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The mode of antibacterial action of 2-thiocyanatobenzamide and some of its derivativesFuller, S. J. January 1986 (has links)
No description available.
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Preparation and testing of lanthanum and neodymium with 8-hydroxyquinoline as potential biocideTarverdi, Karnik January 1989 (has links)
No description available.
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Performance of a Catch Basin Filter and Leachate from Biocidal Media for Stormwater TreatmentMaclure, Ryan Scott 01 March 2009 (has links) (PDF)
The feasibility of installing biocidal beads into a catch basin filter insert for simultaneous stormwater disinfection and contaminant removal was tested. The catch basin filter insert (DrainPac®) was tested for its sediment, oil and grease, and coliform bacteria removal efficiency in conjunction with bench-scale testing of biocidal polymer beads. DrainPac® catch basin filters are composed of a metal frame, polypropylene filter fabric, and a high-density polymer support basket, and are installed below storm drains. A 12 x 41 in. DrainPac® filter (United Stormwater, Inc.) insert was set in a flume that simulated a large-scale catchment basin. Pond water was gravity fed to the flume at flow rates up to 200 gpm. The pond water contained fine sediments at concentrations ranging from 30-50 mg/L. The biocidal beads were tested in a small laboratory column for potential application to stormwater treatment. The head loss through the clean filter insert varied from 0.5 cm at 20 gpm to 9.1 cm at 200 gpm. Head loss of 21.5 cm occurred after 625 g of solids were added to the filter at 200 gpm at which point water began bypassing the filter fabric and flowing through the mesh screen. The highest flow rate that could be filtered through the loaded filter was 80 gpm. The DrainPac® filter removed total suspended solids with efficiencies ranging from 83% to 91% at flow rates of 20 to 200 gpm, with higher removal efficiencies at lower flow rates. The oil and grease removal efficiency of the DrainPac® filter ranged from 40% to 82%. The DrainPac® filter exhibited no removal of coliform bacteria under these test conditions. Biocidal brominated polystyrene beads, developed by Dr. S. D. Worley at Auburn University, were tested in a 1-cm diameter laboratory column apparatus for leaching of bromine compounds, which is important for determining if the filters will meet water quality regulations of the receiving waters. Removal efficiencies of coliform bacteria were tested in a companion study by Cal Poly graduate student Alex Bowerman. Pond water was passed through a 1-cm thick bed of beads in an up-flow direction. Leachate was analyzed for bromine, bromide, and bromoform. Leaching from both 0.3-mm and 0.8-mm biocidal beads was tested in the column apparatus. Samples collected for bromoform analysis were quenched with sodium thiosulfate, and the time before samples were quenched had a drastic effect on bromoform concentrations. Samples quenched after the collection of the total sample were assumed to be the most realistic for stormwater conditions since stormwater entering catch basins isn’t immediately discharged into its receiving waters. Effluent from a 1-cm bed of 0.3-mm beads at 0.56 mL/sec contained the following average concentrations: 0.47 mg/L bromine, 2.45 mg/L bromoform, and 0.53 mg/L bromide. The same conditions for 0.8 mm beads resulted in effluent containing the following average concentrations: 0.27 mg/L bromine, 0.06 mg/L bromoform, and 0.50 mg/L bromide. The much lower concentrations of bromine measured in the 0.8-mm bead leachate was likely due to the greater surface area of the smaller beads. The greater leaching of bromoform from the 0.3 mm beads may be partly attributed to the greater surface area of the smaller beads, but also the manufacturer of the beads reported that different production methods were used for the 0.3 mm beads. Higher bromine compound concentrations were found at lower flow rates, due to the longer contact times with the beads. Deionized (DI) water that was used to initially wet the biocidal beads before passing pond water through the column was also analyzed for bromoform. The DI flush water from the 0.3 mm beads contained 1.25 mg/L bromoform at a flow rate of 0.28 mL/sec. Bromoform concentrations in the DI flush water from the 0.8 mm beads at the same flow rate were below detection. Bromoform is expected to be formed as bromine is reduced to bromide by the presence of organics. Since there are no organics present in DI water to form such high concentrations of bromoform as those found from the 0.3-mm bead DI flush water, it appears that bromoform could have leached from the surface of the 0.3 mm beads. The longevity of the bromine treatment of the biocidal beads was tested on one set of 0.3-mm beads by simulating five use cycles, and also by testing another set of beads after dry storage. Each use cycle was simulated by pumping pond water through a 1-cm bed of 0.3 mm beads at 0.56 mL/sec for one hour and then connecting the column to an air pump to dry for 23 hours. After five simulated uses, leachate from the beads showed only a slight reduction in concentrations of bromine and bromide (21% and 4% less than fresh beads, respectively), while the concentration of bromoform was nearly 100 times less. The drastic decrease in bromoform concentration suggests that after five simulated uses, much of the bromoform was exhausted or conditions for the formation of bromoform were no longer present. For the dry storage test, 0.3 mm beads were wetted with 1-L DI water and then stored dry for 162 days. Then pond water was pumped through the column at 0.56 mL/sec and the leachate was analyzed. After dry storage for 162 days, the leachate showed no reduction in bromine concentrations compared to fresh beads, a 97% reduction in bromoform, and a 30% increase in bromide concentrations. This significant reduction in bromoform could be due to the volatilization of bromoform off the surface of the 0.3 mm beads during dry storage. The 0.3 mm beads are no longer being manufactured, and leachate from the 0.8 mm beads contained bromoform at concentrations below the potable drinking water maximum contaminant level of 80 µg/L. Under all tested conditions, bromine, bromide, and bromoform are present in the leachate from the biocidal beads, and thus their applicability for stormwater disinfection depends on the longevity of the bromine compounds in receiving waters, and on the regulations governing these compounds.
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Synthesis, characterization, biocidal and virucidal properties of metal oxide nanoparticlesHaggstrom, Johanna A. January 1900 (has links)
Doctor of Philosophy / Department of Chemistry / Kenneth J. Klabunde / Non-polar halogens (Cl2, Br2 and I2) and polar interhalogen molecules (ICl, IBr and ICl3) have been adsorbed on the surface of several high surface area materials, including three different nanosized metal oxides (NanoActive® (NA) Al2O3 Plus, NA-TiO2 and NA-CeO2). The prepared halogen and interhalogen adducts have been characterized in detail by thermogravimetric analysis (TGA), UV-Vis, Raman and X-ray photoelectron spectroscopies (XPS) and the results are discussed herein. The different metal oxides lead to varying strength of adsorption of the halogen/interhalogen in the prepared adducts and adsorption is stronger in the nanosized metal oxides as compared to their macrocrystalline available counterparts.
Nanosized metal oxide halogen adducts possess high surface reactivities due to their unique surface morphologies. These adducts have been used as reactive materials against vegetative cells, such as Escherichia coli and Bacillus megaterium, as well as spores, including Bacillus subtilis and Bacillus anthracis (Δ Sterne strain). High biocidal activities against both Gram-positive and Gram-negative bacteria, as well as spores have been obtained. Bactericidal test procedures include a water suspension method and a dry membrane method and the results illustrate that good results are obtained using both procedures. Transmission electron micrographs have been used to illustrate the treated and untreated cells and spores, giving insight into the mechanism. It is proposed that the abrasive character of the particles, along with the oxidative power of the halogens/interhalogens as well as the electrostatic attraction between some of the metal oxides and the biological material are main reasons for the high biocidal activities.
Three different bacteriophages (MS2, φX174 and PRD1) have also been studied and initial results indicate that there is big potential for the use of metal oxide halogen and interhalogen adducts for the destruction of viruses. Other potential uses for them also include halogenating agents in organic and inorganic synthesis as well as a safe way to store intact halogens.
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Nanocomposites interactifs supportes en tant que photocatalyseurs contemporains et materiaux germicides : concepts et applications / Supported Interactive Nanocomposites as Contemporary Photocatalysts and Germicidal Materials : concept and ApplicationGärban, Razvan Vasile 12 July 2011 (has links)
La recherche actuelle est entreprise dans l’optique de la révision complète du design chimique et des principes d’élaboration des photocatalyseurs composites supportés (PCCS) afin d’améliorer considérablement leurs capacités réactionnelles, la durabilité de leur action en temps et de résoudre le problème de pollution secondaire des milieux à traiter. Les travaux effectués ont permis la mise en œuvre d’un nouveau modèle de PCCS interactifs dont les composants photosensibles sont en fortes interactions chimiques avec leurs supports appartenant au groupe d’acides de Lewis. Cette particularité assure une grande sélectivité d’action des produits développés, leur fonctionnement durable en régime stationnaire, évite la pollution secondaire des effluents à traiter et garanti une performance photocatalytique comparable à celle du produit de référence Degussa P25.Les travaux réalisés ont permis d’acquérir de nouvelles connaissances scientifiques concernant le rôle de l’acidité de surface dans l’action photocatalytique et du taux de dissociation de l’eau adsorbée sur le produit actif. De plus, un ensemble de huit paramètres principaux assurant les meilleures conditions d’exploitation des PCCS a été établi.Les PCCS développés peuvent être appliqués, tout d’abord, dans le domaine de l’incinération photocatalytique des COV. Un prototype de filtre dynamique capable de traiter 50 m3/h de l’air avec une consommation d’énergie modérée, est conçu. Un nouveau type de matériaux composites à vocation germicide à base de polymères synthétiques fait également l’objet de la partie applicative de ces travaux de thèse. / The current research is undertaken in the context of the complete reconsideration of the supported composite photocatalysts (SCPC) chemical design and elaboration principles in order to improve their reaction capacities, to assure the sustainability of their action in time and to resolve the secondary pollution problem for the media to treat. This work enabled the implementation of a new model of interactive SCPC in which the photosensitive components occur in a strong chemical interaction with their supports belonging to the Lewis acid group. This feature provides the developed products with high selectivity, allows them to function in the stationary conditions, avoids the secondary pollution effect and guarantees the photocatalytic performance comparable with the one of the reference industrial photocatalyst Degussa P25. An important scientific knowledge on the role of the surface acidity in the photocatalytic action and on the dissociation state of the water adsorbed over the active product was acquired. Apart from this, a set of eight main parameters ensuring the best SCPC operation properties was established. The developed SCPC are forecasted to be firstly applied in the photocatalytic VOC oxidation processes. A prototype of such filter capable to treat 50 m3/h of air, having modest energy consumption, was designed. A new composite material with germicidal properties elaborated using synthetic polymer supports, also constitutes a subject of the applications part of this thesis.
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Obtenção de resinas sulfofosforiladas com propriedades biocidas / Obtaining sulphophosphorylated resins with biocidal propertiesMarcelo Augusto Vieira de Souza 27 April 2012 (has links)
Neste trabalho, foram preparadas resinas contendo o grupo sulfofosforila a partir de copolímeros de estireno e divinilbenzeno (Sty-DVB). O copolímero sintetizado Sty-DVB foi modificado com PCl3 e AlCl3 durante 15 horas de reação em diferentes condições de temperatura e razão molar P/Al. Os copolímeros fosforilados obtidos nas diferentes condições tiveram o teor de fósforo dosado por espectrofotometria para avaliar a extensão da modificação, sendo também caracterizados por espectroscopia na região do infravermelho (FTIR), termogravimetria, microscopia óptica (MO) e microscopia eletrônica de varredura (MEV). A resina fosforilada otimizada de maior percentual de fósforo incorporado foi obtida empregando-se o tempo de reação de 15 horas, temperatura de 50 C e razão molar P/Al = 1/1,5. Essas condições otimizadas de fosforilação foram empregadas para obtenção da resina fosforilada RMF em larga escala. A resina fosforilada foi modificada com CS2 à temperatura ambiente em diferentes condições de tempo e quantidade molar adicionada do agente de sulforação (CS2). A resina sulfofosforilada otimizada de maior percentual de enxofre incorporado, determinado por análise elementar, foi obtida empregando-se o tempo de reação de 6 dias e adição de 15 mL de CS2, à temperatura ambiente. As resinas sulfofosforiladas foram também caracterizadas por FTIR, termogravimetria, MO e MEV, e tiveram a capacidade biocida avaliada através da determinação do número de células viáveis utilizando a técnica de contagem em placa junto à suspensão de Escherichia coli (ATCC25922TM, tipo selvagem). A maior capacidade biocida foi observada na resina sulfofosforilada com maior teor de enxofre incorporado / In this work, resins containing the sulfophosphoryl group were prepared from synthesized styrene and divinylbenzene (Sty-DVB) copolymers. The synthesized Sty-DVB copolymer was modified with PCl3 and AlCl3 for 15 hours under different conditions of temperature and P/Al molar ratio. The phosphorylated copolymers obtained under different conditions were assayed by spectrophotometry to measure the content of incorporated phosphorus and the extent of modification, and also characterized by infra-red spectrometry (FTIR), thermogravimetry, optical microscopy (MO) and scanning electron microscopy (SEM). The phosphorylated resin with the highest content of phosphorus was obtained by using the time of 15 hours, temperature of 50 C and P/Al molar ratio = 1/1.5. These optimized conditions were employed to obtain phosphorylated resin RMF in large scale. The phosphorylated resin was modified at room temperature with CS2 under different conditions of time and the molar amount added of the sulforation agent (CS2). The sulfophosphorylated resin with the highest content of sulfur, determined by elemental analysis, was obtained by using the reaction time of 6 days and addition of 15 mL CS2, at room temperature. The sulfophosphorylated resins were characterized by FTIR, thermogravimetric analysis, MO e MEV, and had the biocidal activity evaluated by determining the number of viable cells of Escherichia coli (ATCC25922TM, wild type) using the technique of plate counting. The sulfophosphorylated resin with the highest biocidal activity was the resin obtained with highest content of incorporated sulfur
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Obtenção de resinas sulfofosforiladas com propriedades biocidas / Obtaining sulphophosphorylated resins with biocidal propertiesMarcelo Augusto Vieira de Souza 27 April 2012 (has links)
Neste trabalho, foram preparadas resinas contendo o grupo sulfofosforila a partir de copolímeros de estireno e divinilbenzeno (Sty-DVB). O copolímero sintetizado Sty-DVB foi modificado com PCl3 e AlCl3 durante 15 horas de reação em diferentes condições de temperatura e razão molar P/Al. Os copolímeros fosforilados obtidos nas diferentes condições tiveram o teor de fósforo dosado por espectrofotometria para avaliar a extensão da modificação, sendo também caracterizados por espectroscopia na região do infravermelho (FTIR), termogravimetria, microscopia óptica (MO) e microscopia eletrônica de varredura (MEV). A resina fosforilada otimizada de maior percentual de fósforo incorporado foi obtida empregando-se o tempo de reação de 15 horas, temperatura de 50 C e razão molar P/Al = 1/1,5. Essas condições otimizadas de fosforilação foram empregadas para obtenção da resina fosforilada RMF em larga escala. A resina fosforilada foi modificada com CS2 à temperatura ambiente em diferentes condições de tempo e quantidade molar adicionada do agente de sulforação (CS2). A resina sulfofosforilada otimizada de maior percentual de enxofre incorporado, determinado por análise elementar, foi obtida empregando-se o tempo de reação de 6 dias e adição de 15 mL de CS2, à temperatura ambiente. As resinas sulfofosforiladas foram também caracterizadas por FTIR, termogravimetria, MO e MEV, e tiveram a capacidade biocida avaliada através da determinação do número de células viáveis utilizando a técnica de contagem em placa junto à suspensão de Escherichia coli (ATCC25922TM, tipo selvagem). A maior capacidade biocida foi observada na resina sulfofosforilada com maior teor de enxofre incorporado / In this work, resins containing the sulfophosphoryl group were prepared from synthesized styrene and divinylbenzene (Sty-DVB) copolymers. The synthesized Sty-DVB copolymer was modified with PCl3 and AlCl3 for 15 hours under different conditions of temperature and P/Al molar ratio. The phosphorylated copolymers obtained under different conditions were assayed by spectrophotometry to measure the content of incorporated phosphorus and the extent of modification, and also characterized by infra-red spectrometry (FTIR), thermogravimetry, optical microscopy (MO) and scanning electron microscopy (SEM). The phosphorylated resin with the highest content of phosphorus was obtained by using the time of 15 hours, temperature of 50 C and P/Al molar ratio = 1/1.5. These optimized conditions were employed to obtain phosphorylated resin RMF in large scale. The phosphorylated resin was modified at room temperature with CS2 under different conditions of time and the molar amount added of the sulforation agent (CS2). The sulfophosphorylated resin with the highest content of sulfur, determined by elemental analysis, was obtained by using the reaction time of 6 days and addition of 15 mL CS2, at room temperature. The sulfophosphorylated resins were characterized by FTIR, thermogravimetric analysis, MO e MEV, and had the biocidal activity evaluated by determining the number of viable cells of Escherichia coli (ATCC25922TM, wild type) using the technique of plate counting. The sulfophosphorylated resin with the highest biocidal activity was the resin obtained with highest content of incorporated sulfur
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Ecoconception de nouveaux agents biocides à base de nanoparticules d'argent à enrobage bio-inspiré / Ecoconception of new biocidal agent made of silver nanoparticles with biomimetic coatingMarchioni, Marianne 15 October 2018 (has links)
Les nanoparticules d'argent sont de plus en plus utilisées dans les objets de consommation courante ainsi que dans les dispositifs médicaux pour leur activité biocide, qui est due au relargage d'ions Ag(I) au cours du temps. Le recul sur ces nano-objets et en particulier sur leur innocuité n'est toujours pas suffisant et les études sur leur transformation et leur impact in vivo sont sujets à d’intenses recherches. En effet, le devenir dans l’organisme des macro- et micro-matériaux étudiés classiquement n’est pas le même que celles des nanomatériaux. Les nanoparticules d’argent illustrent bien cette problématique : l’argent soluble injecté par voie intraveineuse est éliminé plus rapidement que la même quantité d’argent injectée sous forme nanoparticulaire. De plus, la concentration en argent retrouvée dans le sang et les organes est dix fois supérieure lorsque les nanoparticules d’argent sont injectées plutôt qu’ingérées. C'est pourquoi le développement de produits implantatoires qui se retrouvent donc en contact direct avec l’organisme, et qui contiennent des nanoparticules d’argent doit prendre en compte les risques associés, ce qui peut se faire par une approche Safer-by-design.Une des composantes principales du développement Safer-by-design concerne la fonctionnalisation des nano-objets. L’affinité des thiolates pour l’ion Ag(I) étant très forte, des ligands thiolés pourraient donc constituer une piste pour la fonctionnalisation des nanoparticules d’argent. Néanmoins, il est connu que les molécules thiolées conduisent à différents comportements allant de la dissolution de la nanoparticule d’argent en ions Ag(I) à la simple passivation de la surface de la nanoparticule ce qui peut entrainer la perte de son activité biocide.Ainsi, l’Ecoconception de Nouveaux Agents Biocides à base de Nanoparticules d’Argent à Enrobage Bio-inspiré avait pour objectif principal de poser les bases conceptuelles du développement d’un agent biocide Safer-by-design constitué de nanoparticules d’argent et de molécules thiolées en se positionnant à l’interface de plusieurs disciplines.Le développement de ce projet a nécessité d’étudier la réactivité de diverses molécules biologiques ou bio-inspirées thiolées avec les nanoparticules d’argent. Ainsi, nous avons mis en évidence l’importance de la pré-organisation architecturale des biomolécules dans la cinétique de dissolution, ainsi que le nombre de thiols libres dans la molécule. Dans le cas de composés induisant la dissolution des nanoparticules, sa cinétique augmente avec le nombre de thiols libres présents sur la molécule, et avec la pré-organisation du site de liaison du métal. Le projet principal de cette thèse a ensuite mené à la preuve de concept recherchée, avec le développement d’un nouvel agent biocide composé de nanoparticules d’argents pontées entre elles par un ligand thiolé tripode symétrique qui est le mime chimique d’un site de liaison d’une métallothionéine. Ces assemblages de nanoparticules se sont montrés actifs contre les bactéries (E. coli) et moins toxiques sur les cellules eucaryotes (HepG2), malgré une entrée dans les cellules similaire. Enfin, un criblage a également été réalisé avec des polyéthylèneglycols possédant un à huit thiols et des longueurs de polymères variables dans le but d’essayer de rationaliser les différences de comportement des nanoparticules d’argent en présence des molécules thiolées. Ce travail, a conduit à l’observation des comportements très variés qui vont permettre d’explorer de nouvelles voies de développements de biocides à base d’assemblages de nanoparticules médiés par des liaisons thiol – Ag(I).L’ensemble de ce travail de thèse a donc permis à la fois un travail très fondamental sur la réactivité des thiols vis-à-vis des atomes d’argent à la surface des nanoparticules et au développement de produits à potentiel applicatif, les assemblages de nanoparticules d’argent qui sont des biocides Safer-by-design. / Silver nanoparticles are increasingly used in everyday consumer goods as well as in medical devices for their biocidal activity, which is due to the release of Ag(I) ions over time. The hindsight on these nano-objects and, in particular, on their safety is still not sufficient and studies on their transformation and their impact in vivo is currently an intense research field. Indeed, the fate in the body of macro- and micro-materials studied classically is not the same as for nanomaterials. The case of the silver nanoparticles illustrates this problem: the soluble silver injected intravenously is eliminated faster than the same amount of silver injected in nanoparticular form. Moreover, the concentration of silver found in the bloodstream and organs is ten times higher when silver nanoparticles are injected rather than ingested. The development of silver nanoparticle-containing implanted devices, that get in direct contact with the body, must thus take into account the related risks. A Safer-by-design approach could be a way to solve this issue.One of the main components of Safer-by-design development is the functionalization of nano-objects. The affinity of the thiolates for Ag(I) ions is very high, which would make thiolated ligands a good tool for silver nanoparticle functionalization. However, it is known that the thiolated molecules lead to different behaviors, ranging from the dissolution of silver nanoparticles into Ag(I) ions to the simple passivation of the surface of the nanoparticles, which leads to the loss of their biocidal activity.The Ecodesign of New Biocidal Agents based on Silver Nanoparticles and Bio-inspired Coating is therefore at the interface of several research areas and its main objective was to lay the conceptual foundations for the development of a Safer-by-design biocidal agent based on the interaction between silver nanoparticles and thiolated molecules.The development of this project required to study the reactivity of various biological or bio-inspired thiolated molecules with silver nanoparticles. First of all, we have highlighted the importance of the architectural pre-organization of biomolecules in the dissolution kinetics, as well as the role of the number of free thiols in the molecule. In the case of molecules inducing the dissolution of the nanoparticles, its kinetics increases with the number of free thiols present on the molecule and with the pre-organization of the metal binding site. In a second time, the main project of this thesis was the development of a proof of concept of a new biocidal agent composed of silver nanoparticles bridged together via a thiolated ligand, which is the chemical mimic of one binding site of a metallothionein. These nanoparticle assemblies were active against bacteria (E. coli) and less toxic than silver nanoparticles on eukaryote cells (HepG2), despite a similar cellular entry. Finally, a screening was performed with polyethylene glycols having two to eight thiols and varying polymer lengths in an attempt to rationalize the differences in the behavior of silver nanoparticles in the presence of the thiolated molecules. This ongoing work leads to various behaviors that will enable to explore novel ways for the development of biocidal based on nanoparticles assemblies mediated by thiol – Ag(I) bonds.Therefore, this overall PhD work allows performing both very fundamental researches concerning the reactivity of thiols with surface silver atoms of the nanoparticles and the development of products with application potential, silver nanoparticle assemblies that are Safer-by-design biocide.
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Development of a silver ion-based water purifierRagusa, Paul J. January 1900 (has links)
Master of Science / Department of Biology / Peter P. Wong / Abstract
Water purification methods that remove pathogens and harmful or distasting molecules make water potable. Recently, silver loaded ion-exchange resins have demonstrated a strong role in removing microbes. The goal is to make an effective silver ion-based water purifier that is portable, environmentally stable, and cost efficient.
The project was conducted as a collaborative effort with Safewater A/S, an up and coming entrepreneurial business located in Denmark that is interested in developing novel water purifiers for developing nations, adventurers and military personnel. Purolite, a prominent business in ion-exchange resins located in Whales, designed and provided Safewater A/S and our research team with experimental resins for water purification, which will be discussed in the body of this thesis.
The data reveals critical issues that may render this tool unavailable for commercial production in some countries due to the mode of action for killing the bacteria and the amount of silver leaching. Tests were conducted using Escherichia coli K12 and Enterococcus faecalis OG1SSp as model fecal organisms using different silver ion-exchange resins. Surveillance of leached silver ions, pH changes, and total dissolved solids (TDS) were also monitored to find correlations with capacity (liters of purified water produced) and effectiveness of microbicidal action.
Overall, one resin was found to contain properties consistent with the stated objectives; however its use in some countries as a water purifier for human consumption will be nullified due to extensive silver leaching. Although this resin could be used in the United States of America since it passes the Environmental Protection Agency (EPA) standards, Safewater A/S is interested in further developing it for countries with stricter regulatory constraints before mass production. The goal of the present thesis report is to address the stated objectives in the development of a water purifier.
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Greffage de copolymères antibactériens sur des surfaces PVC par chimie Click / Antibacterial copolymers grafting onto PVC surfaces by click chemistryLafarge, Jérôme 20 December 2012 (has links)
Dans le cadre de ce travail, l’objectif était d’élaborer des surfaces PVC antibactériennes. Deux types de surfaces ont été élaborés, des surfaces bactéricides visant à tuer les bactéries au contact et des surfaces antiadhésives (bactériophobes) empêchant ou limitant l’adhésion bactérienne.Pour ce faire, des copolymères porteurs de groupements cationiques bactéricides ainsi que des copolymères renfermant des structures à effets antiadhésifs de type polysaccharides ou PEG ont été synthétisés et caractérisés. Ces composés ont été ensuite greffés chimiquement par click addition sur des surfaces PVC porteuses de fonctions azoture (PVC-N3). Les propriétés physico-chimiques des nouvelles surfaces obtenues ont été caractérisées par diverses techniques (IRTF, XPS, angle de contact, AFM, microscopie confocale à fluorescence, ATG etDSC). Les propriétés bactéricides ou antiadhésives ont été évaluées à l’égard de Escherichia coli et Staphylococcus epidermidis. La microscopie confocale à fluorescence a mis en évidence le caractère hautement bactéricide des surfaces PVC cationiques via le test Live and Dead.Cette technique a aussi permis de démontrer l’effet antiadhésif de la méthyl cellulose, del’hydroxyéthyl cellulose et du PEG greffés en surface, diminuant d’au moins 10⁴ fois le nombre de bactéries adhérées par rapport aux surfaces témoins. / This work aimed to elaborate antibacterial PVC surfaces. Two kinds of surface were prepared, i.e. non leaching bactericidal surfaces killing bacteria by contact and antiadhesive (bacteriarepellent) surfaces preventing or limiting bacteria attachment. Thus, copolymers bearing cationic bactericidal groups as well as copolymers bearing polysaccharide or PEG antiadhesive structures were synthesized and characterized. These polymers were then successfully grafted by click chemistry onto PVC surfaces bearing azide groups (PVC-N3).The physico-chemical properties of the obtained surfaces were assessed by several techniques(FTIR, XPS, contact angle measurements, AFM, confocal fluorescence microscopy, TGA and DSC). The bactericidal and antiadhesive properties were assessed against Escherichia coli and Staphylococcus epidermidis. The fluorescence microscopy evidenced the high bactericidal effect of the cationic surfaces, using the Live and Dead test. This microscopytechnique has also shown high bacteria repellent effect of the surfaces based on methyl cellulose, hydroxyethyl cellulose and PEG, i.e. decrease of bacteria attachment by more than 10⁴ fold compared to the ungrafted surface.
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