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Orientador: Ivo Milton Raimundo Junior / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-10T14:29:52Z (GMT). No. of bitstreams: 1 Silva_KarimeRitaBentesda_D.pdf: 987159 bytes, checksum: fbf95cdeef4cddf9f7dda16d5efcb700 (MD5) Previous issue date: 2007 / Resumo: Foram construídos optodos para a determinação de SO2 em amostras de ar e de vinho, com base no cromóforo Pd2(dppm)2Cl2 [(bisdifenilfosfinometano-dicloreto de paládio (I)] imobilizado em matrizes de PVC [poli(cloreto de vinila)] e plastificadas com o-NPOE [o-nitrofeniloctiléter]. As membranas que apresentaram os melhores resultados continham 20% de PVC, 4% do cromóforo e 76% de o-NPOE, para uma massa final de 100 mg. Para amostras de ar, as membranas foram preparadas pela deposição de 200 mL de solução em filmes de poliéster, apresentando espessura média de 500 mm, faixa linear de resposta de 0-5 ppmv SO2, limite de detecção de 130 ppbv SO2 e tempo de vida útil de 2 meses ou 250 medidas. Esse optodo responde também para monóxido de carbono, na faixa linear de 1-5% de concentração. Para amostras de vinhos, as membranas foram preparadas pela deposição manual de 10 mL de solução em filmes de poliéster e foram obtidas faixas lineares de trabalho de 0-50 mg L para SO2 livre e 0-150 mg L para SO2 total, com limites de detecção da ordem de 0,37 e 0,70 mg L, respectivamente. Na validação do método, foi observada uma boa correlação com o método padrão, não havendo diferença significativa no nível de 95% de confiança. Observou-se que sacarose e etanol geram efeito de matriz. Para ambos os optodos, observou-se que é grande o efeito da umidade. Na presença de NO2, H2S, HCl e Cl2 10 ppmv a fase sensora é inutilizada. Também foi desenvolvido um optodo para a determinação de oxigênio dissolvido com base no fluoróforo PtOEP [octaetilporfirinato de platina] imobilizado em PDMS [poli(dimetilsiloxano)]. Os melhores resultados foram obtidos para as membranas preparadas a partir de uma solução contendo 8 x 10 mol L de PtOEP e 20% de sílica. A espessura média das membranas foi de 0,22 ± 0,02 mm. Foi obtido um limite de detecção de 0,077 mg L de O2 dissolvido e com desvio padrão relativo de 0,53%. A faixa linear de resposta foi de 0,07-5,95 mg L de O2 dissolvido em água. Observou-se que não há erro sistemático com o uso deste optodo, e que o mesmo pode ser empregado na determinação oxigênio dissolvido em amostras reais / Abstract: Optodes for determination of sulphur dioxide in air and wine samples were constructed, based on the dichloro-bis-(diphenylphosphino)-methane dipalladium I [Pd2(dppm)2Cl2] complex immobilised in PVC films, plasticised with onitrophenyloctylether [o-NPOE]. The sensing phase that presented best performance was prepared from a THF solution (1 mL), containing 20 mg PVC, 4 mg Pd complex and 76 mg o-NPOE. For air sample analysis, membranes were prepared by the deposition of 200 µL of the cocktail solution on polyester sheet (average thickness of 500 µm), presenting a linear response range of 0-5 ppmv SO2, detection limit of (0.13 ± 0.02) ppmv SO2 and lifetime of 2 months or 250 measurements. This optode also presented a linear response to carbon monoxide in the 1-5 % range. For wine samples, membranes were prepared by the manual deposition of 10 µL of the cocktail solution on polyester sheet, presenting linear response ranges of 0 -50 mg L for free SO2 and 0 -150 mg L for total SO2, with detection limits of 0.37 and 0.70 mg L, respectively. The results showed good correlation with the reference method, presenting no significant differences at the 95 % confidence level. It was observed that sucrose and ethanol affects slightly the sensitivity. For both optodes, it was observed a significant effect of the humidity, as well as poisoning by NO2, H2S, HCl and Cl2 10 ppmv. It was also developed an optode for determination of dissolved O2, based on the fluorophore platinum octaethylporphyrin [PtOEP] immobilised in polydimethylsiloxane [PDMS]. The membrane prepared from a solution containing 8 x 10 mol L PtOEP and 20 % silica presented the best performance, with an average thickness of 0.22 ± 0.02 mm. The optode showed a detection limit of 0.077 mg L dissolved O2, relative standard deviation of 0.53 % and a linear response range from 0.07 to 5.95 mg L O2. It was not observed a systematic error for the developed sensor, which can be applied to the determination of dissolved oxygen in water samples / Doutorado / Quimica Analitica / Doutor em Ciências

Orientadores: Ivo Milton Raimundo Junior, Maria Fernanda D'Oliveira Pimentel / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Quimica / Made available in DSpace on 2018-08-13T12:57:52Z (GMT). No. of bitstreams: 1 Lima_KassioMichellGomesde_D.pdf: 3376040 bytes, checksum: c43fc17e739fb3c24ee4fa1b849c70ef (MD5) Previous issue date: 2009 / Resumo: Este trabalho descreve o desenvolvimento de sensores ópticos para determinação de benzeno, tolueno, etilbenzeno e xilenos (BTEX) e de íons metálicos em águas. Para a determinação de BTEX, monolitos de polidimetilsiloxano (PDMS) foram colocados dentro de um frasco preenchido com soluções aquosas dos compostos BTEX por um determinado tempo. Em seguida, a fase sensora era removida da solução, seca rapidamente e inserida num sistema de medidas, empregando-se um espectrofotômetro FT-NIR. Limites de detecção de 0,079; 0,12; 0,14 e 0,28 mg L para benzeno, tolueno, etilbenzeno e xilenos foram alcançados. A fase sensora foi aplicada a amostras de águas contaminadas por gasolina, quantificando teores de BT (benzeno e tolueno) sem diferença estatística, no nível de 95% de confiança, comparada a técnica GC-FID. A fase sensora também foi usada na determinação simultânea de BTX. Valores de RMSEP (raiz quadrada do erro médio quadrático de previsão) de 0,57 mg L para benzeno, 2,21 mg L para tolueno e 1,23 mg L para xilenos foram alcançados. Um fotômetro no infravermelho próximo baseado em LED (diodos emissores de luz) para a determinação de BTEX total foi desenvolvido. O instrumento desenvolvido opera com dois LED, um fotodiodo, um sistema de fibras ópticas para captação da radiação, célula de transmissão e um programa em Visualbasic.Net para controle e aquisição de dados. O instrumento pode ser uma alternativa viável, de baixo custo para a determinação de BTEX total em águas. Foi avaliado o comportamento do novo reagente luminescente di(hexafluorofosfato) de bis(1,10-fenantrolina)(2-(1H-imidazo[4,5- f][1,10]fenantrolina)Rutenio (II), abreviadamente [Ru(phen)2iip](PF6)2, no desenvolvimento de um sensor óptico para a determinação de íons metálicos em águas. A imobilização do reagente em matrizes poliméricas revelou que o sensor óptico e seletivo ao íon Cu(II), apresentando limite de detecção 32 mg L. O novo complexo de rutênio (II) foi aplicado numa determinação simultânea dos íons metálicos Cu(II) e Hg(II) em solução aquosa, alcançando valores de RMSEP de 2,12 mg L e 0,95 mg L, respectivamente / Abstract: This work describes the development of optical sensors for determination of benzene, toluene, ethylbenzene and xylenes (BTEX) and metal ions in water. For the determination of BTEX, monoliths of polydimethylsiloxane (PDMS) were inserted into a bottle filled with aqueous solutions of BTEX compounds for a pre-defined period of time. Afterwards the sensing phase was removed from the solution, dried and placed in the detection system of an FT-NIR spectrophotometer. Detection limits of 0.079, 0.12, 0.14 and 0.28 mg L for benzene, toluene, ethylbenzene and xylenes, respectively, have been achieved. The sensing phase was applied to the determination of benzene and toluene in water samples contaminated by gasoline, providing results that did not show statistical differences from those obtained by GC-FID at a confidence level of 95%. The sensing phase was also applied to the simultaneous determination of BTX in contaminated water, providing RMSEP values (root mean square error of prediction) of 0.57 mg L for benzene, 2.21 mg L for toluene and 1.23 mg L for xylenes. A near infrared photometer based on LED (light emitting diodes) for the determination of total BTEX was developed. The instrument operates with two LED as light sources and a photodiode as detector, a transmission cell connected to an optical fiber bundles; a VisualBasic.Net program was written for control and data acquisition. The instrument performance indicated that it can be a feasible and low cost alternative for the determination of total BTEX in water. Finally, it was evaluated the performance of the new luminescent reagent bis(1,10-phenanthroline)(2-(1H-imidazol-2- yl)-1H-imidazo[4,5-f][1,10]phenanthroline)ruthenium(II) di(hexafluorophosphate) for the development of an optical sensor for the determination of metal ions in water. The immobilization the reagent in the polymeric matrices showed that the optical sensor is selective to Cu (II) ion, providing a detection limit of 32 mg L. The new complex of ruthenium (II) was also applied to the simultaneous determination of Cu (II) and Hg (II) in aqueous solution, showing RMSEP values 2.12 mg L and 0.95 mg L, respectively / Doutorado / Quimica Analitica / Doutor em Ciências

Les travaux de thèse ont porté sur l'étude de la complexation de métaux lourds par des molécules supramoléculaires qui offrent un moyen facile de détection de ces polluants qui présentent un caractère de toxicité élevé (mercure, plomb, cadmium…..) et sont des polluants des eaux courants. Le durcissement des réglementations concernant les seuils admissibles de polluants nécessite la mise au point de moyens de détection sensibles et de mise en œuvre facile associée à un coût réduit. L’étude est basée sur une famille de calixarènes modifiés par un groupe azoïque qui permet une détection visuelle directe de la présence de métaux lourds par un changement de couleur. Une première étape a porté sur la caractérisation des changements de propriétés optiques (couleur: absorption optique, mais aussi fluorescence) induite par l'ajout des cations métalliques à une solution des calixarènes qui a permis de valider la pertinence du protocole expérimental. Une deuxième étape a porté sur la réalisation des couches minces de calixarènes sur un support pour la réalisation de capteurs optiques. La possibilité de détection en phase dense a pu être démontrée. La détection par fluorescence des sondes calixarènes s'est avérée particulièrement intéressante pour le développement de capteurs chimiques parce que d'une part le signal est bien isolé et d'autres part en raison de la grande sensibilité de cette réponse. La troisième étape a porté sur la réalisation et l'optimisation d’un capteur chimique à réponse optique. Deux types de récepteurs calixarènes aptes à détecter des polluants, révélés par un changement de couleur caractéristique lors d’une simple immersion dans une eau à analyser, ont ainsi pu être sélectionnés / The thesis focused on the study of the complexation of heavy metals by supramolecular that provide an easy way of detecting these pollutants of a high toxicity (mercury, lead, cadmium ...). The tightening of regulations on allowable levels of pollutants requires the development of sensitive detection means and easy implementation associated with a reduced cost. The study is based on a family of calixarenes modified with an azo group which allows direct visual detection of the presence of heavy metals by a color change. The first phase focused on the characterization of changes in optical properties (color: optical absorption, but also fluorescence) induced by the addition of metal cations to a solution of calixarenes which validate the relevance of the experimental protocol. A second stage involved the realization of thin film on a support of calixarenes for producing optical sensors. The possibility of detecting dense phase has been demonstrated. Fluorescence detection probes calixarenes was particularly interesting for the development of chemical sensors because on the one hand the signal is isolated and on the other hand due to the high sensitivity of this response. The third stage involved the implementation and optimization of a chemical sensor optical response. Two types of receptors calixarenes able to detect pollutants, revealed by a characteristic color change in a simple immersion in a water sample, were able to be selected

Two examples of our biophotonic research utilizing nanoparticles are presented, namely laser-based fluoroimmuno analysis and in-vivo optical oxygen monitoring. Results of the work include significantly enhanced sensitivity of a homogeneous fluorescence immunoassay and markedly improved spatial resolution of oxygen gradients in root nodules of a legume species.

Orientadora: Maria del Pilar Taboada Sotomayor / Banca: Denis Ricardo Martins de Godoi / Banca: Éder Tadeu Gomes Cavalheiro / Resumo: Este trabalho propõe a síntese de MIP usando como molécula molde, ou template, o corante Verde Ácido 16 (AG16), um corante do grupo dos trifenilmetanos. A síntese foi feita pelo método em bulk; diretamente sobre a fibra óptica, usada como transdutor no desenvolvimento do sensor óptico; e também diretamente em placas de vidro, para fins de caracterização morfológica dos materiais impressos. O polímero sintetizado e o sensor construído foram caracterizados por Microscopia Eletrônica de Varredura (MEV), Espectroscopia vibracional da região no Infravermelho (IV), Reflectância Total Atenuada (RTA) e Microscopia Confocal. Os parâmetros otimizados para o desempenho do sensor foram temperatura, tempo de adsorção/pré-concentração e pH, obtendo-se os melhores resultados a 25 ºC, 60 minutos e pH 7,0; respectivamente. Sob estas condições os limites de detecção e quantificação do MIP-sensor foram 62,2 e 188 µmol L-1 respectivamente, com valores de repetibilidade e reprodutibilidade, em termos do desvio padrão relativo (RSD) abaixo de 4%. Nos experimentos realizados usando o MIP-optodo-AG16 na presença de outros quatro corantes diferentes, os valores de obtidos para a retenção/adsorção desses corantes mostraram a excelente seletividade do tip-sensor construído. Na aplicação em amostras de rio e de efluente industrial enriquecidas com AG16, os valores de recuperação obtidos foram próximos a 100% para o MIP-optodo, mostrando a eficiência do sensor em relação ao NIP-optodo. Desta forma, este ... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work proposes the synthesis of a MIP using Acid Green 16 (AG16) dye as template molecule of the triphenylmethane group. The synthesis was made by bulk method directly on the optical fiber surface which is using as a transducer in the development of optical sensor and also synthesized directly on glass plates for morphological characterization of the printed materials. The synthesized polymer and the constructed sensor were characterized by Scanning Electron Microscopy (SEM), Infrared (IR), Attenuated Total Reflectance (ATR) and Confocal Microscopy. The optimized parameters were temperature, adsorption/pre-concentration time, pH, obtaining the best results at 25 ºC, 60 minutes and pH 7,0 respectively. Under these conditions for the MIP-sensor the limits of detection and quantification were 62.2 and 188 μmol L-1 respectively, with repeatability and reproducibility values in terms of relative standard deviation (RSD) below 4%. The experiments were performed using MIP-optode-AG16 in presence of four other different dyes and the values obtained for the retention/adsorption of those dyes showed the excellent selectivity of the constructed tip-sensor. For application the river samples and industrial effluent were enriched with AG16 and recovery values were obtained close to 100% for the MIP-optodo that showing the efficiency of the sensor in relation to the NIP-optodo. Thus this master's work shows the development of an exceptional optical sensor for the literature with excelle... (Complete abstract click electronic access below) / Mestre

University, Diss., 2003--Regensburg. / Erscheinungsjahr an der Haupttitelstelle: 2003.

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Carbon dioxide sequestration is one of many mitigation tools available to help reduce carbon dioxide emissions while other disposal/repurposing methods are being investigated. Geologic sequestration is the most stable option for long-term storage of carbon dioxide (CO2), with significant CO2 trapping occurring through mineralization within the first 20-50 years. A fiber optic based monitoring system has been proposed to provide real time concentrations of CO2 at various points throughout the geologic formation. The proposed sensor is sensitive to the refractive index (RI) of substances in direct contact with the sensing component. As RI is a measurement of light propagating through a bulk medium relative to light propagating through a vacuum, the extraction of the effects of any specific component of that medium to the RI remains very difficult. Therefore, a requirement for a selective barrier to be able to prevent confounding substances from being in contact with the sensor and specifically isolate CO2 is necessary. As such a method to evaluate the performance of the selective element of the sensor was investigated. Polybenzimidazole (PBI) and VTEC polyimide (PI) 1388 are high performance polymers with good selectivity for CO2 used in high temperature gas separations. These polymers were spin coated onto a glass substrate and cured to form ultra-thin (>10 μm) membranes for gas separation. At a range of pressures (0.14 –0.41 MPa) and a set temperature of 24.2±0.8 °C, intrinsic permeabilities to CO2 and nitrogen (N2) were investigated as they are the gases of highest prevalence in underground aquifers. Preliminary RI testing for proof of concept has yielded promising results when the sensor is exposed exclusively to CO2 or N2. However, the use of both PBI and VTEC PI in these trials resulted in CO2 selectivities of 0.72 to 0.87 and 0.33 to 0.63 respectively, for corresponding feed pressures of 0.14 to 0.41 MPa. This indicates that both of the polymers are more selective for N2 and should not be used in CO2 sensing applications as confounding gas permeants, specifically N2, will interfere with the sensing element. / Graduate / 0428 / 0495 / 0542 / ben.t.davies@gmail.com