Monomeric and polymeric fluoroalkyl sulfonyl fluorides, sulfonate salts and sulfonic acids have qualities desirable for use as electrolytes in alternative energy sources such as fuel cells and solid polymer electrolyte lithium batteries. Since the nature of the fluoroalkyl group affects the properties of these compounds, new monomeric and polymeric fluoroalkyl sulfonyl fluorides, sulfonate salts and sulfonic acids were prepared in this work. Simple compounds prepared in this work were: the fluoroalkyl sulfonyl fluorides, sulfonate salts and sulfonic acid CHF (OCF₂CF2SO₂ F)₂ CF₂(OCF₂CF₂SO₂F) ₂ CH₂(OCF₂CF₂SO3Na) ₂ CF₂(OCF₂CF₂SO3 ) ₂Ca , CF₂(OCF₂CF₂SO3H) ₂ prepared by means of electrochemical fluorination; FC (CF3 ) ₂OCH₂CH₂OCF₂CF₂SO₂F prepared using the adduct of hexafluoroacetone and silver fluoride; CH₃OCF₂CF₂SO₂F prepared as a substrate for free-radical substitution reactions of fluorinated species; and the pentafluorosulfur lithium sulfonate salts SFsCHFSO₃Li and SFsCF₂SO₃Li. Novel compounds containing both alcohol and fluoroalkyl sulfonyl functional groups were prepared: the chlorohydrin ClCH₂CH (OH) CH₂OCF₂CF₂SO₂F; the benzyl ethers HOCH₂CH (OCH₂C6Hs) CH₂OCF₂CF₂SO₂F and C6HsCH₂OCH₂CH (OH) CH₂OCF₂CF₂SO₂F as a product mixture; and the diol HOCH₂CH (OH) CH₂OCF₂CF₂SO₂F. The diol was found to be a useful synthon for the preparation of two polymeric fluoroalkyl sulfonyl fluorides: the polyester [C (O)CF₂CF₂CF₂ C (O) OCH₂CH (CH₂OCF₂) CF₂SO₂F] O]n by reaction with perfluoroglutaric anhydride and a polyurethane formed with 1,6-diisocyanohexane. Other polymeric compounds prepared were: the sulfonyl fluoride, sulfonate salt and sulfonic acid [OCH₂CH (CH₂OCF₂CF₂SO₂F)]n, [OCH₂CH (CH₂OCF₂CF₂SO₃Na)]n, and [OCH₂CH (CH₂OCF₂CF₂SO₃H)]n prepared by homopolymerization of the epoxide OCH₂CHCH₂OCF₂CF₂SO₂F; a cross-linked copolymer of the same epoxide; and the fluoroalkyl sulfonyl fluoride polyacrylat [-CH₂-CH-(CO₂CH₂CH₂CF₂CF₂OCF₂CF₂SO₂F)]n prepared from the acrylate ester H₂C=CHC (O) OCH₂CH₂CF₂SO₂F. ¹H, ¹⁹F and ¹³C nuclear magnetic resonance spectroscopy, infrared spectroscopy, mass spectrometry, melting point or boiling point, elemental analysis, contact angles, optical clarity, refractive index, and specific conductivity were among the techniques used to characterize the compounds.

Thesis (MScEng (Process Engineering))--University of Stellenbosch, 2009. / The abundance of alkane by-products formed in South Africa presents a feedstock opportunity for the production of a wide range of commercially important products, such as long-chain dioic acids and alcohols. These compounds are formed as intermediates through the biological conversion of alkanes, a route which is particularly attractive when compared with chemical conversion due to its operation under milder process conditions. Furthermore, advances in genetic manipulation, which enable the accumulation of a range of metabolic intermediates, make the biological route remarkably flexible. From the literature review Yarrowia lipolytica was identified as a promising organism for use in studying alkane bioconversion because of its ability to produce large quantities of fatty acids when grown on n-paraffins as a sole carbon source. The bioconversion of alkanes will not only depend on the genetic modification but also on the process conditions to maximise growth and bioconversion. The overall objective of this project was therefore to investigate the potential of Y. lipolytica for alkane bioconversion by defining the conditions that maximise both cell growth and bioconversion. The Y. lipolytica strains supplied (TVN348, TVN493 and WT), however, were not yet modified to the extent that accumulation of metabolic intermediates was possible. Use was therefore made of a model system in which the alkane substrate was substituted with an even chain alkylbenzene. Since Y. lipolytica is unable to metabolise the benzene ring, the alkylbenzene is converted to the metabolic intermediate, phenyl acetic acid (PAA), and the potential for bioconversion assessed through measuring the accumulation of PAA. The specific objectives of the project were therefore 1) to define and quantify the parameters for the establishment of an effective model system in shake flasks with respect to trace elements, buffering, added nitrogen, oxygen supply, glucose concentration, alkylbenzene substrate and inducer requirements 2) to use the defined model system to identify the most promising strain of Y. lipolytica TVN348, TVN493 and WT 3) to use the defined model system and selected strain for evaluation of the influence of time of substrate addition and glucose concentration on cell growth and bioconversion of Y. lipolytica under controlled conditions in an instrumented bioreactor Furthermore, since poor reproducibility in cell growth and bioconversion had been prevalent in previous studies, it was also aimed to identify and statistically quantify the reproducibility between duplicate or triplicate samples in each experiment and between sets of different experiments with respect to PAA formation and cell concentrations. Studies were conducted in shake flask cultures to define and quantify the parameters for the model system. The parameters assessed included trace elements, buffering, nitrogen concentration, oxygen supply, glucose concentration, alkylbenzene substrate type and possible inducer requirements. Trace elements, phosphate buffering and added nitrogen did not significantly affect the cell growth of Y. lipolytica TVN348. The cell concentration of Y. lipolytica TVN348 and TVN493 was increased by 65% and 43% respectively for an increase in oxygen supply by decreasing the working volume from 150ml to 50ml, while the cell concentration of Y. lipolytica WT was increased by 41% when oxygen supply was increased by switching from non-baffled to baffled flasks in 50ml cultures. Bioconversion was also increased for an increase in oxygen supply: 2.4mM to 29.0mM PAA (Y. lipolytica TVN348) and 1.2mM to 21.7mM PAA (Y. lipolytica TVN493) for a decrease in working volume; 10.5mM to 46.6mM PAA (Y. lipolytica WT) when switching from non-baffled to baffled flasks. These results indicated that adequate oxygen supply is crucial to both growth and bioconversion, and that further study should be conducted in 50ml working volumes. Cell concentrations obtained in 1.6% (wt/v) and 3.2% (wt/v) glucose cultures (3.95x108cells/ml and 4.03x108cells/ml respectively) indicated that cell growth was neither enhanced nor inhibited by 3.2% (wt/v) glucose. Of the range of substrates examined (propylbenzene, butylbenzene, sec-butylbenzene, hexylbenzene, ethyltoluene and tert-butyltoluene for Y. lipolytica TVN348 and TVN493; octylbenzene and decylbenzene for Y. lipolytica WT), hexylbenzene was regarded as the best substrate for bioconversion (14.7mM and 14.1mM PAA for TVN348 and TVN493 respectively; 42.6mM PAA for WT). Lastly, the absence of a requirement for an additional inducer such as ethanol or oleic acid was confirmed when PAA was formed from hexylbenzene in the culture containing additional glucose (25.0mM). This suggested that when using hexylbenzene as substrate, bioconversion was induced provided sufficient glucose was available for cell maintenance. Results from duplicate or triplicate flasks in each individual shake flask experiment were reproducible and conclusions were based solely on results which showed 95% confidence intervals. However, reproducibility problems were experienced with results between different sets of experiments carried out under the same conditions. The model system was therefore defined by: 1) no addition of trace elements, additional buffering or added nitrogen, 2) cultures grown in 50ml volumes to supply an adequate amount of oxygen crucial for growth and bioconversion, 3) 3.2% (wt/v) glucose and 4) addition of 1% (v/v) hexylbenzene at 24h with no inducer requirements. Use of the model system in shake flask cultures to identify the most promising of the three strains of Y. lipolytica supplied demonstrated that there was no significant difference in cell growth or bioconversion between these strains. Y. lipolytica WT (which has no genetic modifications) was therefore used for further investigation until an appropriate strain could be substituted when it became available. The growth and bioconversion of Y. lipolytica WT was further investigated under controlled conditions in a bioreactor. The influence of time of substrate addition (11h, 24h, 48h) and glucose concentration (3.2% and 6.4% (wt/v)) on growth and bioconversion was examined. When hexylbenzene was added at 48h, cell growth was increased (8.90x108cells/ml) when compared to two of the triplicate cultures with hexylbenzene addition at 24h (4.74x108cells/ml and 3.92x108cells/ml) and the culture with hexylbenzene addition at 11h (2.82x108cells/ml). The third of the triplicate cultures with hexylbenzene addition at 24h, on the other hand, exhibited the strongest growth (2.23x109cells/ml). The poor reproducibility between the triplicate cultures with hexylbenzene addition as 24h made it difficult to determine whether hexylbenzene addition at 24h or 48h maximised cell growth. Furthermore, the cell growth was not significantly improved when the glucose concentration was increased from 3.2% (wt/v) to 6.4% (wt/v) (7.47x108cells/ml for 6.4% glucose culture), however it was also not inhibited. The highest amount of specific PAA formed by Y. lipolytica WT was found when hexylbenzene was added at 11h (7.4x10-11mmol PAA/cell), however the highest accumulated PAA was produced in the culture that exhibited the strongest growth with hexylbenzene addition at 24h (41.4mM). This suggested that the bioconversion of hexylbenzene was maximised when it was added during the active growth phase. It is therefore recommended to conduct fed-batch experiments in future to maintain the active growth phase. Accumulated PAA was increased in 6.4% (wt/v) glucose culture (15.2mM PAA) when compared with two of the 3.2% (wt/v) glucose cultures (5.4mM and 4.3mM PAA). These results indicated that the increased glucose concentration did not inhibit the bioconversion. Furthermore, PAA was formed when 5% (wt/v) residual glucose was observed in the culture, suggesting that the bioconversion of hexylbenzene was not inhibited at glucose concentrations as high as 5.0% (wt/v). If future work were to be conducted in bioreactor culture where glucose is added in fed-batch operation, glucose concentrations in cultures of up to 5% (wt/v) could be considered for initial studies. During bioconversion by Y. lipolytica, the PAA measured after hexylbenzene exhaustion did not, however, correspond to 100% conversion. Further, poor reproducibility was found in the bioreactor cultures. The disappearance of hexylbenzene without a corresponding accumulation of PAA and poor reproducibility was investigated by determining whether PAA was further degraded or alternatively, whether other metabolic intermediates were being formed and accumulated from the hexylbenzene. However, substitution of the hexylbenzene with PAA as substrate confirmed that PAA could not be metabolised. Further, NMR analyses of both the aqueous and organic phases of the culture did not identify any additional metabolic intermediates. It is recommended that additional analyses be conducted on the aqueous and organic phases to further assess the possible accumulation of intermediates. The development of the model system in shake flask cultures demonstrated the importance of adequate oxygen supply for both cell growth and bioconversion. It was also shown that no inducer was needed because hexylbenzene acted as its own substrate inducer. Furthermore, comparison of Y. lipolytica strains TVN348, TVN493 and WT under the defined conditions of the model system revealed that the genetically modified strains (TVN348, TVN493) did not exhibit enhanced bioconversion. Bioreactor cultures using the model system under controlled conditions further showed that bioconversion was not inhibited at a 5% (wt/v) residual glucose concentration and suggested that bioconversion was maximised when hexylbenzene was added during active growth phase. This informs on future work, suggesting fed-batch operation in order to extend the active growth phase, where glucose concentrations in the bioreactor of up to 5% (wt/v) can be considered.

Oxissulfetos e oxissulfatos de terras raras vêm sendo explorado por vários pesquisadores há algum tempo, e são aplicados como materiais marcadores, LEDs, OLEDs, absorvedores de gases, materiais de persistência em luminescência, ou como marcadores para materiais biológicos, magnéticos entre outros. A proposta deste trabalho foi apresentar um processo diferenciado de obtenção de oxissulfetos e oxissulfatos de terras raras (RE3+) por meio da decomposição térmica de sulfatos e sulfonatos de terras raras [RE = Eu3+, Tb3+, Dy3+, Gd3+ e Sm3+], utilizando o método de precursores para a obtenção dos materiais. Os produtos foram isolados sob atmosferas dinâmicas de ar sintético e de CO, com as temperaturas variando de acordo com os patamares de estabilização dos respectivos compostos. A pureza das fases foi investigada a partir dos difratogramas de raios X (DRX) de cada composto, indicada pelas características cristalinas de cada produto. Os DRX dos precursores Tb(DAS)3·2H2O e Eu(DAS)3·7H2O indicaram que os materiais são amorfos. A pureza, também, foi investigada por espectroscopia de absorção no infravermelho (FTIR), para a identificação dos oxissulfetos e oxissulfatos e, ainda, a partir da interação entre os sulfonatos com os íons Eu3+ e Tb3+. As imagens de microscopia eletrônica de varredura (MEV) mostraram diferenças morfológicas entre os materiais cristalinos de oxissulfeto e/ou oxissulfato e de seus precursores sulfonatos. A partir dessas imagens foi possível perceber algumas características hexagonais e quase esféricas para os Eu2O2S derivados de sulfato e sulfonato, respectivamente, e ainda o grande aumento no tamanho das partículas dos Tb2O2S, derivado de sulfatos e sulfonatos. Também foram observadas diferenças nas formas entre os respectivos oxissulfatos. Os espectros de fotoluminescência dos compostos apresentaram as bandas de emissão das transições intraconfiguracionais oriundas dos íons Eu3+ (5D0→7FJ, J=0-6) e Tb3+ (5D4→7FJ, J=6-0), exibindo as cores vermelha e verde, características dos respectivos íons. Além disso, foram observadas as bandas características dos íons Dy3+ que apareceram no composto Dy2O2S, com a banda mais intensa monitorada a partir da transição 4F9/2→6H13/2 correspondente a cor amarela do íon Dy3+. Também, foi possível observar bandas largas e acentuadas de transferência de carga metal-ligante (LMCT) O2-(2p)→Eu3+ nos compostos Eu2O2S e Eu2O2SO4, tanto derivado de sulfato como de sulfonato. Os resultados mostraram que os oxissulfetos e oxissulfatos apresentam patamares de estabilização térmica sob atmosferas oxidantes e redutoras, que possibilitaram isolar os respectivos produtos. Esses materiais podem ser utilizados como fósforos para diversas aplicações como sondas, lasers entre outros. O Dy2O2S mostrou-se um fósforo estável podendo ser mais explorado em pesquisas futuras em emissões de cor amarela e azul. A troca do ânion sulfato pelo sulfonato proporcionou a obtenção de partículas de maior tamanho, indicando que é possível a aplicação destes fósforos em diferentes áreas tecnológicas. / Rare earth Oxysulfides and oxysulfates have been explored by several researchers for some time, and are applied as labels materials, LEDs, OLEDs, gas absorbers, persistence of luminescence materials, or as markers of biological material, magnetic, among others. The purpose of this study was to present a differentiated process of obtaining oxissulfetos and oxissulfatos rare earth (RE3+) by thermal decomposition of sulfates and sulfonates of rare earths [RE = Eu3+, Tb3+, Dy3+, Gd3+ and Sm3+] using the method precursor to obtain the material. The products were isolated under dynamic atmospheres synthetic air and CO, with temperatures varying according to stabilization levels of the respective compounds.The purity of the phases was investigated from of diffraction of X-rays (XRD) of each compound, indicated by the crystalline characteristics of each product. The XRD of precursors Tb(DAS)3·2H2O and Eu(DAS)3·7H2O indicate that the materials are amorphous. Besides, the purity also was investigated by infrared absorption spectroscopy (FTIR), for identifying and oxissulfetos oxissulfatos and also from the interaction between sulfonates with Eu3+ and Tb3+ ions. The scanning electron microscopy images (SEM) showed morphological differences between crystalline materials oxysulfide and/or oxysulfate and their sulfonate precursors. From these images it was possible to realize almost some hexagonal and quasi-spherical characteristics for Eu2O2S derivatives from sulfate and sulfonate, respectively, and also the large increase in particle size of the Tb2O2S derived from sulfates and sulfonates. Also differences were observed in the shapes between the respective oxysulfates. The photoluminescence spectra of the compounds showed the band emission of intraconfigurational transitions from the Eu3+ (5D0→7FJ, J=0-6) and Tb3+ (5D4→7FJ, J=6-0) ions, displaying the red and green colors, characteristics of the respective ions. In addition, they observed the ions of the characteristic bands Dy3+ that appeared in Dy2O2S compound, with the most intense band monitored from the 4F9/2→6H13/2 transition corresponding to yellow ion Dy3+. Also, it was possible to observe large and sharp bands of metal-ligand charge transfer (LMCT) O2-(2p)→Eu3+ the Eu2O2S and Eu2O2SO4 compounds, both derived sulfate and sulfonate. The results showed that the present oxysulfates and oxysulfides and the levels of thermal stabilization under oxidizing and reducing atmospheres, which made it possible to isolate the respective products. These materials can be used as phosphors for various applications as probes, lasers, among others. The Dy2O2S proved to be stable phosphorus can be further explored in future research in yellow and blue color emissions. The anion exchange of sulfate, sulfonate afforded by obtaining larger particles, indicating that the application of these phosphors in different technological areas is possible.

An experimental investigation of the high pressure synthesis of water soluble, self doping conducting polymers is presented. 2- And 3-aminobenzenesulfonic acid and the respective sodium sulfonates have been polymerised. Optimal polymerisation conditions have been determined with respect to yield, conductivity and molecular weight. Reaction parameters such as oxidant, pressure, catalysts, reaction time and temperature and the use of additives were investigated. The minimum pressure required for polymerisation was 7 kbar. An increase in pressure had a negligible effect on polymer characteristics. The polymers were generated in aqueous, non-acidic media, to ensure they were selfdoping when characterised. Conductivities of between 10-6 Scm-1 and 10-3 Scm-1 were measured. The sulfonate salts reacted faster than the sulfonic acids and for both a longer reaction time resulted in higher yields and conductivities. These polymers were completely water soluble, of high molecular weight and able to be cast as thin films. The arylamines 5- and 8-aminonaphthalene-2-sulfonic acid and their respective sodium sulfonates were polymerised at elevated pressure. The naphthalene sulfonate salts polymerised at atmospheric pressure, but displayed a higher molecular weight when reacted under pressure. Generally the naphthalene monomers reacted similarly to the benzene monomers, although there were some differences. Conductivity and yield decreased with increased reaction times and the use of 0.1M equivalents of ferrous sulfate had an negligible effect on the polymers. The polynaphthalenes were highly water soluble, self doping and had conductivities in the order 10-5 to 10-3 Scm-1. A measurement of the activation volume for the polymerisation of 2-methoxyaniline and sodium 8-aminonaphthalene-2-sulfonate was performed. These were determined to be -44 ± 3 cm3mol-1 and -62 ± 10 cm3mol-1 respectively. These large negative values are consistent with rate limiting monomer oxidation.

The aim of this study was to understand the contribution of Linear Alkylbenzene Sulfonates (LAS) to the decline of Mediterranean coastal forest exposed to marine aerosols. LAS are a group of synthetic anionic surfactants widely used in the composition of household or industrial detergents and agrochemicals. This study was part of a large project (RISICO) aiming the assessment of the environmental impact of the LAS at multiple levels: biodegradation in the coastal waters, sorption – desorption processes in the sediments, toxicity to the aquatic life and toxicity to the coastal forest (by aerosolisation of the sea water). Previous studies pointed out this group of surfactants as the main cause of the coastal forest decline. However, the quantification of this surfactant in the environmental samples (mainly sea water and foliar deposition) was done using non-specific analytical methods as methylene blue active substances (MBAS), leading to overestimation of the environmental concentrations of LAS. The work hypothesis was that at actual environmental concentrations, the LAS does not play a key role in the foliar uptake of the sea salt deposited on the coastal vegetation by the marine aerosols, therefore the LAS may not be the main cause of the coastal forest decline. The research involved both greenhouse experiments and field measurements. The experimental work was conducted on young Mediterranean trees (Laurus nobilis L., Quercus ilex L. and Pinus halepensis P. Mill.) and investigated the synergistic toxic effects of exposure to simulated marine aerosol contaminated with surfactants. An array of endpoints was used including photosynthetic activity, relative water content, foliar deposition and uptake of salt and LAS, and pigments analysis. The results of those experiments revealed that LAS itself did not have phytotoxic effects. Nevertheless, the surfactant was shown to enhance the foliar uptake of the salt in the tested species, especially in Pinus halepensis, confirming the conclusions of previous studies regarding the sensitivity of this species to polluted marine aerosols. The field work was conducted in San Rossore National Park (Italy) and Porquerolles Island (France) and was focused on evaluating the health status of the Mediterranean forest (Quercus ilex L., Pinus halepensis Mill. and Pinus pinaster Aiton.) and also on quantification of LAS in coastal aerosols using highly specific analytical methods, like the mass spectrometry (MS). The frequencies and extent of injuries in the coastal trees were found to be correlated to the salt but not with the LAS content of the leaves. The concentrations of LAS in the Pinus and Quercus leaves were comparable in the two studied sites but the concentrations of salt were extremely high in San Rossore, suggesting that other factors may determine the excessive salt foliar uptake. The parallel MS and MBAS carried out in the same set of aerosol samples revealed that MBAS measurements were not relevant for LAS concentrations in the marine aerosols. Projecting the experimental results to the real LAS and salt exposure of the coastal forest, we concluded that LAS may play a marginal role in coastal vegetation decline.

Thesis (Ph.D.); Submitted to Department of Chemical Engineering, Colorado School of Mines, Golden, CO (US); 1 Sep 2004. / Published through the Information Bridge: DOE Scientific and Technical Information. "LA-14178-T" R.L. Ames. 09/01/2004. Report is also available in paper and microfiche from NTIS.

Oxissulfetos e oxissulfatos de terras raras vêm sendo explorado por vários pesquisadores há algum tempo, e são aplicados como materiais marcadores, LEDs, OLEDs, absorvedores de gases, materiais de persistência em luminescência, ou como marcadores para materiais biológicos, magnéticos entre outros. A proposta deste trabalho foi apresentar um processo diferenciado de obtenção de oxissulfetos e oxissulfatos de terras raras (RE3+) por meio da decomposição térmica de sulfatos e sulfonatos de terras raras [RE = Eu3+, Tb3+, Dy3+, Gd3+ e Sm3+], utilizando o método de precursores para a obtenção dos materiais. Os produtos foram isolados sob atmosferas dinâmicas de ar sintético e de CO, com as temperaturas variando de acordo com os patamares de estabilização dos respectivos compostos. A pureza das fases foi investigada a partir dos difratogramas de raios X (DRX) de cada composto, indicada pelas características cristalinas de cada produto. Os DRX dos precursores Tb(DAS)3·2H2O e Eu(DAS)3·7H2O indicaram que os materiais são amorfos. A pureza, também, foi investigada por espectroscopia de absorção no infravermelho (FTIR), para a identificação dos oxissulfetos e oxissulfatos e, ainda, a partir da interação entre os sulfonatos com os íons Eu3+ e Tb3+. As imagens de microscopia eletrônica de varredura (MEV) mostraram diferenças morfológicas entre os materiais cristalinos de oxissulfeto e/ou oxissulfato e de seus precursores sulfonatos. A partir dessas imagens foi possível perceber algumas características hexagonais e quase esféricas para os Eu2O2S derivados de sulfato e sulfonato, respectivamente, e ainda o grande aumento no tamanho das partículas dos Tb2O2S, derivado de sulfatos e sulfonatos. Também foram observadas diferenças nas formas entre os respectivos oxissulfatos. Os espectros de fotoluminescência dos compostos apresentaram as bandas de emissão das transições intraconfiguracionais oriundas dos íons Eu3+ (5D0→7FJ, J=0-6) e Tb3+ (5D4→7FJ, J=6-0), exibindo as cores vermelha e verde, características dos respectivos íons. Além disso, foram observadas as bandas características dos íons Dy3+ que apareceram no composto Dy2O2S, com a banda mais intensa monitorada a partir da transição 4F9/2→6H13/2 correspondente a cor amarela do íon Dy3+. Também, foi possível observar bandas largas e acentuadas de transferência de carga metal-ligante (LMCT) O2-(2p)→Eu3+ nos compostos Eu2O2S e Eu2O2SO4, tanto derivado de sulfato como de sulfonato. Os resultados mostraram que os oxissulfetos e oxissulfatos apresentam patamares de estabilização térmica sob atmosferas oxidantes e redutoras, que possibilitaram isolar os respectivos produtos. Esses materiais podem ser utilizados como fósforos para diversas aplicações como sondas, lasers entre outros. O Dy2O2S mostrou-se um fósforo estável podendo ser mais explorado em pesquisas futuras em emissões de cor amarela e azul. A troca do ânion sulfato pelo sulfonato proporcionou a obtenção de partículas de maior tamanho, indicando que é possível a aplicação destes fósforos em diferentes áreas tecnológicas. / Rare earth Oxysulfides and oxysulfates have been explored by several researchers for some time, and are applied as labels materials, LEDs, OLEDs, gas absorbers, persistence of luminescence materials, or as markers of biological material, magnetic, among others. The purpose of this study was to present a differentiated process of obtaining oxissulfetos and oxissulfatos rare earth (RE3+) by thermal decomposition of sulfates and sulfonates of rare earths [RE = Eu3+, Tb3+, Dy3+, Gd3+ and Sm3+] using the method precursor to obtain the material. The products were isolated under dynamic atmospheres synthetic air and CO, with temperatures varying according to stabilization levels of the respective compounds.The purity of the phases was investigated from of diffraction of X-rays (XRD) of each compound, indicated by the crystalline characteristics of each product. The XRD of precursors Tb(DAS)3·2H2O and Eu(DAS)3·7H2O indicate that the materials are amorphous. Besides, the purity also was investigated by infrared absorption spectroscopy (FTIR), for identifying and oxissulfetos oxissulfatos and also from the interaction between sulfonates with Eu3+ and Tb3+ ions. The scanning electron microscopy images (SEM) showed morphological differences between crystalline materials oxysulfide and/or oxysulfate and their sulfonate precursors. From these images it was possible to realize almost some hexagonal and quasi-spherical characteristics for Eu2O2S derivatives from sulfate and sulfonate, respectively, and also the large increase in particle size of the Tb2O2S derived from sulfates and sulfonates. Also differences were observed in the shapes between the respective oxysulfates. The photoluminescence spectra of the compounds showed the band emission of intraconfigurational transitions from the Eu3+ (5D0→7FJ, J=0-6) and Tb3+ (5D4→7FJ, J=6-0) ions, displaying the red and green colors, characteristics of the respective ions. In addition, they observed the ions of the characteristic bands Dy3+ that appeared in Dy2O2S compound, with the most intense band monitored from the 4F9/2→6H13/2 transition corresponding to yellow ion Dy3+. Also, it was possible to observe large and sharp bands of metal-ligand charge transfer (LMCT) O2-(2p)→Eu3+ the Eu2O2S and Eu2O2SO4 compounds, both derived sulfate and sulfonate. The results showed that the present oxysulfates and oxysulfides and the levels of thermal stabilization under oxidizing and reducing atmospheres, which made it possible to isolate the respective products. These materials can be used as phosphors for various applications as probes, lasers, among others. The Dy2O2S proved to be stable phosphorus can be further explored in future research in yellow and blue color emissions. The anion exchange of sulfate, sulfonate afforded by obtaining larger particles, indicating that the application of these phosphors in different technological areas is possible.

The aim of this study was to understand the contribution of Linear Alkylbenzene Sulfonates (LAS) to the decline of Mediterranean coastal forest exposed to marine aerosols. LAS are a group of synthetic anionic surfactants widely used in the composition of household or industrial detergents and agrochemicals. This study was part of a large project (RISICO) aiming the assessment of the environmental impact of the LAS at multiple levels: biodegradation in the coastal waters, sorption – desorption processes in the sediments, toxicity to the aquatic life and toxicity to the coastal forest (by aerosolisation of the sea water). <p>Previous studies pointed out this group of surfactants as the main cause of the coastal forest decline. However, the quantification of this surfactant in the environmental samples (mainly sea water and foliar deposition) was done using non-specific analytical methods as methylene blue active substances (MBAS), leading to overestimation of the environmental concentrations of LAS. <p>The work hypothesis was that at actual environmental concentrations, the LAS does not play a key role in the foliar uptake of the sea salt deposited on the coastal vegetation by the marine aerosols, therefore the LAS may not be the main cause of the coastal forest decline. <p>The research involved both greenhouse experiments and field measurements. The experimental work was conducted on young Mediterranean trees (Laurus nobilis L. Quercus ilex L. and Pinus halepensis P. Mill.) and investigated the synergistic toxic effects of exposure to simulated marine aerosol contaminated with surfactants. An array of endpoints was used including photosynthetic activity, relative water content, foliar deposition and uptake of salt and LAS, and pigments analysis. The results of those experiments revealed that LAS itself did not have phytotoxic effects. Nevertheless, the surfactant was shown to enhance the foliar uptake of the salt in the tested species, especially in Pinus halepensis, confirming the conclusions of previous studies regarding the sensitivity of this species to polluted marine aerosols. <p>The field work was conducted in San Rossore National Park (Italy) and Porquerolles Island (France) and was focused on evaluating the health status of the Mediterranean forest (Quercus ilex L. Pinus halepensis Mill. and Pinus pinaster Aiton.) and also on quantification of LAS in coastal aerosols using highly specific analytical methods, like the mass spectrometry (MS). The frequencies and extent of injuries in the coastal trees were found to be correlated to the salt but not with the LAS content of the leaves. The concentrations of LAS in the Pinus and Quercus leaves were comparable in the two studied sites but the concentrations of salt were extremely high in San Rossore, suggesting that other factors may determine the excessive salt foliar uptake. The parallel MS and MBAS carried out in the same set of aerosol samples revealed that MBAS measurements were not relevant for LAS concentrations in the marine aerosols. Projecting the experimental results to the real LAS and salt exposure of the coastal forest, we concluded that LAS may play a marginal role in coastal vegetation decline. <p> / Doctorat en Sciences / info:eu-repo/semantics/nonPublished

No description available.

(1) Introduction: Sulfonates, which can be diet- or host-derived, are a class of compounds detected in the gut, are involved in host–microbiome interactions and have several health effects. Our aim was to develop a method to quantify five of the sulfonates in the intestine and apply it in a simplified human microbiome model. These were taurine, its metabolic precursor cysteate and one of its degradation products isethionate, as well as sulfoquinovose and one of its most relevant degradation products 2,3-dihydroxy-1-propanesulfonate. (2) Methods: An extraction and sample preparation method was developed, without the need for derivatization. To detect and quantify the extracted sulfonates, a multiplexed LC-MS/MS-MRM method was established. (3) Results: The accuracy and precision of the method were within GLP-accepted parameters. To apply this method in a pilot study, we spiked either taurine or sulfoquinovose into an in vitro simplified human microbiota model with and without Bilophila wadsworthia, a known sulfonate utilizer. The results revealed that only the culture with B. wadsworthia was able to degrade taurine, with isethionate as an intermediate. After spiking the communities with sulfoquinovose, the results revealed that the simplified human microbiome model was able to degrade sulfoquinovose to 2,3-dihydroxypropane-1-sulfonate, which was probably catalyzed by Escherichia coli. In the community with B. wadsworthia, the 2,3-dihydroxypropane-1-sulfonate produced was further degraded by B. wadsworthia to sulfide. (4) Conclusions: We successfully developed a method for sulfonate quantification and applied it in a first pilot study.