Surface-enhanced Raman scattering (SERS) microscopy is a novel method of optical imaging for the localization and quantification of target molecules in cells and tissue specimens. The major advantages of SERS over fluorescence are quantification and spectral multiplexing due to the small line width of vibrational Raman bands. The position of the plasmon band of both hollow gold/silver nanoshells and silica-encapsulated gold nanoclusters can be tuned for maximum SERS enhancement upon red laser excitation, which is optimal for minimizing the disturbing autofluorescence of tissue. In this work, silica-encapsulated and non-encapsulated SERS particles were used for the localization of target proteins in prostate tissue specimens. Two different biofunctionalization methods were established for each type of SERS particles. The cross-linking method based on s-NHS/EDC chemistry was modified for covalently conjugating proteins to hollow gold/silver nanoshells and gold nanostars in order to minimize the aggregation of SERS nanoparticles during and after cross-linking. As an alternative to covalent conjugation chemistry, the noncovalent binding of antibodies to the SERS particles via an adapter protein (protein A/G) was established. The influence of several factors that determine the quality of results obtained by SERS imaging, such as the number of immuno-SERS conjugates, incubation time, antigen retrieval and blocking buffer, were investigated. Rapid SERS microscopy with 30 msec acquisition time per pixel was enabled by using silica-encapsulated gold nanoclusters for the localization of p63 proteins on prostate tissue specimens from healthy donors. Two-color SERS experiments for the parallel localization of PSA and p63 were performed with silica-encapsulated and non-encapsulated nanoshells. The quality of the results depends less on the nature of the surface chemistry of the nanoparticles (with or without silica encapsulation), but more on the blocking buffer and the antigen retrieval method. Silica-encapsulated gold nanoclusters were also used for the simultaneous quantification of three cytokines (IL1, IL8 and TNF- α) in a SERS-based sandwich immunoassay with a detection limit of ca. 0.3 pM. Keywords: Raman, SERS microscopy, biocompatibility of nanoparticles, cross-linking, antigen unmasking methods, antigen detection, immunohistochemistry, immunoassay.

Ce travail porte sur la modification de matrices polymères à base de fluorure de vinylidene pour permettre leur utilisation en tant que membrane séparatrice dans les supercapacités. Basé sur un procédé d‘irradiation par rayonnement γ, l‘objectif principal était la limitation du gonflement du polymère lorsqu‘il est mis en contact d‘un milieu liquide relatif à l‘application tout en gardant d‘excellentes affinités avec celui-ci. Le processus de base exploité étant la formation et la réaction des radicaux lors de l‘irradiation du polymère, une partie de la thèse a été consacrée à leur étude par résonance paramagnétique électronique (RPE). Un modèle de simulation de spectre RPE a été mis en place pour identifier et quantifier chacune des espèces radicalaires. L‘effet de la dose d‘irradiation, de la durée d‘un recuit et de la nature de la matrice polymère (homo, copolymère) sur la proportion de ces espèces et sur leur réactivité a été évalué. Un lien avec la formation d‘un réseau a été proposé. Une attention particulière a ensuite été apportée à l‘augmentation de la densité de réticulation avec le concours d‘un agent réticulant, le TAIC. Pour terminer, une stratégie de modification des propriétés de surface du PVDF a été élaborée. Elle consiste dans un premier temps à radiogreffer un polymère à la surface du PVDF puis à modifier, dans un second temps, les greffons par une chimie douce et sélective. En conclusion, les approches complémentaires développées au cours de cette thèse ont permis de comprendre la radiolyse des polymères et de mettre à profit les processus élémentaires pour développer des stratégies robustes et prometteuses de modulation des propriétés. / This work deals with the modification of VDF-based polymer induced by γ-radiation as the polymer may be used in electrochemical supercapacitors. The main objective was to limit the swelling of the fluorinated matrix with a given electrolyte while a good wetting of the polymer by the liquid was also required. As the main basic process involved in polymer radiolysis is the formation of radicals, a part of the work was dedicated to the study of such species by using Electron Spin Resonance spectroscopy. A simulation model of ESR spectra was established in order to identify and quantify each radical species. The effect of several parameters such as radiation dose, annealing time or the nature of polymer matrix on the concentration of each species where investigated. A relation with the evolution of the crosslink density of the network formed during the radiolisys was proposed. In addition, one of the key steps of this work was to study the radiation crosslinking ability of VDF-based polymers and find a way to increase the crosslink density. This was achieved by incorporating, prior to the radiation process, a radiation sensitive crosslinker: TAIC. Finally, a new strategy based on the modification of surface properties of PVDF was investigated. It consists in the radiation grafting of pentafluorstyrene onto PVDF surface followed by the chemioselective functionalization of the grafted segments. As a conclusion, the different approaches used in this thesis allowed us to understand the radiolysis of VDF-based polymers and take advantage of the elementary process involved in this type of chemistry, to build up robust and promising strategies for tuning properties.

The cell wall provides a complex and rigid structure to the plant for support, protection from environmental factors, and transport. It is mainly composed of polysaccharides, proteins, and lignin. Arabinoxylan (AX), pectin (P), and cellulose (C) are the main components of cereal cell walls and are particularly concentrated in the bran portion of the grain. Cereal arabinoxylans create networks in plant cell walls in which other cell wall polysaccharides are imbedded forming complex matrices. These networks give an insolubility profile to plant cell wall. A previous study in our lab showed that soluble crosslinked arabinoxylan with relatively high residual ferulic acid from corn bran provided advantageous <i>in vitro </i>human fecal fermentation products and promoted butyrogenic gut bacteria. In the present work, arabinoxylan was isolated from corn bran with a mild sodium hydroxide concentration to keep most of its ferulic acid content. Highly ferulated corn bran arabinoxylan was crosslinked to create an insoluble network to mimic the cereal grain cell wall matrices. Firstly, arabinoxylan film (Cax-F), pectin film (P-F), the film produced by embedding pectin into arabinoxylan networks (CaxP-F), and cellulose embedding arabinoxylan matrices (CaxC-F), and embedding the mixture of cellulose and pectin into arabinoxylan networks (CaxCP-F) were fabricated into simulated plant cell wall materials. Water solubility of films in terms of monosaccharide content was examined and revealed that Cax-F was insoluble, and P-F was partially insoluble, and nanosized pectin and cellulose were partially entrapped inside the crosslinked-arabinoxylan matrices. In a further study, these films were used in an <i>in vitro </i>human fecal fermentation assay to understand how gut microbiota access and utilize the different simulated plant cell walls to highlight the role of each plant cell wall component during colonic fermentation. <i>In vitro </i>fecal samples, obtained from three healthy donors were used to ferment the films (Cax-F, P-F, CaxP-F, CaxC-F, and CaxCP-F) and controls (free form of cell wall components -Cax, P and C). The fabricated films that were compositionally similar to cell walls were fermented more slowly than the free polysaccharides (Cax and P). Besides, CaxP-F produced the highest short chain fatty acids (SCFA) amount among the films after 24 hour <i>in vitro </i>fecal fermentation. Regarding specific SCFA, butyrate molar ratio of all films was significantly higher than the free, soluble Cax and P. 16S rRNA gene sequencing explained the differences of the butyrate proportion derived from specific butyrogenic bacteria. Particularly, some bacteria, especially in a butyrogenic genera from Clostridium cluster XIVa, were increased in arabinoxylan films forms compared to the native free arabinoxylan polysaccharide. However, no changes were observed between P and P-F in terms of both end products (SCFA) and microbiota compositions. Moreover, CaxP-F promoted the butyrogenic bacteria in fecal samples compared with pectin alone, arabinoxylan alone, and the arabinoxylan film. Differences in matrix insolubility of the film, which was high for the covalently linked arabinoxylan films, but low for the non-covalent ionic-linked pectin film, appears to play an important role in targeting Clostridial bacterial groups. Overall, the cell wall-like films were useful to understand which bacteria degrade them related to their physical form and location of the fiber polymers. This study showed how fabricated model plant cell wall films influence specificity and competitiveness of some gut bacteria and suggest that fabricated materials using natural fibers might be used for targeted support of certain gut bacteria and bacterial groups.

Bei der Herstellung und Lagerung von Milch und Milchprodukten kommt es in unterschiedlichem Ausmaß zur Bildung von reversiblen und irreversiblen Proteinquervernetzungen. Dabei verändern sich neben technologischen auch ernährungsphysiologische Eigenschaften des Produktes. Die für die Oligomerisation verantwortlichen Strukturen sind bisher nur zum Teil bekannt. Daher soll in dieser Arbeit zunächst das Ausmaß der Quervernetzung in einer größeren Anzahl an handelsüblichen Milchprodukten ermittelt und mit den für diese Proben gemessenen Gehalten der für irreversible Quervernetzungsreaktionen in Lebensmitteln wichtigen Aminosäurederivate Lysinoalanin (LAL) und Histidinoalanin (HAL) verglichen werden. Der Beitrag dieser beiden Dehydroalanin-Derivate für Oligomerisationen ist jedoch stark von der Art ihres Bildungsweges abhängig. Da es in der Literatur keine abschließenden Untersuchungen über eine intra- oder intermolekularen Bildung von LAL und HAL gibt, ist dies eine grundlegende Aufgabe, um in der Folge den Anteil von unbekannten Crosslinks für die analysierten Lebensmittel bestimmen zu können. Die Identifizierung dieser vorhandenen, jedoch strukturell unbekannten Crosslinks ist ein weiteres Ziel der vorliegenden Untersuchungen. Hierbei richtet sich das Interesse vor allem auf Quervernetzungsprodukte, die im Zusammenhang mit der nicht-enzymatischen Bräunung oder Maillard-Reaktion gebildet werden. Aus der Literatur ist eine Vielzahl von Verbindungen, die an der Oligomerisation und den damit verbundenen Eigenschaftsänderungen von Proteinen beteiligt sind, aus Modellansätzen oder in vivo-Studien bekannt. Untersuchungen zum Vorkommen dieser Strukturen in handelsüblichen Lebensmitteln fehlen jedoch in den überwiegenden Fällen. Dazu ist neben der Synthese einzelner Verbindungen als Standardmaterial die Entwicklung bzw. Optimierung der Analytik für Lebensmittelmatrices durchzuführen. Einige der bekannten, aber noch nicht in Lebensmitteln nachgewiesenen Crosslinkaminosäuren zeichnen sich durch eine charakteristische Fluoreszenz aus. Die Zunahme der Fluoreszenz in technologisch hergestellten Milchprodukten ist aus der Literatur bekannt, eine Identifizierung der dafür verantwortlichen Verbindungen fehlt hingegen. Daher ist ein weiteres Ziel dieser Arbeit, individuelle, fluoreszierende Crosslinks in Milchprodukten zu charakterisieren und zu quantifizieren.

Les recherches réalisées au cours de ce doctorat portent sur l’étude et l’optimisation de mélanges de polymères, utilisés en tant qu’électrolytes solides polymères (SPEs) dans les batteries lithium et lithium-ion. Les composants de la batterie doivent pouvoir être mis en forme par un procédé sans solvant (extrusion), afin de réduire les impacts du solvant sur les propriétés de la batterie et d’optimiser la production (diminution de la toxicité et du temps de production). Pour répondre à ces objectifs, une étude a d’abord été menée sur des mélanges de polymères, sélectionnés d’après leurs propriétés individuelles, en se concentrant notamment sur les interactions entre le sel de lithium et chaque polymère. Un classement des interactions a été développé et a permis de montrer que le principal facteur les favorisant est le nombre donneur des groupements fonctionnels polaires présents sur les chaînes polymères. Enfin, les effets de ces interactions sur les phénomènes de transport ionique dans les mélanges ont été investigués. Par la suite, l’étude s’est focalisée sur les couples de polymères ayant des propriétés prometteuses et complémentaires, tels que le poly(oxyde d’éthylène) (POE) ou le polycaprolactone (PCL), qui ont des conductivités ioniques élevées, et un copolymère butadiène-acrylonitrile hydrogéné (HNBR), qui possède des propriétés mécaniques intéressantes mais une conductivité ionique limitée. Il a été conclu que ces mélanges présentent des propriétés encourageantes, comparées aux SPEs composés d’un unique polymère, telles que des conductivités ioniques élevées sur une large plage de températures, ainsi que de meilleures propriétés de stabilités mécanique et thermique. La dernière partie de ces travaux s’est portée sur l’optimisation des propriétés de ces mélanges, par une méthode innovante de réticulation sélective d’une des phases. Pour conclure ce doctorat, l’objectif final a été de réaliser un prototype performant de batterie lithium tout solide, entièrement obtenu par extrusion, et dont l’électrolyte et le liant au sein des électrodes composites sont composés des électrolytes polymères optimisés. Les résultats prometteurs obtenus ont permis la soumission d’un brevet, en association avec le partenaire industriel (TotalEnergies). / The research carried out during this PhD is focused on the study and optimization of polymer blends, used as solid polymer electrolytes (SPEs) in lithium and lithium-ion batteries. All components of the battery must be shaped by a solvent-free process (extrusion), in order to limit impacts of the solvent on the battery properties and improve the production process (reduce toxicity and production time). To achieve these objectives, a study was first conducted on a set of polymer blends, selected on the basis of their individual properties, with particular emphasis on the interactions between the lithium salt and each polymer. A ranking of the lithium salt solvating ability of these polymers was developed and revealed that the main factor affecting these interactions is the donor number of polar functional groups on the polymer backbones. The effects of these interactions on the ionic transport phenomena in blend electrolytes have been examined. Subsequent work focused on polymer couples with the most promising and complementary properties, such as poly(ethylene oxide) (PEO) or polycaprolactone (PCL), which exhibit high ionic conductivities, and a hydrogenated nitrile butadiene rubber (HNBR) with interesting mechanical properties but a lower ionic conductivity. It was concluded that these blends show encouraging properties, compared to single-polymer SPEs, such as higher ionic conductivities over a wide temperature range, as well as improved mechanical and thermal stability properties. The final research project was the optimization of these blend electrolytes using an innovative method of selective cross-linking of one of the polymer phases. The main aim of this thesis was to develop an efficient prototype of an all-solid-state lithium battery, entirely obtained by extrusion, in which both the electrolyte and the binder of the composite electrodes are composed of optimized polymer electrolytes. The promising results obtained have led to the filing of a patent, in association with the industrial partner (TotalEnergies).

Organische Leuchtdioden weisen, verglichen mit anorganischen Leuchtdioden, viele Vorteile auf. So sind sie nicht nur energiesparender, sondern können auch in neuen flexiblen Technologien verwendet werden. Um ihr volles Potenzial auszuschöpfen, können zusätzliche Schichten und neue Materialien hinzugefügt werden. Der Ersatz spröder Elektroden durch dünne Metallschichten kann OLEDs flexibler machen, Zwischenschichten verbessern den Ladungstransport und neuartige Materialien können die Lösungsprozessierung von OLEDs vereinfachen. In den Kapiteln dieser Arbeit wurden je ein Ansatz zur Steigerung der Leistung von OLEDs untersucht. Es wurden dünne Silberschichten aus einer partikelfreien Silbertinte mittels Tintenstrahldruck hergestellt und ihre optischen sowie elektrischen charakterisiert. Die gedruckten Elektroden zeigen eine hohe Biegefestigkeit, bei gleichbleibend guten elektrischen Eigenschaften. Die damit hergestellten Leuchtdioden übertreffen in ihrer Effizienz Referenzdioden mit Indium Zinn Oxid Elektroden. Um die Effizienz organischer Leuchtdioden weiter steigern zu können wurden anschließend Zwischenschichten untersucht. Mittels einer gemischten Schicht aus Zinkoxid und einem Polymer konnte die Effizienz von invertierten Leuchtdioden signifikant gesteigert werden. Weiterhin wurden zwei neu synthetisierte Moleküle dazu verwendet, um die Benetzung von Perowskiten auf Elektroden zu verbessern und somit ihre Herstellbarkeit mittels Tintenstrahldruck zu ermöglichen. Abschließend wurde das Quervernetzen von Polymeren zur Herstellung von Mehrschichtsystemen erforscht. Hierbei wird ein die Löslichkeit eines Polymers durch verschiedene Ansätze verringert. Anhand des lichtemittierenden Polymers Super Yellow wurde dies demonstriert. Die Beständigkeit einer Schicht aus Super Yellow gegenüber Toluol konnte erfolgreich stark erhöht werden. Somit wurde eine nachfolgende Prozessierung einer zusätzlichen Schicht aus demselben Lösungsmittel ermöglicht. / Organic light-emitting diodes have many advantages compared to their inorganic counterparts. Not only can they be used more energy-efficiently, but they can also be used in new, flexible technologies. To reach their full potential, additional layers and new materials can be added. Replacing brittle electrodes with thin metal layers can make OLEDs more flexible, intermediate layers improve charge transport, and novel materials can simplify solution processing of OLEDs. In each of the chapters of this thesis, an approach to increasing the performance of OLEDs was examined. Thin silver layers were produced from a particle-free silver ink using inkjet. Their optical and electrical properties were characterized. The printed electrodes show a high flexural strength while retaining good electrical properties. The efficacy of the light-emitting diodes produced in this way exceeds that of reference diodes. To be able to further increase the efficiency of organic light-emitting diodes, intermediate layers made of new material combinations were subsequently investigated. The efficiency of inverted light-emitting diodes could be significantly increased by means of a blend intermediate layer made of zinc oxide and a polymer. Furthermore, two newly synthesized molecules were used to improve the wetting of perovskites on electrodes and thus enable their manufacturability using inkjet printing. Finally, crosslinking of polymers to fabricate multilayer devices was investigated. Here, the solubility of a polymer is reduced by various approaches. This principle was demonstrated using the light-emitting polymer Super Yellow. The resistance of a layer of Super Yellow against toluene was successfully reduced significantly. Thus, subsequent processing of an additional layer from the same solvent was made possible.

Three-dimensional printing technologies exhibit tremendous potential in the advancing fields of tissue engineering and regenerative medicine due to the precise spatial control over depositing the biomaterial. Despite their widespread utilization and numerous advantages, the development of suitable novel biomaterials for extrusion-based 3D printing of scaffolds that support cell attachment, proliferation, and vascularization remains a challenge. Multi-material composite hydrogels present incredible potential in this field. Thus, in this work, a multi-material composite hydrogel with a promising formulation of chitosan/gelatin functionalized with egg white was developed, which provides good printability and shape fidelity. In addition, a series of comparative analyses of different crosslinking agents and processes based on tripolyphosphate (TPP), genipin (GP), and glutaraldehyde (GTA) were investigated and compared to select the ideal crosslinking strategy to enhance the physicochemical and biological properties of the fabricated scaffolds. All of the results indicate that the composite hydrogel and the resulting scaffolds utilizing TPP crosslinking have great potential in tissue engineering, especially for supporting neo-vessel growth into the scaffold and promoting angiogenesis within engineered tissues.

This thesis focuses on the synthesis and characterization of various poly(arylene ether)s to improve the efficiency of gas separation and water desalination membranes. This class of polymers includes polymers such as poly(arylene ether sulfone), poly(arylene ether ketone) and poly(phenylene oxide) which offer excellent thermal and mechanical stability and usually have high enough rigidity to support gas separation and water desalination operations. Besides the plethora of properties offered by the homopolymers, these polymers can also be post-modified to cater to specific needs. For example, the polyphenylene oxides have been brominated to increase the permeability for gas separation applications. Blending is another viable method to impart desirable properties to polymers. Bisphenol A based poly(arylene ether ketone) (BPAPAEK) has been blended with commercially available poly(2,6-dimethylphenylene oxide)s (PPO) of different molecular weights in a fixed ratio (66/34 wt/wt) and in various ratios of a 22000 g/mol PPO. All the blends were UV crosslinked to minimize plasticization by condensable gases and analyzed for gel fractions, whereas, only the 22,000 g/mol blends were tested for transport properties since they yielded the highest gel fractions and exhibited the best mechanical properties. The crosslinking reduced the free volume and improved the selectivity with some drop in permeability. The blends with 90% of the 22000 g/mol PPO by weight was plotted closest to the upperbound. A phosphine oxide based poly(arylene ether ketone) (POPAEK) was blended with the various PPOs in a similar manner. The results were compared to the BPAPAEK based blends in terms of miscibility behavior and transport properties. It was found that the POPAEK based blends had higher permeability due to the higher fractional free volumes of the POPAEK. The POPAEK was more compatible with the PPOs than BPAPAEK as seen by analyzing various blend permeability models, mechanical properties and scanning electron microscope images. Moreover, blends with both the PAEKs displayed only a small drop in mechanical properties, such as the Young's modulus and the yield strength in comparison to the parent polymers. Hydroquinone based poly(arylene ether sulfone) oligomers were synthesized, post-sulfonated and chemically crosslinked to determine the effect of water uptake, fixed charge concentration and block length of oligomers on the salt permeability and the hydrated mechanical properties of the networks. The sulfonic acid groups were placed strategically and quantitatively on the hydroquinone units. The strategic placement of the acid groups may help in maintaining high rejection of monovalent ions in the presence of divalent ions, as shown in unpublished work by our group. It was found that the water uptake and fixed charge density had the opposite effects on the salt permeability. Also, the salt permeability varied differently for 5000g/mol and 10000g/mol block based networks. Another polymer that was investigated in this thesis was poly(2-ethyl-2-oxazoline) (PEtOx). An elaborate account of synthesis of monofunctional, heterobifunctional and telechelic poly(2-ethyl-2-oxazoline)s using different initiators including methyl triflate, activated alkyl halides (e.g., benzyl halides), and non-activated alkyl halides has been presented in this thesis. Endgroup functionalities and molecular weight distributions were studied by SEC, 1H NMR and titrations. The oligomers initiated with the benzyl or xylyl chloride had a PDI of 1.3-1.4 which is broader than expected for a living cationic ring opened polymer. This was attributed to the participation of covalent species which propagated slowly in the activated halide reactions. These oligomers were quantitatively terminated as proven by NMR and titrations. Due to the molecular weight distributions and quantitative termination these oligomers were deemed to be desirable for drug delivery applications. / PHD / This work pivots around the synthesis and characterization of different classes of polymers which are long molecules made by joining small molecules. The structure-property relationships of different polymers with respect to applications such as gas separation, water desalination and drug delivery were examined. The first two projects were focused of gas separation applications. Gas separation is an essential process used to recover the required gas from a mixture of gases. This process is used in a number of industries such as natural gas, hydrogen recovery and air dehumidification. In these projects, gas separation membranes were used to remove non combustible components of natural gas such as carbon dioxide and hydrogen sulfide. Two different types of poly(arylene ether ketone)s (PAEKs) (a kind of polymer) were blended with a commercial polymer called poly(phenylene oxide) (PPO) and crosslinked at the surfaces to improve the gas transport properties of the commercial polymer. PPOs have high gas permeability and a low selectivity. In other words even though the PPO membranes would alow the gasses to pass through easily, the efficiency of gas separation would be low. The blending with the PAEKs improved the selectivity of the PPOs without much loss in throughput. These blends of the two different PAEKs were compared for transport and other relavent properties. It was found that the transport properties of the commercial polymer were improved markedly without much loss in mechanical properties which are usually sacrificed upon blending of two uncomaptible polymers. Water desalination applications were looked into for a polymer class called polysulfones. About 40% of the world’s population lives in water stressed areas. In order to address the water crisis, there is a need to look beyond primitive methods such as distillation which are inefficient. Hence, the polymeric membrane separations which do not involve phase change (eg liquid to gas and then back to liquid in distillation) were examined. The currently used polyamide membranes have a rough surface because of the way they are made, making them prone to deposition of salt and organic matter. This deposition makes them inefficient. They are also prone to degradation by chlorine. The polysulfones membranes have a smoother surface less prone to these depositions. Their resistance to chlorine makes them more viable for water desalination applications. The polysulfones were post modified to introduce charges to make them more suitable for water desalination purposes. The charges repelled the ions of same polarity and made the polymer more hydrophilic. However, as the number of charges increased, the water uptake of the polymer increased which resulted in a decrease in the effectiveness of salt /ion rejection. To increase the charge density of the polymers by (the effectiveness of ion rejection), the polymer chains were crosslinked at the ends. For deleniating the structure property relationships, the amount of charges were varied and two sets of chain lengths were studied. The salt permeability decreased with increase in fixed charge concentration and decrease in water uptake. Poly(2-Oxazolines), were investigated as potential drug delivery vehicles. Polymeric drug delivery vehicles have been used to control the rate of release of drugs in the body to avoid side effects. Another advantage of polymeric drug delivery systems is making the water insoluble drugs more compatible with the fluids in the body. Currently, polyethylene oxides are being used as drug delivery vehicles. However, these polymers have been known to produce antibodies in some people. In this work, poly(2-oxazolines) which are known to be more compatible with human body than PEOs were prepared using different initiators and end cappers to prepare an elaborate repertoire of controlled molecular weight and controlled functionality oligomers for further modification.

Diese Arbeit liefert Informationen über die neuartige Synthese von physikalischen durch Glycin vernetzten Cellulosehydrogelen. Ihre Herstellung, Morphologie, Wasseraufnahmevermögen, mechanische und thermische Eigenschaften, Wiederverwendbarkeit und Stabilität werden detailliert beschrieben. Die Arbeit präsentiert eine umfassende Studie über die Herstellung, Charakterisierung, Morphologie und thermischen Eigenschaften von Hydrogelen und validiert die Verwendung von Cellulose-Glycin-Hydrogelen für Anwendungen mit abgeschiedenen Goldnanopartikeln. / This thesis provides information about the novel synthesis of cellulose hydrogels physically crosslinked by glycine; their fabrication, morphology, water absorption capacity, mechanical properties, thermal properties, reusability, stability and gold nanoparticle deposition. The work validates also the use of cellulose–glycine hydrogels for gold nanoparticle deposition applications and presents a comprehensive study of gold nanoparticle deposited hydrogels about their fabrication, characterization, morphology and thermal properties.

Ziel der vorliegenden Arbeit war die Durchführung sowie die Untersuchung ausgewählter Verfahrenswege zur chemischen und thermischen Vernetzung von Polysacchariden und Proteinen aus nachwachsenden Rohstoffen. Darüber hinaus wurden Hypothesen zu den Anwendungsmöglichkeiten der untersuchten vernetzten Polymere erstellt. Hierfür wurden mit analytischen Methoden die physiko-chemischen sowie die technofunktionellen Eigenschaften der Rohstoffe und der vernetzten Biopolymeren untersucht. Verglichen wurden z.B. die IR-Spektren der Ausgangsmaterialien mit denen des vernetzten Biopolymers. Mittels Reaktivextrusion wurden Formkörper hergestellt, deren Eigenschaften durch den Einsatz von geeigneten Weichmachern beeinflusst werden können. Die Temperatur des Extruders sollte möglichst niedrig gehalten werden, d.h. geringer als 90 °C, um unerwünschte Bräunungsreaktionen zu vermeiden. Bei den chemischen Vernetzungen wurden fünf verschiedene Vernetzungsmittel eingesetzt: Glutaraldehyd, Maleinsäureanhydrid, Maleinsäurediethylester, Bernsteinsäureanhydrid und Methylendiphenyldiisocyanat. Die Proben aus der Vernetzung mit Glutaraldehyd weisen einen wasserbindenden Charakter auf und können beispielsweise Einsatz als Hydrogele finden. Die mit Diisocyanaten vernetzten Proben härten im Wasser und können als Füllmaterial Einsatz in der Bauindustrie finden. Aufgrund der starken Vernetzung sind die Proben unlöslich und für die meisten erfolgt der Zersetzungsprozess ab 200 °C. Im Sinne einer Werkstoffbeschreibung wurden alle Proben als Duroplaste eingestuft, da sie keine thermoplastische Eigenschaft aufweisen. Mit dieser Arbeit werden Grundlagen für die Erforschung von Verfahrenswegen für die chemische sowie für die thermische Vernetzung von Polysacchariden und Proteinen gelegt. Die gewonnenen Erkenntnisse können für weitere Arbeiten genutzt werden. / In the present work, the possibilities of conjugation or interactions between polysaccharides, especially hemicelluloses and proteins from different sources of renewable raw materials have been investigated. Sources of polysaccharides are oat spelts xylan and maize spindles. Proteins like acid casein from cow milk and cruciferin, a rapeseed protein isolate, from the canola plant have been used. For the chemical crosslinking, homo-bifunctional reagents (crosslinkers) like glutaraldehyde, maleic anhydride, maleic acid diethyl ester, succinic anhydride, and methylene diphenyl diisocyanate were used. These reagents can react with functional groups of the biopolymers- the hydroxyl groups in the hemicelluloses and amino groups in the proteins. For a thermolinked conjugation of the biopolymers, the reactive extrusion was used as mechanical technique. Both types of biopolymers were successfully blended in a mini-Extruder to form sticks. The plastics characteristics of the sticks could be influenced by the addition of suitable softeners. The extrusion temperature must be kept as low as possible, to avoid the appearance of unwanted brown reactions. To investigate the conjugation of the polysaccharides with casein or cruciferin, the IR spectra of the raw materials with those of the crosslinked biopolymers were compared. Application possibilities of the resulted crosslinked biopolymers have been proposed. Most of the samples are insoluble due to the strong networking after the crosslinking reactions. Their thermal decomposition starts at temperatures around 200 °C. All the samples have been classified as duroplasts since they do not exhibit a thermoplastic characteristic. The work complements basic research about chemical and thermal conjugation between polysaccharides and proteins from renewable raw materials.