signals overlapping. When possible, the spin-spin coupling constants (J) were also attributed. The distinction between the bridge hydrogens, for the majority of the compounds, was done by the analysis of the 2D NOESY NMR spectrum. The data obtained from the experimental attribution of the 1H and 13C NMR chemical shift and spin-spin coupling values (J) were compared with theoretical data obtained from computational calculations. The mean deviation (MD), standard deviation (SD) and the linear correlation coefficient (R) values were analyzed for the endo and exo adducts in order to evaluate if the B3LYP/cc-pVTZ model presented good results in shielding tensors (d) and spin-spin coupling constants (J) calculations. Analyzing the results obtained from the theoretical calculations it was observed that, for the chemical shift values the model used presented good results, however, for the calculations of the coupling constants the model did not present satisfactory results
Emprego de espectrometria no infravermelho e métodos quimiométricos para a identificação e quantificação de petróleos a partir de misturas de frações de diesel
(Universidade Federal do Espírito Santo, 2009-09-25) Rocha, Júlia Tristão do Carmo; Castro, Eustáquio Vinicius Ribeiro de; Santos, Reginaldo Bezerra dos; Sena, Denise Rocco de; Morigaki, Milton Koiti
The knowledge of the petroleum`s composition and its products is an essential necessity in a refinery for the adjustment of the process conditions. The infrared spectrometry, associated to chemometrics tools, has been presented as a useful tool to take care of this necessity for its great potentiality and applications. In such a way, due to applicability of the chemometrics tools, in this work the discrimination for PCA (principal components analysis) and the quantification for intervals partial least square (iPLS), for sinergism of intervals (siPLS) and for principal components regression (PCR) of three fractions of destillation are proposals, proceeding from three different petroleums (A, B and C), in the band of diesel attainment (210ºC 260º C approximately) from the absorption in the medium infrared (MIR). For that, 150 mixtures of the 3 fractions were produced, varying it enters 0 and 1,33% between a sample and another one. Later, specters were gotten, in the region of the MIR, of all the produced mixtures and after that the data were submitted to the chemometrics analyses. 100 samples were used for the calibration of model and 50 for its validation. First it was carried through the analysis for principal components and from it it was possible to discriminate the samples in accordance with its predominant fraction. xiAfter the identification of the samples, it was continued in the attempt of if quantifying the 3 fractions, individually and simultaneously, in each one of them through the application of the methods iPLS, siPLS and PCR. The gotten models had been, then, evaluated for its the R2, the RMSEP and the number of latent variable (VL) or principal components (PC) used. iPLS, siPLS and PCR models were also developed for the determination of the samples density and viscosity, which were evaluated in the same way. All the generated models had gotten resulted sufficiently satisfactory. However comparing the models siPLS and iPLS, it was verified that it did not have significant difference between them not justifying, therefore, the use of the models siPLS. About the models generated for PCR, the same ones had also gotten resulted sufficiently next to supplied for the method iPLS not having a justifiable preference in the choice between a method and another one. With this, it demonstrates, therefore, that it is possible to discriminate and to quantify petroleums of distinct origins from its fractions using spectrometry in the region of the MIR and chemometrics techniques
Avaliação de metais-traço no sedimento do sistema estuarino dos rios Piraquê-Açu e Piraquê-Mirim (Aracruz-ES)
(Universidade Federal do Espírito Santo, 2009-12-08) Souza, Max José Belo de; Jesus, Honério Coutinho de; Malm, Olaf; Lelis, Maria de Fátima Fontes; Ribeiro, Araceli Verónica Flores Nardy
It has been determined the Acid Volatile Sulfide(AVS)distribution, Simultaneously Extracted Metals(SEM),some physical-chemical parameters, (oxidation reduction potential, temperature and dissolved oxygen) and organic matterinto the mangrovesediment of the Piraquê-açuand Piraquê-mirim rivers in the district of Santa Cruz(Aracruz –ES). To the AVS and SEM (Cd, Cu, Pb, Ni and Zn) extracted from the sample with cloridricacid 6 mol/L,the Equilibrium Partitioning Modeland comparison with the Lowest Effect Level(LEL),the Probable Effect Level(PEL),the Dutch List,the German List,the CONAMA nº 344 andCETESB(2005)has been applied. Yet the SEM and the values Jesuset al. (2009) reported have been applied, to calculate the Geoaccumulation Index(lgeo),the Enrichment Factor (EF) and to the comparison with values reported from other regions of Brazil.The results found from pH, EH, temperature, DO, AVSandorganic matter appear into the expected values to the estuarine systems. The SEMare below national and internationalvalues (LEL,PEL, Dutch List,German List,CONAMA nº 344 and CETESB) and other regions ofBrazil. The usage of the Equilibrium Partitioning Modelsuggests the non bioavailability of metals. The analyses onto the lgeo and the EF classify the estuarinesystem as not having antropic influence.Results show a low antropic impactof the surrounding communitiesand the estuarine system appears with no environment contamination as the acquired values refer to natural processes of the estuary itself
Síntese, caracterização e estudos termoanalíticos dos cloroacetatos de lantanídeos (III) com a 2-piperidinona
(Universidade Federal do Espírito Santo, 2010-02-23) Motta, Marcus Vinícius Lisboa; Silva, Elias Meira da; Silva, Ademir Oliveira da; Morigaki, Milton Koiti
This work was carried out the synthesis, characterization and studies thermoanalyticalofthe complexesofchloroacetates of the lanthanides (III) with the 2-piperidinone.The complexes were characterized and analyzedby complexometric titration with EDTA, elemental analysis, molecular conductivity, in the infrared spectroscopydata, in the visible absorption spectroof neodymium compound and thermal analysis (TG/DTG e DSC) for all compounds.The compounds are crystalline solids and slightly, soluble in water and dimethylformamide. Conductance measurements in the dimethylformamide indicate a non-eletrolytes behaviour.Infrared spectra showed shifts to lower frequencies of ?CO plus?assCOO. According to theshifts and splitting observed in the Infrared spectrawesuggest that the lactam isbonded through the carbonyl oxygen.The Oscilater Power from the electronic absorption of the solution neodymium compound, indicate poor interaction betweenelectronic transitions: 4I9/2? 2G7/2, 2G5/2 and 4I9/2? 2P1/2of the neodymium ion and dimethylformamide.Thermogravimetric curves (TG / DTG) reported that the complex when heated, undergo fusion without decomposition, except for the complex of neodymium, which presents decomposition during the fusion. The profile of the thermal decomposition of these complexes can be divided into two steps for all the complexes. Peaks have been observed in the DSC curves, with features endothermic and exothermic, related to the merger and decomposition of the complex
Otimização de rotina analítica para elementos traços em sedimento de lagoa por ICP-OES : Lagoa Juara-Serra/ES
(Universidade Federal do Espírito Santo, 2010-02-26) Oliveira, Antonio Carlos de; Braga, Florindo dos Santos; Lelis, Maria de Fátima Fontes; Silva, Ademir Oliveira da; Castro, Eustáquio Vinícius Ribeiro de
This workevaluates the application of the technique of ICP-OES for the determination of trace elements that are environmentally viable in sediment samples from the lake. We investigated the elements As, Ba, Cd, Co, Cr, Cu, Mn, Mo, Ni, Pb, Se, Sr and Zn and Al as a majority element, all measured in the fraction less than 63µm sediment dried at 40°C using a spectrometer in view radial, V-groove nebulizer, a mist chamber Sturman-Master and detection system based on coupled device (CCD). We investigated the robustness of the plasma, pumping speed, pressure in the mist chamber, the power of radio frequency, integration time of the signal. Under optimum conditions was obtained limits of detection (LD)and the limits of quantification ( LQ).Although the present and if the higher LQ's yet these are below the guides Threshold Effects Levels (TEL) and Probable Effects Levels (PEL) established by the Canadian Council of Ministers of the Environment (CCME), which is a reference to the resolution of the National Council on Environment (CONAMA 344). The methodology was developed through the use of Certified Reference Material (CRM) MESS 3 marine sediment, resulting in concentrations consistent with the certified (relative error <10%), except for Al, As and Cd showed relative error on the throne of 12 %. The quality of the results was evaluated considering also the precision (RSD <10%) with As, Cd, Pb and Se only slightly higher than desired, and removal of duplicates that tests showed satisfactory results for all trace elements studied.The sediment of Lake Juara -Serra / ES was characterized by determination of Total Organic Matter (TOM) using the techniques of the oven at 550ºC and thermogravimetric analysis (TA). The result of TOM by heating in a furnace results showed two times higher than that obtained by the derivative of the TA curve. The result of trace elements in sediment and TOM were correlated with turbidity and pH of surface water by Principal Component Analysis (PCA) getting to know the positive and negative correlations between groups of parameters. Observed four groups of parameters positively correlated: Pb, Ni, Ba, Cu, Mo and turbidity; Zn, Cr and Al; Co, Se,As and pH; Sr, Cd and TOM. The group of Cd and Zn were negatively correlated, possibly due to anthropogenic contribution. The Cd that had values above the TEL but belowthe PEL

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