Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Electroactive textile fibers are key components in smart and interactive textile applications. In previous research on textile base conductive fibers, viscose fibers were coated with poly (3,4-ethylenedioxythiophne) (PEDOT) using oxidative chemical vapor deposition (oCVD) technique[1]. Ferric chloride was used as oxidant and reaction conditions were optimized at which better electrical as well as mechanical properties of conductive viscose fibers could be achieved. In this thesis work, effect of new parameters such as pretreatment of viscose fibers with solvents, drying of oxidant treated viscose fibers at different time and temperature and comparison of two different oxidants have been tried. One new and important oxidant, ferric (III) p-toluene sulfonate or ferric (III) tosylate, used to prepare PEDOT coated viscose fibers and then compared with PEDOT coated viscose fibers prepared using oxidant ferric (III) chloride. Viscose fibers have been treated with two well know solvents, acetone and ethyl acetate before soaking in oxidant solution. Oxidant enriched fibers dried at different temperature for variable time prior to polymerization step. Knitted structures of conductive viscose fibers have been prepared. Hand washing of PEDOT coated viscose fibers with tap water and machine washing of knitted structures according to the international standard ISO EN-6330 have been performed and washing effects were investigated. Effects of all of the above mentioned variables on electromechanical properties of PEDOT coated viscose fibers were studied by using tensile testing, TGA analysis, FTIR spectra and conductivity measurements. Stretch sensing properties of knitted structures; before and after washing, were determined on cyclic tester. The purpose of this study is to enhance the properties of PEDOT-coated viscose fibers by controlling different parameters and to evaluate their usage as stretch sensors as well as to check the washability of PEDOT coated viscose fibers and knitted structures. Better electromechanical properties were achieved on new parameters and PEDOT coated viscose fibers were successfully utilized as stretch sensors. PEDOT coated viscose fibers could have potential to apply in areas such as, military textiles, medical textiles and sensors. / Program: Master programme in Textile Technology

This thesis summarizes the outcome of work performed withthe objective to contribute to the knowledge and development ofthe kraft cooking process using spectrophotometricinterfaces. In kraft cooking, it is desirable to maximize the removal oflignin in the cook without loss of pulp strength. Theselectivity can be improved by exchanging some of the hydrogensulfide ion in the white liquor for polysulfides. Paper Ipresents a spectrophotometric method for in-line monitoring ofthe electrochemical production of polysulfide using anATR-probe for the UV-Vis range. A linear relation existsbetween the ATR-probe response and the concentration ofabsorbing species. Thus the process can be followed by simplemonitoring of a few wavelengths. A spectrophotometric monitoring system using a durableNafion ionomer membrane interface for continuous on-linemeasurement of sulfide and dissolved lignin during kraftcooking has previously been developed by our group. In paperII, the permeation of low molecular weight anions from liquorshaving high ionic strengths through a membrane in Na+ form hasbeen studied. A general relation between penetration and ionsize approximated by molecular weight has been established. Thepenetration of different anions can be explained as a diffusionthrough the winding membrane channels. Further the differentanions transport independently without being interfered by thesample matrix. In light of this validation, we applied the membraneinterface to the determination of anthraquinone-2-sulfonate(AQ-S) in alkaline pulping liquor. In paper III, a simple andrapid spectrophotometric method was developed and implementedon real samples. Interferences from other compounds penetratingthe membrane were minimized by reduction of the penetrated AQ-Sand measurement at 520 nm. This method is quick and can be usedon-line. Further, we extended the method to determination ofanthraquinone (AQ) in pulping liquor (paper IV). Although AQ isregarded as insoluble, it was found that the apparentsolubility of AQ in alkaline solutions increases considerablyin the presence of lignin, reaching 0.14 g/L at 90 oC. Thismakes the calibration of AQ possible. Time-resolvedmeasurements of dissolved AQ in 3 kraft-AQ pulping processeswere performed. The results show that the membrane has great potential aspart of a selective interface in applications where theconcentrations of small anions are to be monitored in mediawith high ionic strength. Keywords: Kraft cooking, On-line, Sulfide, Lignin,Polysulfide excess sulfur, Anthraquinone-2-Sulfonate (AQ-S),Anthraquinone (AQ), Nafion Membrane, UV-Vis, ATR-probe,Spectrophotometric.

<p>This thesis summarizes the outcome of work performed withthe objective to contribute to the knowledge and development ofthe kraft cooking process using spectrophotometricinterfaces.</p><p>In kraft cooking, it is desirable to maximize the removal oflignin in the cook without loss of pulp strength. Theselectivity can be improved by exchanging some of the hydrogensulfide ion in the white liquor for polysulfides. Paper Ipresents a spectrophotometric method for in-line monitoring ofthe electrochemical production of polysulfide using anATR-probe for the UV-Vis range. A linear relation existsbetween the ATR-probe response and the concentration ofabsorbing species. Thus the process can be followed by simplemonitoring of a few wavelengths.</p><p>A spectrophotometric monitoring system using a durableNafion ionomer membrane interface for continuous on-linemeasurement of sulfide and dissolved lignin during kraftcooking has previously been developed by our group. In paperII, the permeation of low molecular weight anions from liquorshaving high ionic strengths through a membrane in Na+ form hasbeen studied. A general relation between penetration and ionsize approximated by molecular weight has been established. Thepenetration of different anions can be explained as a diffusionthrough the winding membrane channels. Further the differentanions transport independently without being interfered by thesample matrix.</p><p>In light of this validation, we applied the membraneinterface to the determination of anthraquinone-2-sulfonate(AQ-S) in alkaline pulping liquor. In paper III, a simple andrapid spectrophotometric method was developed and implementedon real samples. Interferences from other compounds penetratingthe membrane were minimized by reduction of the penetrated AQ-Sand measurement at 520 nm. This method is quick and can be usedon-line. Further, we extended the method to determination ofanthraquinone (AQ) in pulping liquor (paper IV). Although AQ isregarded as insoluble, it was found that the apparentsolubility of AQ in alkaline solutions increases considerablyin the presence of lignin, reaching 0.14 g/L at 90 oC. Thismakes the calibration of AQ possible. Time-resolvedmeasurements of dissolved AQ in 3 kraft-AQ pulping processeswere performed.</p><p>The results show that the membrane has great potential aspart of a selective interface in applications where theconcentrations of small anions are to be monitored in mediawith high ionic strength.</p><p>Keywords: Kraft cooking, On-line, Sulfide, Lignin,Polysulfide excess sulfur, Anthraquinone-2-Sulfonate (AQ-S),Anthraquinone (AQ), Nafion Membrane, UV-Vis, ATR-probe,Spectrophotometric.</p>

Dissociation of gas hydrates has been the primary concern of the oil and gas industry for flow assurance, mainly in an offshore environment. There is also a growing interest in the rapid formation of gas hydrates for gas storage, transport of natural gas and carbon sequestration. In this thesis, we experimentally measure the kinetics of formation and dissociation of methane hydrates and the effect of various anionic and cationic surfactants such as sodium dodecyl sulfate (SDS), cetyl trimethylammonium bromide (CTAB) and alpha olefin sulfonate (AOS) on the association/dissociation rate constants. The importance and necessity of micelle formation in these surfactants has been studied. The effect of foam generation on the rate of formation of these hydrates has also been measured. SDS was found to significantly decrease the induction time for hydrate formation. There was an added decrease in the induction time when a foamed mixture of water and SDS was used. On the other hand CTAB and AOS had an inhibiting effect. The contribution of micelles towards promoting hydrate formation was demonstrated with a series of experiments using SDS. The micelles formed by these surfactants appear to serve as nucleation sites for the association of hydrates. New experimental data is presented to show that some surfactants and the use of foam can significantly increase the rate of hydrate formation. Other surfactants are shown to act as inhibitors. A new experimental setup is presented that allows us to distinguish between surfactants that act as promoters and inhibitors for hydrate formation. / text

Techn. Universiẗat, Diss., 2002--Berlin.

Made available in DSpace on 2016-06-02T19:31:40Z (GMT). No. of bitstreams: 1 1959.pdf: 1033941 bytes, checksum: 78e3218226ae4e1376a101c0d5d8d71f (MD5) Previous issue date: 2008-04-25 / Financiadora de Estudos e Projetos / The main anionic surfactants world widely used are the sodium dodecyl benzene sulfonate (LAS) and sodium dodecyl sulfate (DSS), which are mainly used in the manufacturing of domestic and personal hygiene products. As a consequence of the great and increasing consumption of LAS and DSS there is an increasing wareness regarding the adverse effects of these compounds to the organisms and environment. The present study aimed to evaluate the acute and chronic toxicity of the compounds LAS and DSS to the cladocerans Daphnia similis, Ceriodaphnia dubia and Ceriodaphnia silvestrii. It was also evaluated the toxicity of the water and sediments of four reservoirs and one stream of São Paulo State Analyses of LAS concentrations in the water of these reservoirs were also performed by Liquid chromatography. Acute toxicity tests indicated a value of CE(I)50;48h for LAS of 14.17 mg L-1 to D. similis, 11.84 mg L-1 to C. dubia and 13.51 mg L-1 to C. silvestrii. Significant changes in the viability of the cladoceran offsprings were observed for C. dubia and C. silvestrii exposed to the LAS, with values of CENO equal to 1.0 mg L-1 to C. dubia and 2.5 mg L-1 to C. silvestrii. It was concluded that the maximum permissible concentration of 0.5 mg L-1 surfactants as established by the resolution CONAMA nº. 357/2005 (Brazilian Ministry of Environment) in order to protect aquatic communities is adequate, considering the sensitivity of the native species C. silvestrii. The results of the acute toxicity tests with DSS indicated a CE(I)50;48h value of 12.82; 4.37 and 5.42 mg L-1, for D. similis, C. dubia and C. silvestrii, respectively. A CENO value of 2.0 mg L-1 was obtained in the chronic toxicity tests for C. silvestrii. The surfactant LAS was detected in all the water samples collected in the Lobo (Broa), Lagoa Dourada and Fazzari reservoirs, but at concentrations lower than 5 mg L-1 (the method limit of detection). The toxicity tests with environmental samples revealed that there is no toxicity in the water of the Lobo and Lagoa Dourada sampled, however the water of Monjolinho Reservoir was toxic to D. similis and Fazzari stream was toxic to D. similis and C. dubia. Only the sediment of Monjolinho Reservoir was not toxic to cladocerans. / Os principais surfactantes aniônicos disponíveis no mercado mundial são o dodecil benzeno sulfonato de sódio (LAS) e o dodecil sulfato de sódio (DSS), utilizados principalmente em produtos de limpeza doméstica e de higiene pessoal. Devido ao grande consumo mundial de LAS e de DSS há uma crescente preocupação sobre os efeitos adversos destes compostos no ambiente e aos organismos. Este trabalho teve por objetivo avaliar a toxicidade aguda e crônica do LAS e do DSS aos organismos-teste Daphnia similis, Ceriodaphnia dubia e Ceriodaphnia silvestrii. Foi também avaliada a toxicidade da água e dos sedimentos em quatro reservatórios e um riacho do estado de São Paulo por meio de testes de toxicidade aguda e da análise quantitativa do surfactante LAS. Os testes de toxicidade aguda indicaram uma CE(I)50;48h do LAS de 14,17 mg L-1 para D. similis, 11,84 mg L-1 para C. dubia e 13,51 mg L-1 para C. silvestrii. Nos testes crônicos realizados foi observada significativa alteração viabilidade da progênie de C. dubia e C. silvestrii exposta ao LAS, com valores de CENO igual a 1,0 mg L-1 para C. dubia e 2,5 mg L-1 para C. silvestrii. Pode-se concluir que o valor máximo permissível de surfactantes de 0,5 mg L-1, estabelecido pela Resolução CONAMA nº. 357/2005 em águas destinadas à proteção das comunidades aquáticas, é adequado para a espécie nativa C. silvestrii. Nos testes de toxicidade aguda de DSS foram obtidos valores de CE(I)50;48h de 12,82; 4,37 e 5,42 mg L-1, para D. similis, C. dubia e C. silvestrii, respectivamente. No ensaio de toxicidade crônica obteve-se valor de CENO igual a 2,0 mg L-1 para C. silvestrii. O surfactante LAS foi detectado nas amostras de água dos Reservatórios do Lobo (Broa), Lagoa Dourada e Represa do Monjolinho em concentração inferior a 5 mg L-1. Os testes revelaram que não há toxicidade aguda aos cladóceros da água da Lagoa Dourada e do Reservatório do Lobo, havendo, contudo, toxicidade da água da Represa do Monjolinho para D. similis e da água do Córrego do Fazzari para os cladóceros D. similis e C. dubia. Somente a amostra de sedimento da Represa do Monjolinho não causou toxicidade aos cladóceros.

Grâce à leurs excellentes propriétés mécaniques, électriques et chimiques, les dispositifs organiques électroniques à base de polymères conducteurs peuvent résoudre l’incompatibilité entre les modules électroniques rigides en silicone et les exigences des tissus mous qui constituent l’environnement biologique. Les avancées en matière de semiconducteurs organiques et en microélectronique ont donné naissance à la bioélectronique. Cette discipline emploie des capteurs à des fins diagnostiques, telles que la détection des métabolites ou la mesure d’un potentiel d’action neuronal, et des actionneurs à des fins thérapeutiques, comme l’application locale d’un traitement à l’intérieur même du corps, ou la stimulation cérébrale profonde afin de guérir un trouble neurologique. En bioélectronique, l’utilisation de matériaux organiques, tels que le polymère conducteur poly(3,4-éthylènedioxythiophène) polystyrène sulfonate de sodium (PEDOT:PSS) a permis de développer des composants électroniques biomédicaux de qualité exceptionnelle, comme par exemple le transistor organique électrochimique (OECT), qui ont été testés in vitro et in vivo. Ce manuscrit explique en détail la fabrication, la fonctionnalisation et la caractérisation du OECT à base de PEDOT:PSS. Afin de pouvoir intégrer ce capteur à des systèmes de mesure biomédicaux déjà établis, l’OECT est intégré à des circuits simples, tels qu’un amplificateur de tension ou un pont de Wheatstone. Ces circuits sont mis à l’épreuve de la pratique clinique, dans le cas de mesures électrocardiographiques, ou de détection de métabolites dans des cellules cancéreuses. Cela permet d’apprécier à la fois leur applicabilité, et leurs limites. / Due to their outstanding mechanical, electrical and chemical properties, organic electronic devices based on conducting polymers can bridge the gap between the rigid silicon based read-out electronics and the soft biological environment and will have a huge impact on the medical healthcare sector. The recent advances in the field of organic semiconductors and microelectronics gave rise to a new discipline termed bioelectronics. This discipline deals with sensors for diagnostic purposes, ranging from metabolite detection and DNA recognition all the way to single neuronal firing events, and actuators for therapeutic purposes, through for example active local drug delivery inside the body or deep brain stimulation to cure neurological disorder. The use of organic materials such as the conducting polymer poly(3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT:PSS) in the field of bioelectronics has brought about a variety of outstanding electronic biomedical devices, such as the organic electrochemical transistor (OECT), that have been implemented for both in vitro and in vivo applications. The present manuscript gives a detailed explanation of the fabrication, functionalization and characterization of OECTs based on PEDOT:PSS. To be able to intercept this sensor element with traditional biomedical recording systems, the OECT is implemented into simple circuit layouts such as a voltage amplifier or a Wheatstone bridge. These sensor circuits are then applied to real-life biomedical challenges, such as electrocardiographic recordings or metabolite detection in tumor cell cultures, to demonstrate their applicability as well as their limitations.

The study deals with interactions of polyelectrolytes polystyrene sulfonate and hyaluronic acid with nitrogenic amphiphilic substances, represented by lysine and albumine. To study the interactions pH-metry, conductance, viscositic and turbidity measurement, DLS and reometry were used. All mixtures of different concentrations were measured and the data were compered with data obtained from measurement of samples with amphiphilic sumstances without polyelectrolytes. Observed interactions occured in the aminoacid concentrations between 0 to 20 mmoldm-3, then the PSS interaction groups were fully bonded by lysine and no more interactions were recognized. The same behaviour were observed in albumine solutions with concentration under 2 gdm-3.

This thesis is focused on investigation of phospholipid-hyaluronan system. First, appropriate method for preparation of bulk solution of phospholipid/lipid and suitable fluorescence probe were chosen. Sonification was selected as a method for preparation of bulk solution and pyrene was chosen as a fluorescence probe. From the group of phospholipids lecithin was selected. Next to phospholipid, lipid with no phosphate group (DPTAP) was utilized for comparison, alternatively a mixture of lipid (DPTAP) and phospholipid (DPPC). Instead of hyaluronan another polyelectrolytes (sodium polystyrene sulfonate, sodium alginate) were used too. Measurements were performed in water environment and in phosphate buffer saline (PBS). All investigation was accomplished by fluorescence spectroscopy and dynamic light scattering.