Thesis (M.S.)--University of Wisconsin--Madison, 1959. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 18-19).

Thesis (Ph. D.)--Princeton University, 1933.

Thesis--University of Florida. / Description based on print version record. Manuscript copy. Vita. Bibliography: leaves 110-114.

Thesis (Ph. D.)--University of Wisconsin--Madison, 1939. / Typescript. Includes abstract and vita. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 46-47).

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Orientador: Jaime Aparecido Cury / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-12T05:42:46Z (GMT). No. of bitstreams: 1 Tagawa_PriscillaTorres_M.pdf: 350123 bytes, checksum: 1aecd618261e28a6aea2f1f85ef66185 (MD5) Previous issue date: 2008 / Resumo: Indústrias de fertilizantes são consideradas as principais poluidoras do ambiente por fluoreto (F) e o complexo industrial do município de Cubatão, SP, Brasil, é importante produtor de fertilizantes. Assim, os objetivos deste trabalho foram avaliar a poluição local por F no período de 1996 a 2006 (capítulo I dessa tese) e sua sazonalidade no período de 2006-2007 (capítulo II), utilizando a vegetação urbana como biomarcador. Folhas de Terminalia catappa (popularmente conhecida por Chapéu-de-sol ou Amendoeira da praia), localizadas na região industrial ao redor de fábricas de fertilizantes (n=8), de outras indústrias (n=4) e na área urbana municipal (n=4), foram coletadas na primavera de 1996 e 2006 e ao final das quatro estações durante 2006 a 2007. As folhas foram desidratadas, pulverizadas e F extraído com água foi analisado com eletrodo específico. Os resultados do capítulo I mostraram que a concentração de F na vegetação ao redor das indústrias de fertilizantes foi maior (p < 0,05) que aquela encontrada na zona urbana e não mostrou redução de 1996 a 2006 (p > 0,05). Os resultados do capítulo II mostraram que a concentração de F nas folhas das árvores localizadas ao redor das indústrias de fertilizantes foi maior (p < 0,05) que a encontrada próxima das indústrias não produtoras de adubo ou na zona urbana, não havendo diferença significativa entre essas regiões (p > 0,05). O efeito das estações do ano na concentração de fluoreto nas folhas não foi significativo (p = 0,051) e não foi encontrada correlação entre a concentração de F nas folhas e produção de adubos (p > 0,05). Utilizando folhas de Chapéu-de-sol como biomarcador da poluição por F, conclui-se que não houve nos últimos dez anos redução dessa poluição em Cubatão, essa se concentra ao redor das fábricas de fertilizantes, porém parece não haver relação com a produção sazonal de adubos para a agricultura. / Abstract: Fertilizer industries are considered the main environmental polluting of fluoride (F) and the industrial complex of the city of Cubatão, SP, Brazil, is important fertilizer producer. Thus, this study aimed to evaluate the local pollution for F in the period of 1996 to 2006 (chapter I of this thesis) and its seasonality during 2006-2007 (chapter II), using the urban vegetation as biomarker. Leaves of Terminalia catappa (popularly known for Hat-of-sun or Almond tree of the beach), located in the industrial region around of plants of fertilizers (n=8) and other industries (n=4) and in the municipal urban area (n=4), were collected in the springs of 1996 and 2006, and to the end of the four stations during 2006-2007. The leaves were dehydrated, powdered and F extracted with water was analyzed with specific electrode. The results of chapter I showed that the concentration of F in the vegetation around the fertilizer industries was higher that that found in the urban zone and it did not change from 1996 to 2006 (p > 0.05). The results of the chapter II showed that the concentration of F in Terminalia catappa leaves located around the fertilizers industries was higher than those found in the trees located adjacent other industries or in urban area, which did not differ statistically (p > 0.05). The effect of the seasons of the year in the concentration of F in the leaves was not statistically significant (p = 0.051) and was not found correlation between the concentration of F in leaves and fertilizers production (p > 0.05). Using Terminalia catappa leaves as biomarker of industrial pollution by F, it was concluded that the pollution by F in Cubatão did not change in last the ten years, it is concentrated around of the fertilizer industries but its relationship with the seasonal production of fertilizers was not shown. / Mestrado / Odontologia em Saude Coletiva / Mestre em Odontologia em Saúde Coletiva

The high anode overvoltage exhibited by fluorine cells has been variously attributed to bubble overvoltage and to inhibition of the electron transfer process by a layer of insulating carbon fluoride on the surface of the electrode. This thesis presents the results of various experiments which attempt to assess the contribution of the carbon fluoride film to the anode overvoltage in the absence of bubble overvoltage. Fluorine evolution from the molten salt KF.2HF at 85°C was studied at vertical carbon anodes. The techniques employed to study the kinetics and mechanism of this reaction included cyclic voltammetry, steady state potentiostatic polarisation, A.C. impedance, potential pulse and constant current electrolysis. Such measurements indicated that several types of carbon fluoride can be produced on the anode evolving fluorine, depending on the potential of electrolysis. These measurements also show the difficulty in obtaining kinetic parameters for the fluorine evolution reaction. The nature of the fluoride film produced on the carbon anode was investigated using XPS and SIMS analysis of electrodes polarised in the KF.2HF melt at 5V and 9V. These measurements indicated that the film is not one single carbon fluoride but more of a graded nature becoming more heavily fluorinated at higher potentials. The inhibiting effect of the solid film was studied by transfering carbon electrodes, following fluorine evolution in the KF.2HF melt under well' defined conditions, to other electrochemical systems using aqueous or organic electrolytes at room temperature, where electrode kinetic studies were made of redox reactions. Kinetic data were compared with those obtained with unfluorinated carbon surfaces. Observations obtained by the above methods have been related to estimates of the thickness of the carbon fluoride film as determined by measurements of the double layer capacitance in the KF.2HF melt and in other solvent systems. Both capacitance measurements and kinetic studies of redox reactions indicate that the film became progressively thicker as the potential of the fluorine anode was raised. Rates of redox reactions fell by at least two orders of magnitude in the presence of a film formed by polarising the carbon at 6.0V in the KF.2HF melt. Attempts were made to overcome the inhibiting effect of the fluoride films by incorporating transition metals in the carbon anodes. The last section of this thesis explains the manufacture of doped carbon samples and presents results obtained in the KF.2HF melt using such anode materials.

The importance of fluorine in a wide array of different areas within chemistry and biochemistry has been demonstrated time and time again. Fluorine-containing products range from essential substituents in pharmaceuticals and relatively long-lived tracers for PET imagining, to fluoropolymers with outstanding properties, to essential components in most of the strongest acids available to chemists today. Fluorine’s extreme electronegativity makes it a truly unique element, but its acute toxicity in its elemental F2 form makes it difficult to handle, prompting researchers to explore different options for incorporating this important element into a variety of different molecular scaffolds. Due to the remarkable thermodynamic and kinetic stabilities of C-F bonds, methods for forming and breaking these cleanly, and under relatively mild conditions, are in high demand. Fortunately, transition metals have greatly aided in this process. However, fluoroorganometallic chemistry is much less developed than transition metal chemistry involving hydrocarbons, and certainly less understood. One of the primary reasons for this relative dearth of fluoroorganometallic complexes is the difficulty associated with their synthesis. In this work, important steps towards perfluoroalkyl chain-growth within the coordination sphere of a transition metal will be presented, stemming in part from the synthesis and characterization of novel cobalt fluoride and bis(perfluoroalkyl) complexes. As important electrophiles, fluoroalkenes have primarily been used as monomers for the formation of important fluoropolymers. However, their direct reactivity with organics remains rare and is usually difficult to control, with limited substrate scopes. Herein, the formation of stable N-heterocyclic fluoroalkene adducts as versatile synthons for the incorporation of fluoroalkene fragments into various chemical environments will be introduced. By forming these adducts, the inconvenience of manipulating fluorinated gases in further reactions can be avoided, and the N-heterocyclic fragment is shown to aid in directing substitutions involving polyfluoroalkenyl imidazolium salts and organic nucleophiles to form a variety of C-E (E = C, N, O, S) and C-M bonds (M = Mn, Mo). The ease with which C-F bonds are manipulated in these systems is quite remarkable, as the substitution reactions occur cleanly and efficiently at room temperature, to form a variety of new bonds without the need for a transition metal. By expanding on the fundamental reactivity between N-heterocyclic carbenes and fluoroalkenes, attempts were made to correlate the observed reactivity with certain electronic and steric parameters unique to the utilized carbenes. Although a correlation has not yet been established, the effects of atypical steric constraints in a cyclic (alkyl)(amino)carbene were demonstrated, wherein the initial point of attack by the carbene on the fluoroalkene was modified. It is hoped that this work will eventually lead to new roles for organocatalysts in fluoroalkene transformations.

Twenty-seven difluorophosphates are successfully prepared by the displacement reactions of anhydrous chlorides or arylcarboxylates with purified difluorophosphoric acid. Vibrational spectra are obtained for these difluorophosphates and assignments made. The effects of cation-anion interactions on the vibrational frequencies of the PO₂F₂ group are also examined. Mossbauer parameters for five dialkyltin bis-difluorophosphates are reported and compared with those of analogous fluorosulfate derivatives. Electrical conductivity, nuclear magnetic resonance and density studies of solutions of some metal difluorophosphates in difluorophosphoric acid are made in an attempt to obtain a better understanding of solution behaviour in difluorophosphoric acid. / Science, Faculty of / Chemistry, Department of / Graduate