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Nanosensores opticos de polidiacetileno para el reconocimiento de moléculas de interes ambiental y alimentício / Nanosensors optical of polydiacetylene for recognition of molecules of interest environmental and nutritionalCastellon Castrillon, Elkin Dario 29 July 2013 (has links)
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Previous issue date: 2013-07-29 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior, CAPES, Brasil / In this paper we propose the synthesis of an optical nanosensor for the detection of benzene, chlorinated solvents and melamine, novel nanostructures based on polydiacetylene (PDA) that are formed by monomers 10,12-pentacosadiinóico acid (PCDA) self-organized means amphiphilictriblock composed.The effect of the chemical structure and the balance of hydrophobic and hydrophilic triblock copolymers in colorimetric response (CR) of comparing with PCDA/L64 nanoblends PCDA vesicles in the presence of benzene. The UV-vis electronic spectrum shows that the largest intensity of the light absorbed nanoblend is due to a higher yield of the polymerization reaction of the diacetylene monomers nanoblenda that in the vesicle. Possibly due to the intermolecular interaction between benzene and propylene oxides alter the interaction between propylene oxide and PCDA reducing the rotational barrier of the carbon - carbon PCDA molecules allowing color change from blue to red.The effect of the chemical chlorinated structure of the transition colorimetric nanoblends of PCDA/L64. Showing PCDA/L64 nanosensor sensitivity has the same detection limit for chloroform and carbon tetrachloride, and this value close to 10 mM, therefore to dichloromethane is about 15 times greater than or equal to 150 mM. So this is verified nanosensor not specific for any of these chlorinated compounds may then distinguish a range of concentrations between dichloromethane and two chlorinated solvents.Determined the relative contribution of different intermolecular interactions to transition nanoblendas colorimetric PCDA / triblock caused by interaction with molecules of melamine. Showing that keeping the size of the hydrophobic region and the hydrophilic region growing by comparing nanoblends different copolymers, it is verified that the minimum concentration needed for melamine maximum occurs colorimetric transition remains the same, thus the colorimetric transition starts at concentrations melamine under nanostructures higher hydrophilic regions.This new nanosensor was efficient in detecting melamine which is known as a major adulterant of food and organic molecules of high environmental interest. / En este trabajo se propone la síntesis de un nanosensor óptico para la detección de benceno, solventes clorados y melamina, partiendo de nuevas nanoestructuras de polidiacetileno (PDA) que son constituidas por monómeros de ácido 10,12- pentacosadiinóico (PCDA) auto-organizados en medios anfifílicoscompuestos por copolímeros tribloque. Se Investigó el efecto de la estructura química y del balance hidrofóbico e hidrofílico de los copolímeros tribloques en la respuesta colorimétrica (RC) de las nanoblendas PCDA/copolímero tribloque comparándolas con vesículas de PCDA en presencia de benceno. El espectro electrónico ultravioleta- visible muestra que la mayor intensidad de luz absorbida es de la nanoblenda, debido a un mayor rendimiento de la reacción de polimerización de los monómeros de diacetileno en la nanoblenda que en la vesícula. Posiblemente por la interacción intermolecular entre benceno y óxido de propileno alteran la interacción entre óxido de propileno y PCDA reduciendo así la barrera rotacional de los enlaces carbono – carbono de las moléculas de PCDA permitiendo así el cambio de coloración de azul para rojo. Se determinó el efecto de la estructura química de compuestos clorados sobre la transición colorimétrica de las nanoblendas de PCDA/L64. Mostrando que la sensibilidad del nanosensor PCDA/L64 posee el mismo límite de detección para el cloroformo y tetracloruro de carbono, siendo este valor próximo a 10 mmol L -1 , por lo tanto para diclorometano es aproximadamente 15 veces mayor igual a 150 mmolL -1 . Se verifica así que este nanosensor no es específico para ninguno de estos compuestos clorados, pudiendo distinguir un intervalo de concentraciones entre diclorometano y los otros dos solventes clorados. Se determinóla contribución relativa de las diferentes interacciones intermoleculares para la transición colorimétrica de las nanoblendas PCDA/copolímero tribloque causada por interacción con moléculas de melamina. Confirmando que manteniendo el tamaño de la región hidrofóbica y aumentando la región hidrofílica, comparando nanoblendas de copolímeros diferentes, se verifica que la concentración mínima de melamina necesaria para que ocurra la máxima transición colorimétrica permanece igual, por lo tanto la transición colorimétrica se inicia en concentraciones menores de melamina para nanoestructuras con regiones hidrofílicas mayores.Este nuevo nanosensor se mostró eficiente en la detección de melamina que es conocida como un importante adulterante de productos alimenticios y en moléculas orgánicas de alto interés ambiental.
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Solubilização de fármacos em formulações micelares de misturas de copolímetros triblocos / Solubilisation of aromatics drugs in formularizations micelares of mixed of triblock copolymesPinho, Maria 05 September 2006 (has links)
PINHO, M. E. N. Solubilização de fármacos em formulações micelares de misturas de copolímetros triblocos. 2006. 95 f. Dissertação (Mestrado em Química Inorgânica) – Centro de Ciências, Universidade Federal do Ceará, Fortaleza, 2006 / Submitted by irlana araujo (irlanaaraujo@gmail.com) on 2011-12-29T16:18:34Z
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Previous issue date: 2006-09-05 / The aim of this work was to investigate mixed systems of triblock copolymer type E62P39E62 (commercially denoted F87) and E137S18E137 (prepared by oxyanionic polymerization) as novel vehicles for solubilisation and controlled delivery of aromatics drugs The desirable gelation characteristics of solutions of the EmPnEm copolymers with the greater solubilising capacities of solutions of the EmSnEm were investigatedo using an inverted tube test method and by oscillatory rheometry. The structure of the gels was obtained by small angle X-ray scattering (SAXS) and polarized-light microscopy (PLM).The hydrodynamic radius (rh) of the micelle was obtained by dynamic light scattering (DLS). The solubilisation capacity (scp) for the separate copolymers and for mixtures of the two in the range 50/50 to 90/10 wt % E137S18E137/E62P39E62was evaluated by UV-Vis. The fluid/gel boundaries for the copolymers alone and its mixtures were determined by the tube inversion method and confirmed by rheometry. SAXS and PLM for mixture 1 (50/50 wt % E137S18E137/E62P39E62 and for E137S18E137 and E62P39E62 alone) all have shown similar body-centred cubic (bcc) structures with similar lattice dimensions as confirmed by rheology. DLS indicated micelle formation determined by E62P39E62 copolymer. The scp measured for the separate copolymers and its mixtures revealed promise results for application of binary mixtures of copolymer as systems for drug release involving in situ gelation / O objetivo deste trabalho foi investigar misturas de sistemas de copolímeros triblocos do tipo E62P39E62 (comercialmente chamado de F87) e E137S18E137 (sintetizado por polimerização aniônica e denominado de S18) como novos veículos para solubilização e liberação controlada de fármacos. As características desejáveis de gelatinização das soluções do copolímero E62P39E62 combinadas com as capacidades de solubilização das soluções do copolímero E137S18E137 foram estudadas utilizando o método de inversão de tubo e por reologia oscilatória. A estrutura dos géis foi obtida por espalhamento de raios-X a baixos ângulos (SAXS) e por microscopia de luz polarizada (PLM). O raio hidrodinâmico (rh) das micelas foi obtido por espalhamento de luz dinâmico (DLS), e a capacidade de solubilização (scp) dos copolímeros separados e para as misturas dos dois na faixa 50/50 a 90/10 %m/m de E62P39E62/E137S18E137, foi avaliada por espectroscopia de ultravioleta-visível (UV-Vis). Os limites gel/fluido dos copolímeros isolados e suas misturas foram determinados pelo método de inversão de tubo e confirmado por reometria. Os resultados de SAXS e PLM para a mistura 1 (50/50 % m/m E137S18E137/E62P39E62 e para E137S18E137 e E62P39E62 isolados), indicaram estrutura cúbica de corpo centrado (ccc), conforme indicado por reologia. DLS indicou a formação de micelas determinadas pelo copolímero E62P39E62. A scp dos copolímeros e misturas revelou resultados promissores para aplicação de misturas binárias de copolímeros como sistemas de liberação de fármacos envolvendo gelatinização in situ.
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