La base phosphazène ButP4 associée au thiophénol ou au bis (2-mercaptoéthyl) éther a été utilisée avec succès pour amorcer quantitativement la polymérisation anionique par ouverture de cycle des monomères cyclopropane-1,1-dicarboxylates de dialkyle. Pour des températures comprises entre 30 et 60°C dans le THF ou entre 30 et 100°C dans le toluéne, le mécanisme observé est celui d'une polymérisation anionique vivante qui conduit à des polymères présentant des indices de polymolécularité faibles et dont les Mn expérimentaux (mesurés par SEC et RMN 1H) sont en accord avec les valeurs théoriques. D'autres systèmes déamorçage comme le carbazole ou des composés possédant un proton acide associés à ButP4 conduisent également à des polymères bien définis. Une étude cinétique montre que l'ordre interne en monomère est égal à 1 sur l'ensemble de la gamme de conversion. Le système déamorçage thiophénol / ButP4 dans le THF présente une réactivité bien supérieure à celle du thiophénolate de sodium dans le DMSO qui est le système classique d'amorçage pour ce type de polymérisation. Différents agents de terminaison, comme l'acide chlorhydrique, le bromure d'allyle ou le bromure de propargyle, ont été utilisés pour terminer les réactions et ont conduit à l'obtention de polyméres hétérotéléchéliques. D'autres dérivés de cyclopropanes présentant des substituants variés ont également été examinés. Ces résultats ouvrent de très intéressantes perspectives dans la préparation d'architectures complexes comme des copolyméres à blocs, greffés ou en étoile. Les premières expériences de copolymérisation ont d'ailleurs été couronnées de succès. Afin d'obtenir de nouveaux canaux ioniques artificiels, différents monomères cyclopropane-1,1- dicarboxylates porteurs d'éthers-couronne ont été synthétisés. La polymérisation anionique par ouverture de cycle de ceux-ci a été étudiée en utilisant soit le thiophénolate de sodium soit le système thiophénol / ButP4 comme amorceur. Ces travaux ont également permis l'obtention d'un nouveau type de poly(éther-ester) qui s'est révélé intéressant comme perméabilisant membranaire. Les interactions des oligo(éther-ester)s avec des membranes modèles planes, des vésicules unilamellaires et des cellules ont été étudiées en collaboration avec des physiciens et des biologistes. Des résultats prometteurs en termes de transport d'ions ont été obtenus et sont présentés dans ce mémoire / The tetrameric phosphazene base ButP4 in association with thiophenol or bis(2-mercaptoethyl) ether has been successfully used in order to initiate the anionic ring-opening polymerization of di-n-alkyl cyclopropane-1,1-dicarboxylates. Well-defined monofunctional or difunctional polymers with a very narrow molecular weight distribution were obtained through a living process at temperatures between 30 and 60°C in THF or between 30 and 100°C in toluene. An excellent agreement is observed between theoretical and experimental Mn values (measured by SEC and by NMR). Other initiating systems such as carbazole or compounds with an acidic proton in association with ButP4 lead also to welldefined polymers. A kinetic study shows a first order with respect to the monomer concentration over the entire conversion range. The initiating system thiophenol / ButP4 in THF shows a much higher reactivity compared to the alkali metal thiophenolate which is the classical one. The living ends were reacted with different terminating agents such as hydrochloric acid, allyl and propargyl bromide thus leading to telechelic polymers. Other cyclopropane derivatives with various substituents have been also examined. These results open very exciting perspectives for the preparation of new architectures such as block and graft copolymers, star polymers. The first copolymer attempts were very successful. With the aim of designing new ion channel biomimics, cyclopropane-1,1-dicarboxylate monomers with crown-ethers substituents were synthesized. The anionic ring-opening polymerization of these monomers has been investigated using either sodium thiophenolate or thiophenol activated by ButP4. Moreover a new alternating poly(ether-ester) was obtained which is an interesting membrane permeabilizer. Its interaction with unilamellar vesicles, planar phospholipidic membranes and cells was studied in collaboration with biophysicists and biologists. Very promising results have been obtained

O presente trabalho trata da preparação e da caracterização de sistemas contendo tetrassulfoftalocianinas de Co(II) (CoPcTs) e Fe(III) (FePcTs) intercaladas ou somente adsorvidas externamente em matrizes de hidróxidos duplos lamelares (HDLs). Foram sintetizados materiais com composições variadas e empregando-se diferentes métodos de síntese visando, principalmente, o isolamento de materiais com microporosidade intracristalina e/ou com um baixo grau de agregação da ftalocianina. Técnicas de caracterização textural (difração de raios-X e medidas de área superficial) e espectroscópicas (vibracional na região do infravermelho, eletrônica no UV/visível, ressonância paramagnética eletrônica e absorção de raios-X), além das análises elementar (C, H, N e metais) e termogravimétrica foram utilizadas para a caracterização dos sólidos sintetizados. Avaliaram-se os materiais como catalisadores na reação de oxidação do 2,6-di-terc-butilfenol e do catecol, utilizando O2ou H2O2 como oxidantes. Nos materiais isolados contendo a CoPcTs intercalada em HDLs com composição MgxAl (x = 2, 3 e 4) e ZnxAl (x = 4 e 5), a ftalocianina está orientada perpendicularmente às lamelas do HDL, independentemente do método de síntese e da composição dos HDLs utilizados. Adicionalmente, constatou-se que a CoPcTs intercalada está altamente agregada e que os materiais não possuem microporosidade. Porém, a diminuição da densidade de carga do HDL provoca uma pequena diminuição na agregação da CoPcTs. Sob determinada condição sintética, a CoPcTs intercalada nos HDLs ZnxAl sofre o processo de enxertia através dos grupos sulfônicos. Quando testados como catalisadores na oxidação do 2,6-di-terc-butilfenol, os materiais contendo a CoPcTs intercalada e enxertada apresentaram reatividade inexpressiva, que pode ser devida ao acesso restrito do substrato ao sítio ativo na região interlamelar. Estudos de adsorção da FePcTs em HDLs MgxAl na forma carbonato, investigados por espectroscopia eletrônica UV/Visível in situ, mostraram uma elevada tendência de agregação da ftalocianina na superfície dos HDLs. Os espectros eletrônicos indicaram também que diferentes espécies derivadas da FePcTs são formadas durante o processo de adsorção nos HDLs e que a densidade de carga influencia o tipo de espécie adsorvida: há predominância de um dímero do tipo µ-oxo nos HDLs Mg2Al e Mg3Al e do dímero (FePcTs)2 no HDL Mg4Al. Os espectros de absorção de raios-X (XANES) da FePcTs adsorvida nos HDLs MgxAl mostraram que as espécies adsorvidas apresentam geometria piramidal de base quadrada (C4v) e/ou octaédrica (Oh), corroborando com os dados de espectroscopia no UV/Visível. Já os espectros de ressonância paramagnética eletrônica mostraram que a ftalocianina de Fe(III) quando adsorvida nos HDLs gera uma mistura de espécies com configuração de baixo spin e alto spin e, também, elevada distorção rômbica. A FePcTs adsorvida nos HDLs MgxAl apresentou estabilidade e reatividade catalítica superior quando comparada com a ftalocianina livre na oxidação dos fenóis. A ftalocianina adsorvida na superfície externa do HDL deve favorecer o acesso do substrato ao sítio ativo. Uma correlação entre os estudos de adsorção e os resultados dos testes catalíticos mostrou que a espécie dimérica do tipo µ-oxo pode ser a espécie mais ativa na oxidação dos fenóis. Nestes sistemas, as camadas positivas do HDL devem provocar um enfraquecimento da ligação O-H do fenol, facilitando a sua desprotonação (uma das etapas do mecanismo de oxidação). Este último efeito pareceu atuante, pois foram observadas reatividades crescentes dos catalisadores à medida que se aumentava a densidade de carga do HDL. Estes resultados indicaram que existe um efeito cooperativo nos HDLs MgxAl contendo a FePcTs adsorvida, mostrando que o HDL não atua como um suporte inerte nos processos estudados. / The present work describes the preparation and characterization of materials containing Co(II) and Fe(III) tetrasulfonated phthalocyanines (CoPcTs and FePcTs, respectively) intercalated or adsorbed on layered double hydroxides (LDHs). Different compositions and synthetic methods were used to isolate materials with microporosity and/or the phthalocyanine in a low aggregation degree. X-ray diffraction analysis, surface area measurements, spectroscopic techniques (infrared, UV/visible and X-ray absorption), elemental analysis and thermogravimetry were used to characterize the solids. The materials were tested as catalysts in the 2,6-di-terc-butilfenol and catechol oxidation, using O2 or H2O2 as oxidants. In the materials prepared by intercalation of the CoPcTs in MgxAl (x = 2, 3 and 4) and ZnxAl (x = 4 and 5) LDHs, the phthalocyanine is perpendicularly orientated related to the LDH layers, regardless of synthetic method or LDH composition used. In addition, it was observed that the intercalated phthalocyanine is aggregated and the solids do not have microporous. However, the aggregation degree of the phthalocyanine is slightly lower when the LDH charge density decreases. Under a particular synthetic conditions the CoPcTs intercalated in the LDH ZnxAl is grafted through the sulfonic groups. Catalytic tests uisng this material in the 2,6-di-terc-butilfenol oxidation showed a neglectful reactivity, which confirms the aggregation of the intercalated CoPcTs, thus avoiding that the substrate accesses the reactive center. In an adsorption study carried by monitoring in situ the FePcTs UV/Vis electronic spectra during its addition to LDH suspensions, a strong tendency of aggregation was observed for the FePcTs. In addition, different FePcTs species are formed during the adsorption process on the LDHs, which is influenced by the LDH charge density: the µ-oxo complex is the main species adsorbed on the Mg2Al and Mg3Al LDHs, whereas for Mg4Al the non oxo-bridged dimeric complex prevailed. X-ray absorption spectra (XANES) of the adsorbed FePcTs on the MgxAl LDHs showed that the species present a square-pyramidal (C4v) and/or an octahedral (Oh) symmetry, in agreement with the UV/visible spectroscopic data. EPR spectra of these samples showed that the FePcTs adsorbed on the LDHs leads to a mixture of Fe(III) high and low spin species along with a strong rhombic distortion. The FePcTs adsorbed on the MgxAl LDHs showed an enhanced catalytic activity and longevity in the phenols oxidation compared to the homogeneous counterpart. The phthalocyanine on the LDH external surfaces allows the access of the substrate to the reactive metal center. A correlation between the adsorption study and the catalytic tests pointed that the FePcTs µ-oxo complex may be the active species in the oxidation of phenols. Furthermore, the positive charge of LDH layers may weaken the O-H bonding in the phenol molecules making them more easily ionized (one step of the phenol oxidation mechanism). This feature seems to be effective because higher activities of the catalysts were observed along with increasing charge density of the LDHs. These results indicated that a cooperative effect takes place in the materials containing the FePcTs adsorbed on the MgxAl LDHs, showing that LDH do not act as an inert support in the studied catalytic reactions.

A invertase comercial (Bioinvert®) foi imobilizada por adsorção em resinas aniônicas do tipo Dowex® [1x8:50-400, 1x4:50-400 e 1x2:100-400, todos copolímeros estireno-divinilbenzênicos, porém de granulometria (50-400 mesh) e quantidades de ligações cruzadas diferentes (2-8%)] em meio aquoso. A melhor percentagem de adsorção da invertase nas resinas foi observada em pH 5,5 a 32°C, tendo o complexo Dowex®1x4-200/lnvertase apresentado índice de adsorção e coeficiente de imobilização iguais a 100%. Os parâmetros cinéticos e termodinâmicos foram determinados para a invertase solúvel e insolúvel de Bioinvert® e também para a invertase purificada (Fluka®). O complexo Dowex®1 x4-200/Bioinvert® apresentou-se estável durante as reações sem desprendimento da enzima do suporte. Os parâmetros termodinâmicos da forma solúvel e insolúvel da Fluka® foram idênticos aos do Bioinvert®, no entanto, após a imobilização apresentou uma redução de 28% na sua atividade. O estudo da atividade transferásica de ambas as formas de Bioinvert® em diferentes concentrações de sacarose foram analisadas através da cromatografia de camada delgada. A estabilidade operacional e de estocagem foi também determinada para o complexo Dowex®1x4-200/Bioinvert®. / The invertase (trademarked as Bioinvert®) solubilized in deionized water was immobilized by adsorption on anion exchange resins, collectively named Dowex®, [1x8:50-400, 1x4:50-400 and 1x2:100-400, styrene-divinylbenzene copolymers, with different granulometry (50-400mesh) and different degrees of cross-linking (2-8%)]. The best percentage of adsorption of invertase on resins was observed in pH 5.5 at 32°C and the complex Dowex®1x4-200/invertase has shown a coupling yield and an immobilization coefficient equal to 100%. The thermodynamic and kinetic parameters for sucrosehydrolysis for both soluble and insoluble enzyme were evaluated to Bioinvert® and purified invertase purchased from Fluka®. The complex Dowex®/Bioinvert® was stable without any desorption of enzyme from the support during the reaction and having the thermodynamic parameters equal to the soluble formo However, the loss of activity for immobilized Fluka® was found to be 28% when compared to the soluble one. The transfructosylating activity of Bioinvert® in both forms in different concentrations of sucrose was investigated through TLC. In regard to insoluble Bioinvert® its storage and operational stability were also determined.

O projeto consistiu em avaliar o emprego de polímeros catiônicos e aniônicos de diferentes pesos moleculares como auxiliares de filtração no tratamento de águas de abastecimento proveniente de mananciais com alto grau de eutrofização com vistas a possibilitar a otimização da remoção de material particulado e minimização da evolução da perda de carga. O aparato experimental é composto, principalmente, por 4 filtros em escala piloto de alta taxa do tipo camada profunda e fluxo descendente por gravidade operados em paralelo. Os filtros possuem 5 m de altura e diâmetro interno de 150 mm. O procedimento experimental foi dividido em três etapas, execução de ensaios de fluidificação e expansão do leito dos filtros e utilização de polímeros catiônicos e de polímero aniônico como auxiliares de filtração. A primeira etapa teve como objetivo definir parâmetros de dimensionamento do sistema de lavagem em contra-corrente com ar e água e nas duas etapas seguintes foram realizados os ensaios de filtração a uma taxa de 500 m³/m²/dia, com a utilização dos polímeros com três dosagens diferentes. Os polímeros utilizados foram CA-2577, CA-2581, CD-2592 e N1986. Estes possuem estrutura e pesos moleculares variáveis, de forma que o trabalho tivesse uma maior amplitude. Os valores médios de turbidez, para a primeira etapa dos ensaios de filtração, foram de 2,36 ± 0,28 UNT e 1,12 ± 0,21 UNT para água bruta e decantada, respectivamente, 0,26 ± 0,07 UNT para o filtro F1 com antracito, 0,25 ± 0,08 UNT para o filtro F3 com antracito e adição de polímero, 0,29 ± 0,08 UNT para o filtro F2 com areia e 0,26 ± 0,08 UNT para o filtro F4 com areia e adição de polímero. Para a segunda etapa dos ensaios de filtração os valores médios de turbidez foram de 2,03 ± 0,36 UNT para água bruta, 0,80 ± 0,21 UNT para água decantada, 0,09 ± 0,03 UNT para o filtro F1, sem adição de polímero, e 0,15 ± 0,04, 0,16 ± 0,03 e 0,10 ± 0,04 UNT para os filtros F2, F3 e F4, respectivamente, todos com adição de polímero. Os resultados experimentais possibilitaram concluir que a adoção do antracito como material filtrante do tipo camada única e profunda apresenta a vantagem de permitir uma menor velocidade ascensional de água de lavagem para uma determinada expansão quando comparado a um filtro de areia de idêntica granulometria. A aplicação dos polímeros catiônicos e do polímero aniônico como auxiliares de filtração não proporcionou para nenhuma dosagem utilizada melhora significativa no comportamento dos filtros. Uma eventual melhora ou piora foi insignificante e estava ligada à qualidade da água decantada. No que diz respeito à perda de carga, os filtros com antracito tiveram carreiras de filtração mais longas quando comparados com os de areia, independente da utilização dos polímeros. / The project was to evaluate the use of anionic and cationic polymers of different molecular weights as filter aids to treat drinking water treatment of surface water sources with high degree of eutrophication, particularly with regard to particulate matter removal optimization and head loss rate minimization. The experimental apparatus was composed of four pilot scale, deep bed, down flow rapid gravity filters, operated in parallel. The filter columns were 5 m high, had inner diameter of 150 mm. The experimental procedure was divided in three stages, conduction of media fluidization and media expansion tests and cationic and anionic polymers application as filter aid. The first stage aims was to define design parameters for the filter backwashing system with water and air and in the two next phases the tests were conducted at a filtration rate of 500 m³/m²/day, with the use of polymers with three different dosages. The polymers tested were CA- 2577, CA-2581, CD-2592 and N1986. They have different structure and molecular weights, thus making wider the array of possibilities tested. The average values of turbidity, for the first stage of testing filtration, were 2.36 ± 0.28 and 1.12 ± 0.21 NTU for raw and settled water, respectively, 0.26 ± 0.07 NTU to the filter F1 with anthracite, 0.25 ± 0.08 NTU for the filter F3 with anthracite and addition of polymer, 0.29 ± 0.08 NTU for the filter F2 with sand and 0.26 ± 0.08 NTU for the filter F4 with sand and the addition of polymer. For the second stage of testing of the filter values of turbidity were 2.03 ± 0.36 NTU for raw water, 0.80 ± 0.21 NTU for settled water, 0.09 ± 0.03 for the filter F1, without the addition of polymer, and 0.15 ± 0.04, 0.16 ± 0.03 and 0.10 ± 0.04 NTU for filters F2, F3 and F4, respectively, all with the addition of polymer. The experimental results led us to conclusion that the adoption of anthracite as single media in deep bed filtration presents the advantage of a lower ascent backwash water velocity for any given bed expansion as compared to deep bed filtration through sand with the same granulometric characteristic. Application of cationic and anionic polymers as filter aids did not lead to any significant improvement in the behavior of pilot scale filters, regardless of applied polymer dosage. Any eventual improvement or worsening was not significant and was closely related to the settled water quality. Regarding the head loss, the filters with anthracite had longer filtration careers when compared to sand, regardless the use of polymers.

A extensa utilização de pesticidas na agricultura moderna tem contribuído para um aumento na contaminação do meio ambiente. Os Hidróxidos Duplos Lamelares (HDLs) ou argilas aniônicas, apresentam uma estrutura lamelar na qual uma variedade de ânions podem ser intercalados entre as lamelas através de interações eletrostáticas. Estes materiais lamelares podem ser utilizados em processos de adsorção/sorção e como suporte para a liberação lenta de compostos químicos. Assim, os principais objetivos deste trabalho foram: o estudo da sorção de ânions orgânicos de herbicidas ácidos 2,4-D, MCPA e Picloram utilizados na agricultura nacional, pela regeneração de HDLs de Mg-Al-CO3 calcinado e por troca aniônica em HDLs de Mg-Al-Cl. Para isso foram investigados a cinética do processo de sorção, além da determinação das isotermas em dois valores diferentes de pH. Assim, estes herbicidas foram intercalados em HDLs de Mg-Al, utilizando dois métodos de síntese indireta: regeneração do material calcinado e troca aniônica em solução, além do método de síntese direta por coprecipitação, sendo os materiais devidamente caracterizados. Todos os materiais obtidos, intercalados com cada um dos herbicidas, foram utilizados para o estudo da cinética de liberação dos mesmos em água. Os materiais obtidos por regeneração contendo cada um dos três herbicidas foram utilizados também no estudo da lixiviação em colunas de solo e no estudo de bio-ensaio com plantas, para testar a eficiência dos HDLs como suportes na liberação lenta dos herbicidas. A partir do estudo da cinética do processo de sorção dos ânions orgânicos presentes em solução utilizando HDLs de Mg-Al contendo cloreto ou carbonato após a calcinação, observou-se que a remoção dos ânions ocorreu através dos processos de troca aniônica no caso do HDL contendo cloreto, ou de regeneração da estrutura lamelar no caso do HDL calcinado. A intercalação dos ânions orgânicos na posição vertical foi verificada no processo de adsorção/sorção, e se mostrou dependente da concentração do herbicida em solução. O HDL calcinado apresentou a maior eficiência na remoção dos ânions da solução. Os herbicidas suportados em HDLs, apresentaram uma liberação em água mais lenta do que os mesmos em sua forma livre, e não se mostrou dependente do método de preparação da matriz utilizada. Os resultados dos estudos de lixiviação utilizando como matriz o HDL obtido por regeneração, demonstraram que os HDLs são bons suportes para os herbicidas pois apresentaram uma liberação lenta do ingrediente ativo, principlamente para o herbicida Picloram. O bio-ensaio mostrou que a forma de liberação dos herbicidas suportados foi eficiente no controle da germinação das sementes de plantas em aplicações pré-emergenciais. / The extensive use of pesticides in modern agriculture has been contributing to an increase in environmental contamination. Layered Double Hydroxides (LDHs), or anionic clays, bear a layered structure, and a variety of anions can be intercalated between these layers through electrostatic interactions. These layered materials can be used in adsorption/sorption processes and in the slow release of chemical compounds. So this work aims at studing the sorption of the acid herbicides bearing organic anions 2,4-D, MCPA and Picloram, used in national agriculture, through regeneration of calcined Mg-Al-CO3 LDH and anion exchange of Mg-Al-Cl ? LDH. For this purpose, the kinetics of the sorption process was investigated, and the determination of isotherms in two different pH values was carried out. The herbicides were intercalated in Mg-Al ? LDH using two indirect synthesis methods: regeneration of the calcined material and anion exchange in solution; besides the direct synthesis method by coprecipitation. The obtained materials were properly characterized. All the obtained materials, intercalated with each of the herbicides, were used in a kinetic release study in water. The materials obtained by regeneration were also used in a leaching and in a bioassay study, to test the efficiency of LDHs as supports for the slow release of herbicides. From the kinetic sorption process of the organic anions in solution using Mg-Al ? LDH containing chloride or carbonate after calcination, it was observed that the removal of anions occurred through an anionic exchange process in the case of the LDH containing chloride, or through regeneration of the layered structure in the case of the calcined LDH. The intercalation of organic anions in a vertical position was observed in the adsorption/sorption process, and it was shown to be dependent on the herbicide concentration in solution. The calcined LDH was the most efficient for removal of anions in solution. The herbicides supported on LDHs, presented a slower release in water than the same compounds in their free form, and the release behavior was not dependent on the methodology used for the preparation of the matrix. Leaching study results using the LDH obtained by regeneration as matrix demonstrated a slow release of the active ingredient, mainly for the Picloram herbicide. The bioassay showed that the release behavior of the supported herbicides was efficient in the control of plant seeds germination at preemergence applications.

L’éclosion de bactéries résistantes aux antibiotiques constitue un problème sérieux auquel fait face notre système de santé. L’une des stratégies récemment proposées afin de s’attaquer efficacement et irréversiblement à ces microorganismes multi-résistants est de cibler directement leur membrane via l’action de molécules induisant un débalancement électrolytique de part et d’autre de cette dernière. Parallèlement, ces mêmes agents peuvent aussi avoir des applications dans le traitement de maladies originant des dysfonctions du transport ionique, comme la fibrose kystique. À cet égard, nous présentons dans cette thèse différents sels d’imidazolium et benzimidazolium N,N-disubstitués possédant un potentiel à la fois antimicrobien et ionophore. Notre approche se résume d’abord en un volet mécanistique où une série de modifications structurelles ont été apportées à des sels d’imidazolium et benzimidazolium afin d’observer comment ces changements modulent l’efficacité du transport d’anions dans la membrane artificielle d’un liposome. Nous avons à ce titre pu conclure que l’espèce formée de deux bras aromatiques phényléthynylbenzyl, disposées symétriquement de part et d’autre d’un cation imidazolium, induisait le meilleur transport des anions chlorures, au travers d’une membrane de liposomes, à des concentrations de l’ordre du micromolaire. En outre, les monocations imidazolium et benzimidazolium flanqués d’un contre-anion bis(trifluorométhylsulfonyl)amide ont conduit à une activité ionophore plus rapide. Qui plus est, en s’appuyant sur ces résultats, nous avons présenté le premier exemple, à notre connaissance, d’un transporteur d’anions et de cations, contenant le cation benzimidazolium et capable d’agir aussi bien dans des liposomes que dans des bactéries. Dans un second temps, les meilleurs agents ionophores ont été étudiés dans les membranes plus complexes des bactéries et des globules rouges humains pour vérifier leur effet bactéricide et leur innocuité. Le design de nos transporteurs formés d’un espaceur luthidine a ainsi permis d’obtenir un agent antimicrobien efficace dans des bactéries gram positives et négatives (B. thuringiensis et E. coli) avec une toxicité limitée de l’ordre de 10% sur les globules rouges humains à ses concentrations bactéricides. / The emergence of antibiotic resistant bacteria is a serious problem that our health system faces. One recently proposed strategy to effectively and irreversibly kill these multi-resistant microorganisms is to directly target the integrity of their membrane, using small molecules able to induce an electrolyte imbalance. Moreover, the same molecules may find applications in the treatement od diseases originating from the dysfunction of ion transport, such as cystic fibrosis. Herein we present different imidazolium and benzimidazolium salts N,N-disubstituted with both antimicrobial and ionophoric potential. We first performed mechanistic studies where different structural changes have been made to the imidazolium and benzimidazolium salts to observe how these modifications modulate the efficiency of the anion transport in artificial membrane liposomes. We were able to conclude that the species formed of two aromatic arms phenylethynylbenzyl arranged symmetrically on either side of an imidazolium cation, induced a better transport of chloride anions, through a membrane of liposomes at the micromolar range. In addition, monocations imidazolium and benzimidazolium flanked with an bis(trifluorométhylsulfonyl)amide anion led to faster ionophore activity. Moreover, based on these results we presented the first example, to our knowledge, for an anions and cations benzimidazolium-based transporter, acting as well in liposomes as in bacteria. Secondly, the best anionophore agents were analyzed in more complex bacterias and human red blood cells membranes to study their bactericidal potential and innocuity. Among all the benzimidazolium salts studied, we identified one compound, which presents interesting antibacterial properties as a result of its ability to induce an electrolytic imbalance and to disrupt the integrity and the potential of the bacterial membranes. At the same time this antibacterial agent presented a low toxicity to human cells in bacteriostatic range concentrations.

O projeto consistiu em avaliar o emprego de polímeros catiônicos e aniônicos de diferentes pesos moleculares como auxiliares de filtração no tratamento de águas de abastecimento proveniente de mananciais com alto grau de eutrofização com vistas a possibilitar a otimização da remoção de material particulado e minimização da evolução da perda de carga. O aparato experimental é composto, principalmente, por 4 filtros em escala piloto de alta taxa do tipo camada profunda e fluxo descendente por gravidade operados em paralelo. Os filtros possuem 5 m de altura e diâmetro interno de 150 mm. O procedimento experimental foi dividido em três etapas, execução de ensaios de fluidificação e expansão do leito dos filtros e utilização de polímeros catiônicos e de polímero aniônico como auxiliares de filtração. A primeira etapa teve como objetivo definir parâmetros de dimensionamento do sistema de lavagem em contra-corrente com ar e água e nas duas etapas seguintes foram realizados os ensaios de filtração a uma taxa de 500 m³/m²/dia, com a utilização dos polímeros com três dosagens diferentes. Os polímeros utilizados foram CA-2577, CA-2581, CD-2592 e N1986. Estes possuem estrutura e pesos moleculares variáveis, de forma que o trabalho tivesse uma maior amplitude. Os valores médios de turbidez, para a primeira etapa dos ensaios de filtração, foram de 2,36 ± 0,28 UNT e 1,12 ± 0,21 UNT para água bruta e decantada, respectivamente, 0,26 ± 0,07 UNT para o filtro F1 com antracito, 0,25 ± 0,08 UNT para o filtro F3 com antracito e adição de polímero, 0,29 ± 0,08 UNT para o filtro F2 com areia e 0,26 ± 0,08 UNT para o filtro F4 com areia e adição de polímero. Para a segunda etapa dos ensaios de filtração os valores médios de turbidez foram de 2,03 ± 0,36 UNT para água bruta, 0,80 ± 0,21 UNT para água decantada, 0,09 ± 0,03 UNT para o filtro F1, sem adição de polímero, e 0,15 ± 0,04, 0,16 ± 0,03 e 0,10 ± 0,04 UNT para os filtros F2, F3 e F4, respectivamente, todos com adição de polímero. Os resultados experimentais possibilitaram concluir que a adoção do antracito como material filtrante do tipo camada única e profunda apresenta a vantagem de permitir uma menor velocidade ascensional de água de lavagem para uma determinada expansão quando comparado a um filtro de areia de idêntica granulometria. A aplicação dos polímeros catiônicos e do polímero aniônico como auxiliares de filtração não proporcionou para nenhuma dosagem utilizada melhora significativa no comportamento dos filtros. Uma eventual melhora ou piora foi insignificante e estava ligada à qualidade da água decantada. No que diz respeito à perda de carga, os filtros com antracito tiveram carreiras de filtração mais longas quando comparados com os de areia, independente da utilização dos polímeros. / The project was to evaluate the use of anionic and cationic polymers of different molecular weights as filter aids to treat drinking water treatment of surface water sources with high degree of eutrophication, particularly with regard to particulate matter removal optimization and head loss rate minimization. The experimental apparatus was composed of four pilot scale, deep bed, down flow rapid gravity filters, operated in parallel. The filter columns were 5 m high, had inner diameter of 150 mm. The experimental procedure was divided in three stages, conduction of media fluidization and media expansion tests and cationic and anionic polymers application as filter aid. The first stage aims was to define design parameters for the filter backwashing system with water and air and in the two next phases the tests were conducted at a filtration rate of 500 m³/m²/day, with the use of polymers with three different dosages. The polymers tested were CA- 2577, CA-2581, CD-2592 and N1986. They have different structure and molecular weights, thus making wider the array of possibilities tested. The average values of turbidity, for the first stage of testing filtration, were 2.36 ± 0.28 and 1.12 ± 0.21 NTU for raw and settled water, respectively, 0.26 ± 0.07 NTU to the filter F1 with anthracite, 0.25 ± 0.08 NTU for the filter F3 with anthracite and addition of polymer, 0.29 ± 0.08 NTU for the filter F2 with sand and 0.26 ± 0.08 NTU for the filter F4 with sand and the addition of polymer. For the second stage of testing of the filter values of turbidity were 2.03 ± 0.36 NTU for raw water, 0.80 ± 0.21 NTU for settled water, 0.09 ± 0.03 for the filter F1, without the addition of polymer, and 0.15 ± 0.04, 0.16 ± 0.03 and 0.10 ± 0.04 NTU for filters F2, F3 and F4, respectively, all with the addition of polymer. The experimental results led us to conclusion that the adoption of anthracite as single media in deep bed filtration presents the advantage of a lower ascent backwash water velocity for any given bed expansion as compared to deep bed filtration through sand with the same granulometric characteristic. Application of cationic and anionic polymers as filter aids did not lead to any significant improvement in the behavior of pilot scale filters, regardless of applied polymer dosage. Any eventual improvement or worsening was not significant and was closely related to the settled water quality. Regarding the head loss, the filters with anthracite had longer filtration careers when compared to sand, regardless the use of polymers.

O presente trabalho trata da preparação e da caracterização de sistemas contendo tetrassulfoftalocianinas de Co(II) (CoPcTs) e Fe(III) (FePcTs) intercaladas ou somente adsorvidas externamente em matrizes de hidróxidos duplos lamelares (HDLs). Foram sintetizados materiais com composições variadas e empregando-se diferentes métodos de síntese visando, principalmente, o isolamento de materiais com microporosidade intracristalina e/ou com um baixo grau de agregação da ftalocianina. Técnicas de caracterização textural (difração de raios-X e medidas de área superficial) e espectroscópicas (vibracional na região do infravermelho, eletrônica no UV/visível, ressonância paramagnética eletrônica e absorção de raios-X), além das análises elementar (C, H, N e metais) e termogravimétrica foram utilizadas para a caracterização dos sólidos sintetizados. Avaliaram-se os materiais como catalisadores na reação de oxidação do 2,6-di-terc-butilfenol e do catecol, utilizando O2ou H2O2 como oxidantes. Nos materiais isolados contendo a CoPcTs intercalada em HDLs com composição MgxAl (x = 2, 3 e 4) e ZnxAl (x = 4 e 5), a ftalocianina está orientada perpendicularmente às lamelas do HDL, independentemente do método de síntese e da composição dos HDLs utilizados. Adicionalmente, constatou-se que a CoPcTs intercalada está altamente agregada e que os materiais não possuem microporosidade. Porém, a diminuição da densidade de carga do HDL provoca uma pequena diminuição na agregação da CoPcTs. Sob determinada condição sintética, a CoPcTs intercalada nos HDLs ZnxAl sofre o processo de enxertia através dos grupos sulfônicos. Quando testados como catalisadores na oxidação do 2,6-di-terc-butilfenol, os materiais contendo a CoPcTs intercalada e enxertada apresentaram reatividade inexpressiva, que pode ser devida ao acesso restrito do substrato ao sítio ativo na região interlamelar. Estudos de adsorção da FePcTs em HDLs MgxAl na forma carbonato, investigados por espectroscopia eletrônica UV/Visível in situ, mostraram uma elevada tendência de agregação da ftalocianina na superfície dos HDLs. Os espectros eletrônicos indicaram também que diferentes espécies derivadas da FePcTs são formadas durante o processo de adsorção nos HDLs e que a densidade de carga influencia o tipo de espécie adsorvida: há predominância de um dímero do tipo µ-oxo nos HDLs Mg2Al e Mg3Al e do dímero (FePcTs)2 no HDL Mg4Al. Os espectros de absorção de raios-X (XANES) da FePcTs adsorvida nos HDLs MgxAl mostraram que as espécies adsorvidas apresentam geometria piramidal de base quadrada (C4v) e/ou octaédrica (Oh), corroborando com os dados de espectroscopia no UV/Visível. Já os espectros de ressonância paramagnética eletrônica mostraram que a ftalocianina de Fe(III) quando adsorvida nos HDLs gera uma mistura de espécies com configuração de baixo spin e alto spin e, também, elevada distorção rômbica. A FePcTs adsorvida nos HDLs MgxAl apresentou estabilidade e reatividade catalítica superior quando comparada com a ftalocianina livre na oxidação dos fenóis. A ftalocianina adsorvida na superfície externa do HDL deve favorecer o acesso do substrato ao sítio ativo. Uma correlação entre os estudos de adsorção e os resultados dos testes catalíticos mostrou que a espécie dimérica do tipo µ-oxo pode ser a espécie mais ativa na oxidação dos fenóis. Nestes sistemas, as camadas positivas do HDL devem provocar um enfraquecimento da ligação O-H do fenol, facilitando a sua desprotonação (uma das etapas do mecanismo de oxidação). Este último efeito pareceu atuante, pois foram observadas reatividades crescentes dos catalisadores à medida que se aumentava a densidade de carga do HDL. Estes resultados indicaram que existe um efeito cooperativo nos HDLs MgxAl contendo a FePcTs adsorvida, mostrando que o HDL não atua como um suporte inerte nos processos estudados. / The present work describes the preparation and characterization of materials containing Co(II) and Fe(III) tetrasulfonated phthalocyanines (CoPcTs and FePcTs, respectively) intercalated or adsorbed on layered double hydroxides (LDHs). Different compositions and synthetic methods were used to isolate materials with microporosity and/or the phthalocyanine in a low aggregation degree. X-ray diffraction analysis, surface area measurements, spectroscopic techniques (infrared, UV/visible and X-ray absorption), elemental analysis and thermogravimetry were used to characterize the solids. The materials were tested as catalysts in the 2,6-di-terc-butilfenol and catechol oxidation, using O2 or H2O2 as oxidants. In the materials prepared by intercalation of the CoPcTs in MgxAl (x = 2, 3 and 4) and ZnxAl (x = 4 and 5) LDHs, the phthalocyanine is perpendicularly orientated related to the LDH layers, regardless of synthetic method or LDH composition used. In addition, it was observed that the intercalated phthalocyanine is aggregated and the solids do not have microporous. However, the aggregation degree of the phthalocyanine is slightly lower when the LDH charge density decreases. Under a particular synthetic conditions the CoPcTs intercalated in the LDH ZnxAl is grafted through the sulfonic groups. Catalytic tests uisng this material in the 2,6-di-terc-butilfenol oxidation showed a neglectful reactivity, which confirms the aggregation of the intercalated CoPcTs, thus avoiding that the substrate accesses the reactive center. In an adsorption study carried by monitoring in situ the FePcTs UV/Vis electronic spectra during its addition to LDH suspensions, a strong tendency of aggregation was observed for the FePcTs. In addition, different FePcTs species are formed during the adsorption process on the LDHs, which is influenced by the LDH charge density: the µ-oxo complex is the main species adsorbed on the Mg2Al and Mg3Al LDHs, whereas for Mg4Al the non oxo-bridged dimeric complex prevailed. X-ray absorption spectra (XANES) of the adsorbed FePcTs on the MgxAl LDHs showed that the species present a square-pyramidal (C4v) and/or an octahedral (Oh) symmetry, in agreement with the UV/visible spectroscopic data. EPR spectra of these samples showed that the FePcTs adsorbed on the LDHs leads to a mixture of Fe(III) high and low spin species along with a strong rhombic distortion. The FePcTs adsorbed on the MgxAl LDHs showed an enhanced catalytic activity and longevity in the phenols oxidation compared to the homogeneous counterpart. The phthalocyanine on the LDH external surfaces allows the access of the substrate to the reactive metal center. A correlation between the adsorption study and the catalytic tests pointed that the FePcTs µ-oxo complex may be the active species in the oxidation of phenols. Furthermore, the positive charge of LDH layers may weaken the O-H bonding in the phenol molecules making them more easily ionized (one step of the phenol oxidation mechanism). This feature seems to be effective because higher activities of the catalysts were observed along with increasing charge density of the LDHs. These results indicated that a cooperative effect takes place in the materials containing the FePcTs adsorbed on the MgxAl LDHs, showing that LDH do not act as an inert support in the studied catalytic reactions.

A invertase comercial (Bioinvert®) foi imobilizada por adsorção em resinas aniônicas do tipo Dowex® [1x8:50-400, 1x4:50-400 e 1x2:100-400, todos copolímeros estireno-divinilbenzênicos, porém de granulometria (50-400 mesh) e quantidades de ligações cruzadas diferentes (2-8%)] em meio aquoso. A melhor percentagem de adsorção da invertase nas resinas foi observada em pH 5,5 a 32°C, tendo o complexo Dowex®1x4-200/lnvertase apresentado índice de adsorção e coeficiente de imobilização iguais a 100%. Os parâmetros cinéticos e termodinâmicos foram determinados para a invertase solúvel e insolúvel de Bioinvert® e também para a invertase purificada (Fluka®). O complexo Dowex®1 x4-200/Bioinvert® apresentou-se estável durante as reações sem desprendimento da enzima do suporte. Os parâmetros termodinâmicos da forma solúvel e insolúvel da Fluka® foram idênticos aos do Bioinvert®, no entanto, após a imobilização apresentou uma redução de 28% na sua atividade. O estudo da atividade transferásica de ambas as formas de Bioinvert® em diferentes concentrações de sacarose foram analisadas através da cromatografia de camada delgada. A estabilidade operacional e de estocagem foi também determinada para o complexo Dowex®1x4-200/Bioinvert®. / The invertase (trademarked as Bioinvert®) solubilized in deionized water was immobilized by adsorption on anion exchange resins, collectively named Dowex®, [1x8:50-400, 1x4:50-400 and 1x2:100-400, styrene-divinylbenzene copolymers, with different granulometry (50-400mesh) and different degrees of cross-linking (2-8%)]. The best percentage of adsorption of invertase on resins was observed in pH 5.5 at 32°C and the complex Dowex®1x4-200/invertase has shown a coupling yield and an immobilization coefficient equal to 100%. The thermodynamic and kinetic parameters for sucrosehydrolysis for both soluble and insoluble enzyme were evaluated to Bioinvert® and purified invertase purchased from Fluka®. The complex Dowex®/Bioinvert® was stable without any desorption of enzyme from the support during the reaction and having the thermodynamic parameters equal to the soluble formo However, the loss of activity for immobilized Fluka® was found to be 28% when compared to the soluble one. The transfructosylating activity of Bioinvert® in both forms in different concentrations of sucrose was investigated through TLC. In regard to insoluble Bioinvert® its storage and operational stability were also determined.

Surfactants are one of the more ubiquitous contaminants in aquatic systems. Their importance as toxic components of pesticide formulations has, however, been largely overlooked. Amphibians particularly, as inhabitants of shallow, temporary and often lentic aquatic environments may be at risk from exposure to these chemicals when they enter aquatic systems. This thesis presents data on the toxicity of surfactants to amphibians. Several experimental exposures were conducted with embryo-larval, tadpole and adult developmental stages of the Australian species- Crinia insignifera, Helcioporus eyrei, Limnodynastes dorsalis and Litoria moorei and the exotic species- Bufo marinus and Xenopus laevis. Animals were variously exposed to glyphosate formulations that contain a high proportion of nonionic surfactants, or commercial pesticide wetting agents (alcohol alkoxylate and nonylphenol ethoxylate (NPE) surfactants). Feeding stage tadpoles of C.insignifera, H. eyrei, L. dorsalis and L. moorei were exposed to three commercial glyphosate formulations, glyphosate isopropylamine and glyphosate acid in static-renewal acute toxicity tests. The 48-h LC50 values for Roundup Herbicide (MON 2139) tested against tadpoles of C. insignifera, H. eyrei, L. dorsalis and L. moorei ranged between 8.1 and 32.2 mg/L (2.9 and 11.6 mg/L glyphosate acid equivalent (ae)), while the 48-h LC50 values for Roundup Herbicide tested against adult and newly metamorphosed C. insignifera ranged from 137-144 mg/L (49.4-51.8 mg/L ae). / Touchdown Herbicide (4 LC-E) tested against tadpoles of C. insignifera, H. eyrei, L. dorsalis and L. moorei was slightly less toxic than Roundup with 48-h LC50 values ranging between 27.3 and 48.7 mg/L (9.0 and 16.1 mg/L ae). Roundup Biactive (MON 77920) was practically non-toxic to tadpoles of the same four species producing 48-h LC50 values of 911 mg/L (328 mg/L ae) for L. moorei and >1000 mg/L (>360 mg/L ae) for C. insignifera, H. eyrei and L. dorsalis. Glyphosate isopropylamine was practically non-toxic producing no mortality amongst tadpoles of any of the four species over 48 h, at concentrations between 503 and 684 mg/L (343 and 466 mg/L ae). The toxicity of technical grade glyphosate acid (48-h LC50, 81.2-121 mg/L) is likely to be due to acid intolerance. Feeding stage tadpoles of B. marinus, X laevis, C. insignifera, H.eyrei, L. dorsalis and L. moorei were exposed to NPE and alcohol alkoxylate in static renewal acute toxicity tests. All species exhibited non-specific narcosis following exposure to both these surfactants. The 48-h EC50 values for NPE ranged between 1.1 mg/L (mild narcosis) and 12.1 mg/L (full narcosis). The 48-h EC50 values for alcohol alkoxylate ranged between 5.3 mg/L (mild narcosis) and 25.4 mg/L (full narcosis). Xenopus laevis was the most sensitive species tested. The sensitivity of the other five species was size dependent with larger species displaying greater tolerance. Replicate acute toxicity tests with B. marinus exposed to NPE at 30 degrees celsius over 96 hours indicated that the narcotic effects were not particularly time dependant. / The mean 24, 48, 72 and 96-h EC50 (mild narcosis) were 3.6, 3.7, 3.5 and 3.5 mg/L respectively. The mean 24, 48, 72, and 96-h EC50 (full narcosis) values were 4.0, 4.1, 4.2 and 4.0 respectively. Acute toxicity tests with B. marinus exposed to NPE at 30 degrees celsius under conditions of low dissolved oxygen (0.8-2.3 mg/L) produced a two to threefold increase in toxicity. The 12-h EC50 values ranged from 1.4 to 2.2 mg/L. The embryotoxicity of NPE was determined in X. laevis, L. adelaidensis and C. insignifera using a Frog Embryo Teratogenesis assay-Xenopus (FETAX). The 96-h LC50, EC50 and MCIG (LOEC) values for X. laevis were 3.9 to 5.4 mg/L, 2.8 to 4.6 mg/L and 1.0 to 3.0 mg/L respectively. The 140-h LC50, ECSO and MCIG values for L. adelaidensis were 9.2 mg/L, 8.8 mg/L and 5.1 to 6.0 ing/L respectively. The 134-h LC50, EC50 and MCIG values for C. insignifera were 6.4 mg/L, 4.5 mg/L and 4.0 mg/L respectively. Teratogenicity indices for the three species ranged between 1.0 and 1.6 indicating either no or low teratogenicity. Xenopus laevis was the more sensitive of the three species and the only species that displayed indisputable terata. The acute toxicity data indicated that the amphibian species tested were of similar sensitivity to fish and some invertebrates. Developmental retardation and oestrogenic effects following exposure to nonylphenol ethoxylate were indicated by sublethal toxicity tests. Crinia insignifera embryos were exposed during early embryogenesis to sublethal concentrations of NPE. / Exposure to NPE did not affect either weight nor size (snout-vent length) at metamorphosis. Exposure to 5.0mg/L NPE resulted in a significant delay in the time required to reach metamorphosis. Also, exposure to 3.0 mg/L NPE for the first 6 days of embryonic development or exposure to 5.0 mg/L NPE from day 2 to day 6 resulted in a statistically significant predominance in the female phenotype amongst metamorphosing froglets. Exposure for the first five days to 1.5 ing/L or 3.0 mg/L NPE had no effect on sex ratio. The results indicated that exposure to NPEs has endocrine disruptive effects in this species and that a narrow window of susceptibility exists for the induction of predominantly female phenotype. This study has also followed the degradation of a mixture of NPE oligomers and the concomitant formation of individual oligomers in static die-away tests with and without illumination in freshwater. Over 33 days in darkness there was a progressive and complete loss of long chain oligomers (NPEO(subscript)8-17), transient increases and subsequent loss of short to medium chain oligomers (NPE0(subscript)4-7), and large persistent increases (approximately 1000%) in short chain oligomers (NPE0(subscript)1-3). In the presence of illumination, biodegradation was retarded and heterotrophic bacterial proliferation was inhibited. After 33 days there was complete loss of long chain oligomers (NPE0(subscript)9-17), incomplete loss of medium chain oligomers (NPE0(subscript)6.8) and increases in short chain oligomers (NPE0(subscript)1-5). / This thesis discusses the importance of persistent metabolites of NPE degradation as it pertains to the habitat, developmental time frame and ecology of amphibians. Degradation of NPE is likely to occur over a time frame that is longer than that required for complete embryogenesis and metamorphosis of many species of amphibians, and may easily encompass those critical stages of development during which oestrogenic metabolites can affect development.