Fluorinated compounds are produced on a large scale and their releases are contaminating the environment. Among these are side-chain fluorinated polymers found in technical mixtures of Scotchgard™, which are used as surfactants in fabric coating. Today, the knowledge about these Scotchgard products (Pre-2002 and Post-2002, formulations used in Scotchgard products before and after 2002) and side-chain fluorinated polymers, in general, are limited, and more studies need to be performed to increase the understanding of the behaviour of the compounds and their fate in the environment. This study performed sorption tests in liquid to sediment ratio of 100:1, with sediment from Lake Hjälmaren, Sweden, and water spiked with Pre-2002 and Post-2002. The waters were Milli-Q water, containing CaCl2, adjusted to different pHs (range between 4.4 and 11.2) with NaOH, and on water from Lake Hjälmaren. The solutions were shaken for 0.5, 1, 2, 4, 8, 12, 24 and 168 h. Liquid-liquid extraction with tert-butyl methyl ether (MTBE) was used to extract the remaining target compounds in the aqueous phase and analysed using ultra-performance liquid chromatography (UPLC). For the different pH solutions, the result showed both Pre-2002 and Post-2002 readily sorbed to the sediment with close to 0 % remaining in the aqueous phase after 4 hours. For the first time point, 0.5 h, more than 7 % remained in the aqueous phase with a pH of 11.2, while under 1 % remained with a pH of 4.4 for both Pre-2002 and Post-2002, showing that the sorption capacity was dependent on pH. In water from Lake Hjälmaren, neither of the target analytes were under the limit of detection (LOD) until the time point of 168 h. In contrast to the result of the pH solutions, Post-2002 were shown to be more prone to sorb to the sediment in the water from Lake Hjälmaren than Pre-2002. This might be due to particles, ions and competing per- and polyfluoroalkyl substances (PFAS) present in the water. However, the pH of Lake Hjälmaren was around 5; when comparing the data, the amount sorbed, somewhat aligned with what would be expected based on the sorption test with different pHs, indicating that the sorption capacity might be more dependent on pH than water chemistry.

No description available.

No description available.

No description available.

Detta projekt syftar till att undersöka den termiska rusningsprocessen hos ett litiumjonbatteri med en fluorfri elektrolyt och jämföra den med en kommersiellt använd fluor-innehållande elektrolyt. Battericellerna innehöll silikon-grafit som anod och LiNi0.6Mn0.2Co0.2O2 (NMC622) som katod. Den fluorfria elektrolyten var baserad på litium bis(oxalato)borat (LiBOB) i organisk lösning med additivet vinylen karbonat(VC). Det jämfördes med en fluor-innehållande elektrolyt med LiPF6 i samma organiska lösning tillsammans med VC och fluoroetylene karbonat (FEC). De termiska stabilitetstesterna utfördes med Accelerating Rate Calorimetry (ARC) och Differentiell svepkalorimetri (DSC). Både knappceller och pouchceller har undersökts med hjälp av ARC. Trots flera försök med olika uppställning kunde den termiska rusningen inte bli detekterad för någon av celltyperna, med slutsatsen att en störremängd aktivt material behövs. Istället användes DSC för att undersöka de termiska reaktionerna hos batteri-komponenterna. Resultaten visade att anoden var mer termisk stabil med den fluorfria elektolyten, medan samma elektrolyt visade mindre termisk stabilitet på katoden. Vidare undersökningar behövs dock för bekräftelse av katoden. / This project aims to investigate the thermal runaway process of fluorine-free lithium ion battery cells and to compare this with a commercially used fluorinated electrolyte. The cells consisted of a silicon-graphite composite anode and a LiNi0.6Mn0.2Co0.2O2(NMC622) cathode. The non-fluorinated electrolyte used was based on lithiumbis(oxalato)borate (LiBOB) in organic solvents with the additive vinylene carbonate(VC). Moreover, the fluorinated electrolyte consisted of LiPF6 in the same organic solvents together with VC and fluoroethylene carbonate (FEC). The thermal stability measurements have included Accelerating Rate Calorimetry (ARC) and Differential Scanning Calorimetry (DSC). Moreover, both coin cells and pouch cells have been examined by ARC. However, thermal runaway could not be detected for either type of cells, concluding that a greater amount of active material was needed. In order to measure the thermal reactions of the battery components, DSC was used. These results concluded that the anode was more thermally stable with a non-fluorinated electrolyte. However, the thermal stability appeared to be lower for the cathode, therefore, further investigation is needed for confirmation of the cathode.

A series of reactive phenylethynyl endcapped imide oligomers has been prepared in either fully cyclized or amic acid precursor form. Soluble oligomers have been synthesized with controlled molecular weights ranging from 2- to 12 Kg/mol. Molecular weight characterization was performed using SEC (size exclusion chromatography) and 13C-NMR, revealing good agreement between the theoretical and experimental (Mn) values. Crosslinked polyimides were obtained by solution or melt processing the oligomers into films and gradually heating in a programmed temperature manner up to the appropriate reaction temperature for the phenylethynyl groups, which is approximately 350-400°C. Thermal analysis of the resulting films showed high glass transition temperatures (>300°C) and excellent thermal stability, comparable to those found for thermoplastic control polyimides. The crosslinked films also had exceptional solvent resistance as evidenced by a high gel fraction (greater than or equal to 95%) following extraction in common solvents for several days. This was in contrast to the amorphous thermoplastic controls, which quickly dissolved upon immersion in solvents. The monomers used for synthesizing the polyimide oligomers were varied systematically within the series to study the influence of both molecular structure and molecular weight on the physical and film-forming properties. The incorporation of fluorinated monomers, such as 4,4'-(hexafluoroisopropylidene)diphthalic anhydride (6FDA), reduced water absorption and lowered the dielectric constant relative to non-fluorinated polyimides in the series. When flexible ether linkages were incorporated in the repeat unit by using 4,4'-oxydianiline (ODA), relatively more ductile solvent-cast films were obtained from oligomers having Mn values as low as 10 Kg/mol. Additionally, oligomer Mn and the relative rigidity/symmetry of the repeat unit structure greatly influenced the solubility of polyimides in NMP. For example, even 6FDA/p-phenylenediamine based oligomers with Mn values targeted below 10 Kg/mol precipitated from NMP at 180°C during solution imidization. The relationship between solution viscosities of polyimide and poly(amic acid) thermosetting oligomers and wetting/spreading ability to form continuous films during spin casting was elucidated. Employing o-dimethoxybenzene (DMB) as a cosolvent with NMP improved the film-forming ability of the fully imidized 6FDA/ODA oligomer series. This was evidenced by a decrease in viscosity (via suppression of physical-type gel formation) and better overall coverage and clarity of the films. Humidity was found to have a detrimental effect, causing the polyimide oligomers to phase separate to form cloudy or porous films. When moisture was reduced, oligomers having Mn greater than or equal to 6 Kg/mol formed spin cast films of <20 micrometer thickness with good qualitative adhesion to several inorganic substrates. Dielectric constants (epsilon) were estimated for several of the polyimides by measuring the refractive indices (n) of the films and using Maxwell's relationship (epsilon at optical frequencies is equal to n raised to the second power). The apparent dielectric constants were low, ranging from 2.47 to 2.75. The novel combination of low dielectric constant, solvent resistance and isotropic physical properties inherent in the thermosetting polyimide oligomers makes these materials excellent candidates for use as thin film insulating layers in microelectronics packaging applications. / Ph. D.

Le tripeptide GPE possède une activité neuroprotectrice intéressante in-vitro et in-vivo pour différents types de dommage neuronaux. L'objectif de cette thèse est de mettre au point des méthodes de couplage peptidique pour les acides aminés trifluorométhylés et de réaliser des analogues trifluorométhylés du GPE.Au cours de cette thèse, la synthèse d'acides aminés trifluorométhylés cycliques énantiopurs (proline, pseudoproline) a été réalisée à l'échelle du gramme.Ensuite, une étude méthodologique de l'incorporation de ces acides aminés trifluorométhylés dans des peptides a été effectuée.Des expériences RMN ont été menées pour étudier la conformation cis/trans de la liaison amide de ces peptides trifluorométhylés.Enfin, des analogues du tripeptides GPE ont été synthétisé en remplaçant le motif proline par une proline ou pseudoproline trifluorométhylé. Des tests biologiques sont actuellement en cours pour évaluer leur activité sur divers troubles neuronaux. / GPE is a tripeptide with neuroprotecting activity both in-vitro and in-vivo for various neuronal dammage. The goal of this thesis was to work out peptide coupling methods for trifluoromethylated amino acids and the synthesis of trifluoromethylated analogs of GPE.During this thesis, the synthesis of enantiopure cyclic trifluoromethylated amino acids (proline and pseudoprolines) was performed successfully on grams scale.Then, methodological study of their incorporation in peptide was performed.NMR experiments were made to investigate the cis/trans conformation of the amide bound of trifluoromethylated peptide. At last, analogs of the tripeptide GPE were made with trifluoromethylated proline and pseudoprolines instead of the proline. Biological tests are currently under progress to evaluate their activity on various neuronal disorders.

Cette thèse concerne l’auto-assemblage d'alcanes semi-fluorés (FnHm) et de fluorocarbures (FCs) aux interfaces et leurs interactions avec des phospholipides (PLs) en 2D et 3D. Nous avons étudié les sphérulites formées dans des films de diblocs FnHm. La morphologie de ces sphérulites, concentrique ou radiale, est contrôlée par la longueur des blocs Fn et Hm et la vitesse de refroidissement. Les nanodomaines de diblocs FnHm dans les monocouches de Langmuir sont incompressibles et forment des gels physiques 2D, même à pression nulle. Les blocs Hm sont cristallisés et inclinés d’ ~30°C par rapport à la normale à la surface. La réflectivité de neutrons a montré que l’albumine adsorbée sur des monocouches de PL est désorbée par un FC gazeux. Ce résultat pourrait permettre de lutter contre l’inactivation du surfactant pulmonaire par les protéines sériques. L’ajout de diblocs à des films de PLs accroit l'élasticité des monocouches. Nous avons préparé des microbulles stables à parois de PLs/FnHm, les diblocs agissant en co-surfactants. / This thesis focuses on the self-assembly of semi-fluorinated alkanes (FnHm) and fluorocarbons (FCs) at interfaces and their interactions with phospholipids (PLs) in 2D and 3D. 2D Spherulites were identified in FnHm films for the first time. Their morphology, ring-banded or radial, was controlled by varying block lengths and cooling rate. Nanodomains of FnHm in monolayers formed incompressible 2D physical gels, even at zero surface pressure. The Hm segments are crystalline and titled by 30°C to the normal to the surface. Neutron reflectivity showed that albumin adsorbed on PLs monolayers is desorbed by exposure to FC gas, which opens the potential use of FCs to treat the inactivation of the lung surfactant by serum proteins. Incorporating FnHm into PL monolayers increases their elasticity. Small, stable microbubbles of PLs/FnHm were obtained. FnHm diblocks function as co-surfactants for stabilizing microbubbles.

Foi realizado um estudo, a fim de comparar o efeito na redução do ataque de cárie de uma solução de fluoreto de sódio, na concentração de 0,5 por cento , aplicada sob a forma de bochecho, escovação e escovaçao e bochecho, uma vez por semana, sob supervisão, durante um período escolar de 10 meses, em 424 escolares de 9 e 10 anos de idade matriculados em cinco escolas estaduais da cidade de são Paulo. As crianças foram distribuídas igualmente em três grupos experimentais e um grupo controle, de acordo com a idade dental (número de superfícies de dentes permanentes irrompidas) e experiência anterior de cárie (CPOS). Ao final do estudo, 307 crianças foram examinadas e os resultados mostram que houve uma redução, estatisticamente significante ao nível de 0,05 do ataque de cárie, entre os grupos experimentais e controle da ordem de 30,50 por cento para o grupo de bochecho (grupo I), de 32,68 por cento para o grupo de escovação (grupo II) e de 46,77 por cento para o grupo de escovação e bochecho (grupo IV), para as superfícies presentes no início do estudo. Para as superfícies que irromperam durante o estudo as reduções foram da ordem de 69,19 por cento (grupo I), de 76,23 por cento (grupo II) e de 71,83 por cento (grupo IV). Em relação as superfícies presentes no início e nas que irromperam durante o estudo as diferenças foram da ordem de 35,19 por cento (grupo I), de 37,91 por cento (grupo II) e de 49,77 por cento (grupo IV). Quando comparados os grupos experimentais entre si nao houve diferenças estatisticamente significantes ao nível de 0,05 presentes ou/e no final do estudo. / A study has been accomplished to make a comparison of the anti cariogenic effect of a solution of sodium fluoride, in the concentration of 0,5 per cent , applied weekly and under supervision, as mouthwash and toothbrushing used independently or in combination, during 10 school months, on 424 children of 9 and 10 years of age from five public schools of São Paulo, Brazil. The children were equally distributed in three experimental groups and one control group according to the dental age (number of erupted permanent teeth surfaces) and caries experience (DMFS). At the end of the study 307 children were examined and the results show a statistically significant decrease at the 0,05 level in the caries experience between the experimental and control groups: 30,50 per cent for the mouthwash, (group I); 32,68 per cent toothbrushing,( group II) ;and 46,77 per cent mouthwash and toothbrushing, (group IV) on the surfaces presented at the beginning of the study; of 69,19 per cent (group I), 76,23. per cent (group II) and 71,83 per cent (group IV) on the surfaces that erupted during the study, and of 35,19 per cent (group I), 37,91 per cent (group II) and 49,77 per cent (group IV) on the surfaces present at the beginning and the surfaces that erupted during the study. When the experimental groups were compared there was no significant difference of proportions at the 0,05 level.

Foi realizado um estudo, a fim de comparar o efeito na redução do ataque de cárie de uma solução de fluoreto de sódio, na concentração de 0,5 por cento , aplicada sob a forma de bochecho, escovação e escovaçao e bochecho, uma vez por semana, sob supervisão, durante um período escolar de 10 meses, em 424 escolares de 9 e 10 anos de idade matriculados em cinco escolas estaduais da cidade de são Paulo. As crianças foram distribuídas igualmente em três grupos experimentais e um grupo controle, de acordo com a idade dental (número de superfícies de dentes permanentes irrompidas) e experiência anterior de cárie (CPOS). Ao final do estudo, 307 crianças foram examinadas e os resultados mostram que houve uma redução, estatisticamente significante ao nível de 0,05 do ataque de cárie, entre os grupos experimentais e controle da ordem de 30,50 por cento para o grupo de bochecho (grupo I), de 32,68 por cento para o grupo de escovação (grupo II) e de 46,77 por cento para o grupo de escovação e bochecho (grupo IV), para as superfícies presentes no início do estudo. Para as superfícies que irromperam durante o estudo as reduções foram da ordem de 69,19 por cento (grupo I), de 76,23 por cento (grupo II) e de 71,83 por cento (grupo IV). Em relação as superfícies presentes no início e nas que irromperam durante o estudo as diferenças foram da ordem de 35,19 por cento (grupo I), de 37,91 por cento (grupo II) e de 49,77 por cento (grupo IV). Quando comparados os grupos experimentais entre si nao houve diferenças estatisticamente significantes ao nível de 0,05 presentes ou/e no final do estudo. / A study has been accomplished to make a comparison of the anti cariogenic effect of a solution of sodium fluoride, in the concentration of 0,5 per cent , applied weekly and under supervision, as mouthwash and toothbrushing used independently or in combination, during 10 school months, on 424 children of 9 and 10 years of age from five public schools of São Paulo, Brazil. The children were equally distributed in three experimental groups and one control group according to the dental age (number of erupted permanent teeth surfaces) and caries experience (DMFS). At the end of the study 307 children were examined and the results show a statistically significant decrease at the 0,05 level in the caries experience between the experimental and control groups: 30,50 per cent for the mouthwash, (group I); 32,68 per cent toothbrushing,( group II) ;and 46,77 per cent mouthwash and toothbrushing, (group IV) on the surfaces presented at the beginning of the study; of 69,19 per cent (group I), 76,23. per cent (group II) and 71,83 per cent (group IV) on the surfaces that erupted during the study, and of 35,19 per cent (group I), 37,91 per cent (group II) and 49,77 per cent (group IV) on the surfaces present at the beginning and the surfaces that erupted during the study. When the experimental groups were compared there was no significant difference of proportions at the 0,05 level.