The production of polyethylene terephthalate (PET) textiles, commonly known as polyester, is an energy and water-intensive process, particularly during the dyeing and finishing stages, leading to significant carbon emissions and wastewater filled with toxic chemicals. Conventional dyeing processes consume large volumes of water and energy, making them environmentally harmful. Innovative methods like hydraulic spray atomizer offer a more sustainable alternative by reducing water and chemical usage, thus minimizing waste and environmental impact. This study explores the hydraulic spray dyeing process parameters, including pre-treatment, dyeing, pre-drying, and fixation steps for three different polyester fabrics. The objective is to achieve resource-efficient dyeing with comparable results to traditional methods, and to compare effectiveness of a combined pre-treatment and dyeing approach with a two-step spray application of pre-treatment and dyeing. Pre-treatment of the polyester fabrics with chemical hydrophilizing agents by spray application showed to improve the hydrophilic character and wetting capacity of three polyester fabrics—P75, P600, and Kibo based on reduced water contact angle measurements and increased vertical wicking rates. A pre-treatment also showed to enhance the K/S values of the three different polyester fabrics. The addition of a pre-drying step showed some indication of reducing disperse dye migration, and enhanced color strength of the Kibo fabrics. Spray dyed samples maintained dyeing quality comparable to padded samples. One-step spray processes demonstrated comparable or improved color properties and durability to fastness to washing and abrasion in comparison to two-step processes. The results demonstrate that the hydraulic spray atomizing system is viable for both dyeing and pre-treatment of polyester fabrics. Furthermore, this lays the groundwork for innovation in wet textile processes of polyester fabrics using this resource-efficient alternative, aiming towards sustainable textile production and dyeing.

Chemische und physikalische Eigenschaften von Polymeren können verschiedene Zelltypen unterschiedlich, z. B. hinsichtlich Adhärenz oder Funktionalität, beeinflussen. Die Elastizität eines Polymers beeinflusst vor allem, welche Zugkräfte eine Zelle gegenüber ihrem Substrat entwickeln kann. Das Zellverhalten wird dann über intrazelluläre Rückkopplungsmechanismen reguliert. Die Oberflächenladung und/oder Hydrophilie eines Polymers beeinflusst zunächst die Adsorption von Ionen, Proteinen und anderen Molekülen. Vor allem über die Zusammensetzung, Dichte und Konformation der adsorbierten Komponenten werden anschließend die Wechselwirkungen mit den Zellen vermittelt. Des Weiteren können verschiedene Zelltypen unterschiedliche membranassoziierte Proteine, Zucker und Lipide aufweisen, so dass Polymereigenschaften zellspezifische Effekte bewirken können. Für biotechnologische Anwendungen und für den Einsatz in der regenerativen Medizin gewinnen Polymere, die spezifische Zellreaktionen regulieren können, immer weiter an Bedeutung. Die Isolierung und Kultur von primären Keratinozyten ist noch immer anspruchsvoll und die adäquate Heilung von Hautwunden stellt eine fortwährende medizinische Herausforderung dar. Ein Polymer, das eine bevorzugte Adhärenz von Keratinozyten bei gleichzeitig verminderter Anheftung dermaler Fibroblasten ermöglicht, würde erhebliche Vorteile für den Einsatz in der Keratinozyten-Zellkultur und als Wundauflage bieten. Um den potentiell spezifischen Einfluss bestimmter Polymereigenschaften auf primäre humane Keratinozyten und dermale Fibroblasten zu untersuchen, wurde in der vorliegenden Arbeit ein Zellkultursystem für die Mono- und Cokultur beider Zelltypen entwickelt. Das Testsystem wurde als Screening konzipiert, um den Einfluss unterschiedlicher Polymereigenschaften in mehreren Abstufungen auf die Zellen zu untersuchen. Folgende Parameter wurden untersucht: 1. Vitalität und Dichte adhärenter und nicht-adhärierter Zellen, 2. Schädigung der Zellmembran, 3. selektive Adhärenz von Keratinozyten in Cokultur durch die spezifische immunzytochemische Färbung von Keratin14 und Vimentin. Für die Polymere mit variabler Elastizität wurden zusätzlich die Ablagerung extrazellulärer Matrixkomponenten und die Sekretion löslicher Faktoren durch die Zellen untersucht. Als Modellpolymere für die Variation der Elastizität wurden vernetzte Poly(n-butylacrylate) (cPnBA) verwendet, da deren Elastizität durch den Anteil des Vernetzers eingestellt werden kann. Auf dem weniger elastischen cPnBA zeigte sich in der Cokultur ein doppelt so hohes Verhältnis von Keratinozyten zu Fibroblasten wie auf dem elastischeren cPnBA, so dass ein leichter zellselektiver Effekt angenommen werden kann. Acrylnitril-basierte Copolymere wurden als Modellpolymere für die Variation der Oberflächenladung und Hydrophilie verwendet, da die Eigenschaften durch Art und molaren Anteil des Comonomers eingestellt werden können. Durch Variation des molaren Anteils der Comonomere mit positiver bzw. negativer Ladung, Methacrylsäure-2-aminoethylester-hydrochhlorid (AEMA) und N-3-Aminopropyl-methacrylamid-hydro-chlorid (APMA) bzw. Natriumsalz der 2-Methyl-2-propen-1-sulfonsäure (NaMAS), wurde der Anteil der positiven bzw. negativen Ladung im Copolymer variiert. Durch die Erhöhung des molaren Anteils des hydrophilen Comonomers N-Vinylpyrrolidon (NVP) wurde die Hydrophilie des Copolymers gesteigert. Die Erhöhung des molaren Anteils an positiv geladenem Comonomer AEMA im Copolymer führte tendenziell zu einer höheren Keratinozytendichte, wobei die Fibroblastendichte unverändert blieb. Durch die Erhöhung des molaren Anteils des positiv geladenen Comonomers APMA ergaben sich keine deutlichen Unterschiede in Dichte, Vitalität oder Selektivität der Zellen. Durch die stufenweise Erhöhung des molaren Anteils des negativ geladenen Comonomers NaMAS konnte, wie im Falle von AEMA, eine Tendenz zur verbesserten Keratinozytenadhärenz beobachtet werden. Die Steigerung der Hydrophilie der Copolymere führte sowohl für Keratinozyten als auch für Fibroblasten zu einer reduzierten Adhärenz und Vitalität. In der vorliegenden Doktorarbeit wurde ein Testverfahren etabliert, das die Untersuchung von primären humanen Keratinozyten und primären humanen Fibroblasten in Monokultur und Cokultur auf verschiedenen Polymeren ermöglicht. Die bisherigen Ergebnisse zeigen, dass sich durch die gezielte Modifizierung verschiedener Polymereigenschaften die Adhärenz und Vitalität beider Zelltypen beeinflussen lässt. Die Reduktion der Elastizität sowie die Erhöhung des molaren Anteils geladener Comonomere führten zu einer Zunahme der Keratinozytenadhärenz. Da die Fibroblasten unbeeinflusst blieben, zeigte sich für einige der untersuchten Polymere eine leichte Zellselektivität. Diese könnte durch die weitere Erhöhung der Steifigkeit oder des Anteils geladener Comonomere möglicherweise weiter gesteigert werden. / Chemical and physical properties of polymers can influence various cell types, e.g. concerning adherence and functionality. For instance, the elasticity of a polymer can influence, which pulling force a cell can generate towards a substrate. According to the cell type, its behavior can be controlled by intracellular feedback mechanisms. The surface charge and/or hydrophilicity of a polymer initially influence the adsorption of ions, proteins and other molecules. In particular, the composition, density, and conformation of the adsorbed components mediate the cell-material interactions. Since different cell types present varying cell membrane associated proteins, sugars and lipids, it is assumed that polymer properties can induce cell specific effects. Polymers, which can regulate specific cell reactions, become more and more important for biotechnological uses and applications in the regenerative medicine. The isolation and culture of primary keratinocytes is still challenging and an adequate wound healing remains a clinical task. A polymer, which enables a preferential adherence of keratinocytes and induces a reduced adherence of dermal fibroblasts, would provide enormous advantages for keratinocyte culture systems as well as for wound dressings. To investigate the specific influence of certain polymer properties on primary human keratinocytes and fibroblasts, a cell culture system for mono- and coculture of both cell types was established. The test system was designed as a screening to investigate the influence of polymers with gradations of different properties on the cells. Thereby, the viability and density of adherent and not adhered cells, as well as the impairment of the cell membranes were analyzed in mono- and cocultures, and the selective adherence of keratinocytes in the coculture was evaluated using a specific immunocytochemical staining for keratin14 and vimentin. Furthermore, the deposition of extracellular matrix components and the secretion of soluble factors were analyzed for the elastic polymers. Since the elasticity of crosslinked poly(n-butylacrylate) (cPnBA) networks can be adjusted by the amount of the crosslinker, they were used as model polymers to investigate the influence of varying elasticity to the cells. On the less elastic cPnBA, the ratio of keratinocytes to fibroblasts was increased compared to the more elastic one. From these results, a slight cell selective effect can be assumed. Acrylonitrile-based copolymers were used as model polymers for the variation of surface charge and hydrophilicity, since their properties can be modified by the type and molar ratio of comonomers. By the variation of the molar ratio of positively charged comonomers (Methacrylic acid-2-aminoethylester hydrochloride (AEMA) and N-3-aminopropyl methacrylamide hydrochloride (APMA)), or a negatively charged comonomer (2-methyl-2-propene-1-sulfonic acid sodium salt (NaMAS)), the amount of positive or negative charges was modified. The hydrophilicity was increased by the molar ratio of the hydrophilic comonomer N-vinylpyrrolidone (NVP). With an increased molar ratio of the positively charged comonomer AEMA, a tendency towards a higher density of adherent keratinocytes could be shown, whereby, the density of adherent fibroblasts remained unaffected. With increasing molar ratios of the positively charged comonomer APMA, no differences between cell densities, viability or selectivity were detectable. Comparable to AEMA, a tendency towards improved keratinocyte adhesion could be shown with an increasing molar ratio of the negatively charged comonomer NaMAS. The increase of the hydrophilicity of the copolymers led to a reduced adherence and viability of the keratinocytes, as well as of the fibroblasts. In conclusion, a test system was established, which enables the evaluation of primary human keratinocytes and fibroblasts in contact with different polymers in monoculture, as well as in coculture. Furthermore, the present thesis shows that directed modifications of polymer properties influenced the adherence and viability of both cell types. The decrease of elasticity and the increase of the molar ratio of charged comonomers led to an increased keratinocyte adherence. Since the fibroblasts remained unaffected, slight cell selectivity was shown. By further increasing the stiffness or the amount of charged comonomers, further enhancement of this effect might be possible.

Nonwoven polypropylene has been utilized broadly in various hygienic and medical textile applications because of its excellent mechanical properties, chemical resistance, and minimal expense contrast with other synthetic polymers. However, the insufficiency of surface tethering groups, including adhesion, wettability, and hydrophilicity, some applications are not convenient on nonwoven polypropylene surfaces such as dyeing, printing, attachment of antibacterial and bioactive agents. To stimulate nonwoven polypropylene surface energy, utilization of supercritical carbon dioxide technology provides a resource-efficient and environment-friendly solution compares to other commonly developed wet chemical processes and ionized gas treatment techniques. This thesis investigates the possibility of functional group endorsement from 1,2,3,4-Butanetetracarboxylic acid onto nonwoven polypropylene surface in supercritical carbon dioxide media through impregnation where supercritical carbon dioxide acts as a solvent for the monomer and swelling agent for polypropylene. Two-level three-factor full factorial with a centre point statistical model implemented where pressure ranges from 9MPa to 13MPa, temperature ranges from 60°C to 100°C, and treatment time ranges from 6 hours to 8 hours, to optimize process condition to achieve less hydrophobic surface. Ethanol used as co-solvent and concentration of 1,2,3,4-Butanetetracarboxylic acid utilized 0.4 moles/litre in this investigation. Water contact angle analysis confirms surface functionalization for each treated sample and exhibits the highest decrease in surface hydrophobicity for (11MPa, 80°C, 7hrs) process condition treated sample (contact angle, θ = 114°). Statistical analysis shows the higher significance of temperature factor (p-value 0.008) with the feasibility of selected model efficacy (R2= 0.91). FTIR-ATR analysis authenticates the existence of hydrophilic functional groups (-OH, C=O, and C-O) from 1,2,3,4-Butanetetracarboxylic acid onto nonwoven polypropylene surface. Four stages mass loss thermogram of (11MPa, 80°C, 7hrs) process condition treated sample obtained from thermogravimetric analysis (TGA) confirm impregnation of organic molecules into nonwoven polypropylene matrix. Differential scanning calorimetry (DSC) analysis shows a 7.56% decrease in crystallinity percentage of (11MPa, 80°C, 7hrs) process condition treated sample than non-treated nonwoven polypropylene. In this investigation, each process condition treated nonwoven polypropylene surfaces achieve a less hydrophobic surface due to the impregnation of hydrophilic functional groups from 1,2,3,4-Butanetetracarboxylic acid did not accomplish hydrophilic character. Analysis among carbonyl index and work of adhesion results revealed a decrease in hydrophobicity depend on the concentration of hydrophilic functional groups on polypropylene surface and at the same time rely upon the crystallinity percentage and swelling properties of nonwoven polypropylene.

This thesis deals with the preparation of titanium dioxide films by the sol-gel process. Films were deposited by material printing on soda-lime glass plates. The thickness of layers was directed by repeated printing. Thus were prepared multi-layered TiO2 coatings. The surface topology of films was investigated by optical microscopy and scanning electron microscopy. The photocatalytic activity of these coatings was studied on a model compound 2,6-dichlorineindophenol. The influence of the number of TiO2 layers and the intensity of UV irradiation on the size of 2,6-dichlorineindophenol degradation rate constant was monitored. The photo-induced hydrophilic properties of prepared coatings were studied as well.

Despite numerous advantages of using particles in a wide range of applications, they have one drawback that is their tendency to agglomerate. One way to overcome this problem is to sterically  stabilize the particles by introducing polymeric  chains covalently attached to the surface. Surface modification by covalently attaching polymer chains to the particle surface can be achieved by e.g. a ‘grafting-from’ technique under UV irradiation. In this thesis, polylactide (PLA) particles were surface modified, under UV irradiation, with the hydrophilic monomers: acrylamide (AAm), acrylic acid (AA), and maleic anhydride (MAH). The developed ‘grafting-from’ technique was shown to be nondestructive method for surface modification of PLA particles of two different geometries. The change in surface chemistry of the PLA particles was confirmed by FTIR and XPS, indicating the success of the surface grafting technique. Force interaction between two surface grafted PLA substrates was measured by colloidal probe AFM in different salt concentrations. In order to understand the repulsive force, the AFM force profiles were compared to the DLVO theory and AdG model. Long range repulsive interactions were mainly observed when hydrophilic polymers were covalently attached to the surface of PLA particles, leading to steric interaction. Attractive force dominated the interaction when neat PLA particle was approaching each other, resulting in particle aggregation, even though short range repulsion was observed at small separation distance, i.e. approximately 10 nm. Attractive interaction was also observed when neat PLA was approaching to PAA-grafted PLA substrate. This attractive interaction was much greater than force interaction between two neat PLA substrates.  The surface grafted particles can be used in biomedical application where secondary interactions are important to overcome particle agglomeration such as particle-based drug delivery. / <p>QC 20130529</p>

Title: Structural study of nanocrystalline titanium oxide films and their temperature stability Author: Lea Chlanová Department: Department of Condensed Matter Physics Supervisor: Prof. RNDr. Radomír Kužel, CSc., Department of Condensed Matter Physics Abstract: TiO2 thin films can exhibit photocatalytic activity and photoinduced su- perhydrophilicity depending on crystallinity, phase composition and mi- crostructure. These parameters were studied by X-ray diffraction (XRD) and reflectivity (XRR) for magnetron deposited films - nanocrystalline and amorphous, namely their temperature and time evolution. For nanocrystalline films, it was found that higher partial oxygen pressure during the deposition is beneficial. Small anatase crystallites were stable up to about 450 ◦ C. Depth-profiling XRD of some samples revealed that rutile phase was only present close to the substrate. For amorphous films it was found that the crystallization depends strongly on the film thickness and it is slower for very thin films. Evolution of the intensities of anatase diffraction peaks with annealing time could be described by a modified Avrami equation. XRD profile was relatively narrow from the very be- ginning of crystallization (at about 220 ◦ C), which indicated relatively larger crystallites (> 100 nm), and hence, nanocrystalline films...

Práce popisuje přípravu tenkých transparentních vrstev oxidu titaničitého metodou sol-gel procesu s reverzními micelami, které jsou jedinečným uskupením zajišťujícím uniformní velikost připravených částic. Neionogenní tenzid byl použit jako templát. Pomocí materiálového tisku, tedy specializovanou formou inkoustového tisku, byly připraveny tenké filmy oxidu titaničitého nanesením 1–4 vrstev. Po kalcinaci byly připravené vrstvy oxidu titaničitého charakterizované šířkou zakázaného pásu. Struktura vrstev byla popsána optickou mikroskopií a SEM. Fotokatalytická aktivita byla ověřena oxidační reakcí 2,6-dichlorindofenolu a rozkladem kyseliny stearové, která byla přímo natištěna na vrstvy oxidu titaničitého. Fotoindukovaná změna hydrofility byla studována pomocí měření kontaktního úhlu smáčení vody. Fotokatalytická účinnost připravených filmů rostla s počtem vrstev oxidu titaničitého.

This thesis reports on the synthesis and characterisation of various types of oxidised multiwalled carbon nanotubes (O-MWCNTs) modified polymeric membranes. These OMWCNT modified polymeric membranes were then assessed in terms of their remediation potential, in particular for the removal of estrogenic hormones, dissolved proteins and salts from brackish water sources. The fabricated O-MWCNT-based polyethersulfone (PES) membranes were applied as (i) adsorptive membranes, (ii) molecular-sieving membranes and (iii) as membrane substrates for thin-film composite nanofiltration (NF) membrane preparation. The research work commences with the preparation of MWCNTs via a facile catalytic chemical vapour deposition method and their chemical oxidation with strong acids in order to introduce hydrophilic carboxylic (–COOH) and hydroxyl (–OH) surface functional group moieties on the MWCNT outer walls. Intrinsically, MWCNTs are chemically inert and tend to form agglomerated nanoclusters (due to van der Waals interaction forces), which induce further difficulties in their homogenous dispersion in polar solvents (such as N-methyl-2- pyrrolidone and dimethylacetamide) employed to dissolve the polymers in the study. The introduction of these oxygen-containing moieties was therefore necessary to aid the dispersion of MWCNTs in organic solvents and for their enhanced interaction with PES and sulfonated polysulfone (SPSf). The PES/O-MWCNT ultrafiltration (UF) membranes were produced via a non-solvent induced phase separation (NIPS) method and employed in the adsorptive removal of natural hormone estrone (E1). The PES/O-MWCNT UF membranes thus prepared were characterised using SEM, AFM, zeta potential measurements and MWCO experiments. It was found that the adsorption of E1 initially increased with an increase in O-MWCNT content followed by a constant decline on further increments. Moreover, the inclusion of OMWCNTs (0.5 wt.%) in the PES membrane matrix resulted in an increase in the maximum adsorption capacity for E1 compared to pristine PES membrane, i.e., 31.25 mg/g adsorption capacity was achieved for PES/O-MWCNT compared to 23.81 mg/g for bare PES UF membrane. Based on the correlation coefficients, the Freundlich isotherm provided a better fit for the adsorption data and the adsorption kinetics followed the pseudo-second order kinetic model. Interestingly, after five regeneration cycles, the PES/O-MWCNT membranes were found to maintain similar adsorption efficiencies. The PES/O-MWCNT membranes thus prepared, present a viable approach for the removal of natural hormones and other endocrine disruptors present in water systems compared to the use of common adsorbents such as activated carbon, which end up generating large amounts of chemical sludge that require disposal in the environment. The third part of the study focused on the controlled formation of macrovoid-free polyethersulfone/sulfonated polysulfone (PES/SPSf) UF membranes with high water permeabilities, mechanical strength and antifouling properties, in the presence of O-MWCNTs. To date, the majority of polymeric nanocomposite membranes modified with O-MWCNTs as nanofillers, generally have finger-like structures and macrovoids in the membrane sublayer. While the presence of finger-like structures is favoured for the reduction in mass flow resistance, their presence induces mechanically weak points in the membrane and reduces the nanocomposite membranes’ mechanical strength properties and long-term performance stability. As such macrovoid-free PES/SPSf/O-MWCNT membranes were fabricated via the NIPS techniques, using H2O and polyethylene glycol (PEG 20 kDa) as non-solvent additives. The SEM cross-sectional images showed that a fully sponge-like morphology of the PES/SPSf membrane can be achieved in the presence of different loadings of O-MWCNTs. This was attributable to the formation of stronger hydrogen bonds between the SPSf polymer and non-solvent additives i.e., H2O, PEG 20kDa and OMWCNTs. The combination of the macrovoid-free morphology and homogenous distribution of high mechanical strength O-MWCNTs in the membrane matrix provided excellent mechanical strength enhancements for PES/SPSf/O-MWCNT membranes. Additionally, pure water flux initially increased from 598 L/m2 .h to 713 L/m2 .h followed by a decline to 578 L/m2 .h upon further increments in O-MWCNT contents, due to agglomeration of O-MWCNTs at higher loadings. The fabricated PES/SPSf/O-MWCNT membranes also displayed superior antifouling properties (FRR > 90%) and antibacterial properties (99% bacterial killing ratio) against E. coli bacteria. The fabricated support fabricfree PES/SPSf/O-MWCNT UF membranes with macrovoid-free sublayer morphologies displayed attractive features for use as UF membranes in the pre-treatment stages of water treatment and as support substrates for the preparation of TFC membranes. In general, sponge-like and macrovoid-free membrane structures are regarded as unfit for use as support membranes for TFC membrane preparation since they increase the membrane’s resistance to water flow, thereby reducing the overall TFC membrane permeability. This assumption has largely been based on sponge-like and macrovoid-free membranes structures achieved through the use of extremely high polymer concentrations, particularly using polysulfone (PSf) polymer. Hence, the sponge-like structures formed are very dense and less porous. Nevertheless, the macrovoid-free PES/SPSf/O-MWCNT membranes produced in this study, consisted of open cellular network microstructures within the membrane sublayer, which could be visualised at higher SEM magnifications. This part of the work therefore investigated the role of hydrophilic, macrovoid-free PES/SPSf and PES/SPSf/O-MWCNT as support membranes on the performance of TFC NF membranes. The TFC NF membranes were prepared via an efficient interfacial polymerization reaction between piperazine (PIP) and trimesoyl chloride (TMC). The deposition of the polyamide thin-film layer was confirmed by ATR-FTIR, SEM, AFM, contact angle and zeta potential measurements. Membrane performance results showed that TFC NF membranes fabricated on PES/SPSf/O-MWCNT support membranes displayed a 35% improvement in pure water flux with comparable salt rejections from those prepared on bare PES/SPSf support membranes. Salt rejection followed the order of Na2SO4 > MgSO4 > NaCl, which is typical for negatively charged NF membranes. It was established that the presence of hydrophilic O-MWCNTs in the support membrane allowed for the formation of a thin polyamide layer on the top surface of the support membrane, which gave rise to enhanced water permeability of the TFC NF membrane and the possibility of polyamide rejection layer within the support membrane pore channels. To further improve the performance of the TFC NF membranes, in particular, the monovalent/bivalent salt selectivity, a mixture of PIP and 2,4-diaminobenzene sulfonic acid (2,4-DABSA) at different weight ratios was prepared in the aqueous solution and reacted with TMC in the organic phase solution. It was found that the addition of low monomer weight ratio of 2,4-DABSA in the amine mixture, lead to the generation of a sulfonated TFC NF membrane with superior membrane performance in terms of pure water permeability (30.2 L/m2 .h), monovalent/bivalent salt selectivity (𝛼NaCl/Na2SO4 = 25.0) at low operating pressures (3 bar) and salt concentrations in the range of brackish waters. This was attributable to the combined presence of sulfonic acid groups on the membrane surface and the formation of the thin polyamide layer. Moreover, sulfonated TFC NF membranes exhibited good antifouling properties against bovine serum albumin (BSA), with FRR of 96.4% after three cycles of fouling and cleaning, with a fairly stable membrane performance over a 10-day period of pure water flux and Na2SO4 rejection testing. Indeed, the use of a macrovoid-free PES/SPSf/O-MWCNT support membrane did not only provide the mechanical strength for the deposition of TFC NF membrane, but also their open, cellular network microstructure, combined with high hydrophilicity and large surface pore sizes were beneficial in the reduction of polyamide layer thickness, and subsequently in the enhancement of TFC NF membrane performance. The study provided insightful information on lesser known aspects of O-MWCNT incorporated polymeric membranes, with regards to membrane structural configurations in relation to the membrane structure-performance relationships. It has been deduced that (i) the right combination of membrane surface characteristics and adsorbate solution chemistry is necessary for an open UF membrane to display reasonable removal efficiencies for low molecular-weight solutes, (ii) the combination of macrovoid-free membrane morphology with good dispersion of O-MWCNTs in the polymer matrix is necessary to realise significant enhancements in the mechanical properties of sulfonated membrane and (iii) formation of a thin sulfonated polyamide layer on top of the hydrophilic PES/SPSf/O-MWCNT support membrane is necessary to achieve high salt selectivity, and allow for the sulfonated TFC NF membrane to be operated at low pressures. / College of Engineering, Science and Technology

No description available.

Les maladies ostéoarticulaires représentent environ 10% de l’ensemble des pathologies identifiées en France chaque année. Ces maladies inflammatoires et dégénératives des articulations sont pour la plupart consécutives au vieillissement ou à un traumatisme et évoluent vers l’usure des cartilages, d’où un handicap sévère. Comme aucun traitement ne permet la réparation totale du tissu cartilagineux, la recherche médicale développe des techniques d’ingénierie tissulaire. Ces techniques utilisent des substrats polymériques et des cellules souches qui sont « contraints » de se développer pour former du tissu cartilagineux. Cependant, ces techniques ne peuvent pas encore être utilisées à l’échelle d’une articulation complète car il n’est pas possible de reproduire ex vivo à grande échelle la structure et les propriétés mécaniques et physicochimiques du cartilage articulaire. Dans ce contexte, les travaux de cette thèse ont permis de développer des matériaux polymères capables d’être implantés à l’échelle macroscopique dans les articulations pathologiques afin de combler l’usure des cartilages. Pour se faire, de nouveaux biomatériaux - hydrogels p(HEMA) - ont été obtenus en contrôlant le caractère hydrophile des hydrogels p(HEMA) au cours de leur synthèse chimique en présence de différents co-monomères (acide acrylique, acrylamide, acrylate d'éthylène et acrylate de butyle). Partant de là, les propriétés physicochimiques, mécaniques et tribologiques de ces nouveaux hydrogels ont été optimisées afin d’obtenir des propriétés similaires à celles du cartilage articulaire sain. Ensuite, la libération contrôlée de médicaments par ces hydrogels a été étudiée afin de minimiser les risques inflammatoires lors de leur utilisation en ingénierie tissulaire du cartilage articulaire. / Osteoarticular diseases re present approximately 10% of all diseases identified in France each year. These inflammatory and degenerative joint disease are mostly consecutive with age or injuries and the wear progress of cartilage, resulting in severe disability. Because no treatment will total repair the cartilage tissue, medical research is developing techniques based on tissue engineering. These techniques use polymer substrates and stem cells that are "forced" to develop into cartilage tissue. However, these techniques cannot be used across a run articulation because Il is not possible-to replicate ex vivo a large-scale structure and the physicochemical and mechanical properties of articular cartilage. In this context, the purpose of this thesis is to develop polymer materials that can be implanted at the macroscopic level in the joints disease that will fill the wear of the cartilage. To do so, new biomaterials - hydrogels p (HEMA)- were obtained by controlling the hydrophilic nature of hydrogels p (HEMA) during their chemical synthesis in the presence of various co-monomers (acrylic acid, acrylamide, acrylate ethylene and butyl acrylate). From there, physicochemical, mechanical and tribological properties of these novel hydrogels have been optimized to obtain similar properties to those of healthy articular cartilage. Then, the controlled release of drugs from these hydrogels was studied to minimize inflammatory when used in tissue engineering of articular cartilage.