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Fonctionnalisation anti-bactérienne passive ou active de tissus textiles par voie sol-gel ou photochimique - L'association du TiO2 et de la chimie douce / Antibacterial functionalization of textile fabrics through sol-gel routesMessaoud, Mouna 11 February 2011 (has links)
Au cours de cette thèse, plusieurs approches de fonctionnalisation anti-bactérienne passive, de type"bactériostatique" utilisant des espèces hydrophobes, et active (selon un standard ISO), de type"bactéricide" utilisant des nanoparticules d’argent métallique ou des espèces à base d’ammoniumquaternaire, ont été testées sur des tissus textiles. Des solutions liquides ont été élaborées par voie sol-gelet photochimique, en association ou non. Elles ont tout d’abord été caractérisées d’un point de vuephysico-chimique, morphologique et structural, afin d’optimiser leur formulation et les caractéristiquesdes espèces en solution vis-à-vis de différents cahiers des charges industriels. Ce travail d’optimisation aen particulier conduit à des solutions stables permettant leur utilisation reproductible au cours du temps.Les solutions ont ensuite été imprégnées sur des échantillons textiles, par un dispositif simplifié de "padcoating"mis au point au cours de la thèse, afin de tester la fonction anti-bactérienne des textiles traités.Selon la nature des espèces imprégnées, l’optimisation des solutions conduit à une fonctionnalité antibactériennepassive ou active respectant l’aspect visuel du textile et ne dénaturant pas son toucher. Destests de lavage de laboratoire ou de lavage ménager en conditions réelles ont également montré unaccrochage notable des espèces imprégnées sur les textiles. Des options ont finalement été proposées pouraccroître cet accrochage afin de répondre à des conditions de lavage industriel. En conclusion, ce travail met en évidence le potentiel des approches d’élaboration par chimie douce en vue de fonctionnaliser des textiles, en permettant en particulier de proposer des méthodologies originales et simplifiées en adéquation avec des impératifs industriels. / In this thesis, several approaches have been tested for the passive ("bacteriostatic") and active (as definedby an ISO standard, "bactericidal") anti-bacterial fonctionalization of textile fabrics by using hydrophobicspecies and nanoparticles of metallic silver or quaternary ammonium species, respectively. Liquidsolutions were prepared by sol-gel and photochemistry methods, in association or not. Physicochemical,morphological and structural characterizations have first been realized to optimize the solutionformulations and the characteristics of active species in solutions towards various industrialspecifications. This optimization study has in particular led to stable solutions allowing their use inreproducible conditions over time. The optimized solutions were then imparted to textile samples, using asimplified "pad-coating device implemented during the thesis, in order to test the anti-bacterial functionof treated textiles. Depending on the nature of the species present on textiles, the optimized solutions ledto a passive or active anti-bacterial function while keeping the visual aspect and hand feeling of textiles.Laboratory washing tests or laundering washings in real conditions also showed a significant attachmentof impregnated species on textiles. Different options have finally been proposed to enhance thisattachment in order to fulfill industrial washing criteria. In conclusion, this thesis work highlights thepotential of soft chemistry approaches to functionalize textiles supports and enable us to propose originaland simplified methodologies in adequacy with industrial requirements.
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Sol-gel Resorcinarene Sorbent for Capillary Microextraction Coupled to Gas ChromatographyAlhendal, Abdullah Awadh 01 January 2011 (has links)
For the first time, octahydroxyl methylresorcinarene with four hexyl groups on the lower rim was utilized in the in-situ preparation of a silica-based sol-gel organic-inorganic hybrid coating for sample preconcentration by capillary microextraction (CME). Tetraethoxysilane (TEOS) was chosen as a sol gel precursor to create a cross-linked sol-gel network via acid-catalyzed hydrolytic polycondensation reactions. Sol-gel chemistry helped in the in situ preparation of resorcinarene-containing extraction phase in the form of a surface coating. It also provided an effective means to chemically bind the coating to the inner surface of fused silica capillary via condensation of the hydroxyl groups in the sol-gel network with the silanol groups on the fused silica capillary inner surface. These chemically bonded sol-gel coatings demonstrated excellent thermal stability (up to 350 oC). The sol-gel resorcinarene coatings successfully extracted traces of polycyclic aromatic hydrocarbons (PAHs), ketones, phenols, amines, and alcohols from aqueous samples providing parts per trillion level detection limits (0.828 - 46.01 ng/L) in GC using a Flame Ionization Detector (FID). CME was performed by passing the aqueous samples through the resorcinarene coated microextraction capillary (10 cm). The extracted analytes where then thermally desorbed into the GC column connected to the exit end of the sol-gel microextraction capillary via a press-fit quartz connector. Peak area relative standard deviation (RSD %), a measure of the extraction performance reproducibility for the coated capillary, was found in the range of (1.1 % - 8.3 %). The sol-gel resorcinarene sorbent was characterized by FTIR spectrum which indicated the presence of hydroxyl groups in the coating even after the sol-gel reactions were completed which explains the affinity of the resorcinarene sol-gel coating toward polar analytes. Scanning Electron Microscopy (SEM) images of the coating reveraled the porous morphology and thickness of 3.5 - 4.0 µm for the coating. The sol-gel resorcinarene coated capillary provided excellent extraction performance for wide range of analytes.
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Skin Health Monitoring Sensor on Textiles : Incorporation of pH Responsive Dyes on Polyethylene and Polypropylene NonwovensBiswas, Tuser January 2016 (has links)
Incontinence diapers or disposable absorbent pads provide essential help to people having such a physical difficulty. However, during prolonged used of these products in daily life, the skin inside pad area may get fragile and damaged which are difficult to recover in old ages. Therefore a skin friendly sensor can be added to the inner layer of pad that would monitor the skin condition and signal any abnormalities to the wearer. Smart materials which can change color upon variation of skin pH were incorporated with synthetic nonwoven layers of the pad. Among various incorporation methods of these materials, ‘sol-gel’ coating technique was found to be successfulfor applications on optical sensor and on fewother fabric types. Thus ‘sol-gel’ method with modified recipe for different dye and chemical combinations were experimented in this project.Several developed samples showed color change (e.g. yellow to red) that can be easily detected by wearers’ eyes.Additionally, the methods and materials involved showed no adverse effect on health and environment. Thus this study succeeds to provide with a mean for skin health monitor based on nonwoven textiles by incorporation of color changing materials.
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Bioresorbable Magnesium-Based Bone Fixation Hardware: Alloy Design, Post-Fabrication Heat Treatment, Coating, and ModelingIbrahim, Hamdy, Ibrahim January 2017 (has links)
No description available.
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Conformal Coating and Shape-preserving Chemical Conversion of Bio-enabled and Synthetic 3-Dimensional NanostructuresJiaqi Li (9529685) 16 December 2020 (has links)
<p>Impressive examples of the generation of hierarchically-patterned, three-dimensional (3-D) structures for the control of light can be found throughout nature. <i>Morpho rhetenor</i> butterflies, for example, possess scales with periodic parallel ridges, each of which consists of a stack of thin (nanoscale) layers (lamellae). The bright blue color of <i>Morpho</i> butterflies has been attributed to controlled scattering of the incident light by the lamellae of the wing scales. Another stunning example is the frustule (microshell) of the <i>Coscinodiscus wailesii</i> diatom, which is capable of focusing red light without possessing a traditional lens morphology. The photonic structures and the optical behaviors of <i>Morpho</i> butterflies and <i>Coscinodiscus wailesii</i> diatoms have been extensively studied. However, no work has been conducted to shift such light manipulation from the visible to the infrared (IR) range via shape-preserving conversion of such biogenic structures. Controlling IR radiation (i.e., heat) utilizing biogenic or biomimetic structures can be of significant utility for the development of energy-harvesting devices. In order to enhance the optical interaction in the IR range, inorganic replicas of biogenic structures comprised of high-refractive-index materials have been generated in this work. Such replicas of <i>Morpho</i> <i>rhetenor</i> scales were fabricated via a combination of sol-gel solution coating, organic pyrolysis, and gas/solid reaction methods. Diatomimetic structures have also been generated via sol-gel coating, gas/solid reaction, and then patterning of pore arrays using focused ion beam (FIB) milling.</p> Throughout the sol-gel solution coating and chemical conversion steps of the processes developed in this study, attention was paid to preserve the starting shapes of the nanopatterned, microscale biogenic or biomimetic structures. Factors affecting such shape preservation included the thicknesses and uniformities of coatings applied to the biogenic or biomimetic templates, nano/microstructural evolution during thermal treatment, and reaction-induced volume changes. A conformal surface sol-gel (SSG) coating process was developed in this work to generate oxide replicas of <i>Morpho rhetenor</i> butterfly scales with precisely-controlled coating thicknesses. The adsorption kinetics and relevant adsorption isotherm of the SSG process were investigated utilizing a quartz crystal microbalance. Analyses of thermodynamic driving forces, rate-limiting kinetic steps, and volume changes associated with various chemical reactions were used to tailor processing parameters for optimized shape preservation.
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