There is an increasing interest in nanostructured and nanocomposite surface finishings for automotive and aerospace applications. The widespread applicability of these novel materials is based on their unique mechanical, physical, and chemical properties. An advantageous production method is the electrocodeposition (ECD) process from metal plating baths containing dispersed nanoparticles. By using this technique, a broad range of substrate sizes and shapes can be coated cost-effectively. However, the prediction of the amount as well the distribution of nanoparticles within the metal film fails frequently. There is no complete understanding of the particle incorporation mechanism. The goal of this research was to improve the fundamental understanding of the ECD mechanism. In order to identify the forces affecting the codeposition behavior of nanoparticles in a metal matrix, the effects of a variety of interrelated process parameters on the composite film formation have been investigated systematically. Nanocomposites containing metal and metal oxide nanoparticles in a nickel matrix have been prepared by means of ECD from two different types of nickel plating baths, an acidic sulfamate (pH 4.3) and an alkaline pyrophosphate bath (pH 9.5). The effect of deposition conditions on the ECD process was investigated utilizing two electrode configurations, viz. a parallel plate electrode (PPE) and impinging jet electrode (IJE) and different deposition techniques, viz. direct current (DC) deposition, both pulse plating (PP) and pulse-reverse plating (PRP). The surface charge and sedimentation behavior of the nanoparticles in these electrolytes were characterized by zeta potential and stability measurements. The surface charge, hydrodynamic diameter and colloidal stability of the nanoparticles in the nickel electrolytes were mainly affected by the composition and pH of the bath. The particles tend to form agglomerates in both nickel baths. Smaller agglomerates and an improved colloidal stability occurred in the case of the alkaline bath. Composites with a maximum particle content of either ~3.6 vol-% of 13 nm Al2O3 or ~10.4 vol-% of 21 nm TiO2 were obtained using a parallel plate electrode and DC deposition conditions. Both jet plating as well as pulse plating resulted in a distinct increase of the particle codeposition. A maximum incorporation of ~12 vol-% of 50 nm Al2O3 particles in a nickel matrix was achieved using an unsubmerged IJE system, while PP and PRP resulted in composites with particle contents up to 11 vol-% of 13 nm Al2O3. The particle incorporation increased with the particle content of the electrolyte for all deposition conditions studied. A beneficial effect on the amount of codeposited particles was found with decreasing average current density. The Al2O3 and TiO2 particles were found to be negatively charged in the alkaline pyrophosphate bath, and positively charged in the acidic sulfamate bath. It could be shown that negatively charged particles codeposited preferentially within the nickel matrix. The effect of PP and PRP conditions, e.g. pulse frequency, duty cycle and value of the peak current density, on the ECD of Ni-Al2O3 composites was studied using rectangular current pulses in the order of milliseconds. In general, low duty cycles and high pulse frequencies resulted in an enhanced particle codeposition. Using the unsubmerged IJE system, the effects of jet flow rate, particle loading and current density on the particle incorporation were studied. Referring to the experimental results from the ECD of 50 nm alumina with nickel using an IJE system, a kinetic model was developed. Therefore, the particle flux to the electrode was derived from an analysis of the total force acting on the particle in front of the electrode. The model took into account the convective diffusion of particles to the electrode surface, and the effect of gravitational and buoyancy forces on the particle flux. The gravitational force was found to be important for the ECD of 300 nm particles, but not for 50 nm particles. The effect of an external magnetic field on the ECD of Co or Fe3O4 nanoparticles in a nickel matrix has been studied for different current densities, particle contents of the electrolyte and magnetic flux density. The particle incorporation showed a distinct dependency on the orientation of an externally applied magnetic field. While the particle incorporation increased in a perpendicular field (perpendicular with regard to the electrode surface), it decreased in a parallel orientation. The influence of the magnetic field on the ECD of magnetic nanoparticles with nickel was explained by the interplay of Lorentz force and magnetophoretic force. The structure and the properties of the nickel matrix were significantly altered due to the codeposition of nanoparticles. The pure nickel deposits from the sulfamate bath exhibited a strong <100> texture, and those from the pyrophosphate bath a strong <110> preferred orientation. With increasing plating current density and particle incorporation, a variation in the crystallite size and a loss of texture was observed. High resolution TEM imaging proved a complete embedding of nanoparticles by the nickel matrix without any voids. In the case of both nickel baths, the Vickers microhardness showed a tendency to increase with the amount of particle incorporation. The enhanced hardness of the composite films was associated with modifications in the microstructure of the nickel matrix as well as with the nanoparticle incorporation. The wear resistance as examined by linear abrasion test increased with decreasing current density and due to the particle incorporation. Furthermore, the incorporation of magnetic nanoparticles resulted in a distinct increase of the magnetic hardness of the nickel matrix.

The nature and role of defects is of primary importance to understand the physical properties of C and BN single walled nanotubes. Transmission electron microscopy (TEM) is a well known powerful tool to study the structure of defects in materials. However, in the case of SWNTs, the electron irradiation of the TEM may knock out atoms. This effect may alter the native structure of the tube, and has also been proposed as a potential tool for nanoengineering of nanotubular structures. Here we develop a theoretical description of the irradiation mechanism. First, the anisotropy of the emission energy threshold is obtained via density functional based calculations. Then, we numerically derive the total Mott cross section for different emission sites of carbon and boron nitride nanotubes with different chiralities. Using a dedicated STEM microscope with experimental conditions optimised on the basis of derived cross-sections, we are able to control the generation of defects in nanotubular systems. Either point or line defects can be obtained with a spatial resolution of a few nanometers. The structure, energetics and electronics of point and line defects in BN systems have been investigated. Stability of mono- and di- vacancy defects in hexagonal boron nitride layers is investigated, and their activation energies and reaction paths for diffusion have been derived using the nudged elastic band method (NEB) combined with density functional based techniques. We demonstrate that the appearance of extended linear defects under electron irradiation is more favorable than a random distribution of point defects and this is due to the existence of preferential sites for atom emission in the presence of pre-existing defects, rather than thermal vacancy nucleation and migration.

Single-wall carbon nanotubes (SWCNTs) are a fascinating material because they exhibit many outstanding properties. Due to their unique geometric structure, they are a paradigm for one-dimensional systems. Furthermore, depending on their chirality, they can be either metallic or semiconducting. The SWCNT are arranged in bundles of some ten nanotubes with a random distribution of semiconducting and metallic tubes. They are thus one-dimensional objects embedded in a three-dimensional arrangement, the bundles. In this thesis, the metallic ground state of one-dimensional (1D) and three-dimensional (3D) systems is investigated on the basis of SWCNTs, using angle-integrated photoemission spectroscopy. In particular, a transition from a 1D to a 3D metallic system, induced by a charge transfer, is studied on SWCNTs and C60 peapods. In general, the metallic ground state of materials is greatly influenced by correlation effects. In classical three-dimensional metals, electron-electron interaction mainly leads to a renormalization of the charge carrier properties (e.g. effective mass), as described in Landau's Fermi liquid theory. One-dimensional metals are influenced to a greater extent by interactions. In fact, the Landau-quasiparticle picture breaks down due to the Peierls instability. Instead, one-dimensional metals are described by Tomonaga-Luttinger liquid (TLL) theory which predicts unusual properties such as spin-charge separation and non-universal power laws in some physical properties such as the electronic density of states (DOS). Angle-integrated photoemission spectroscopy provides direct access to the DOS and as such directly addresses the power law renormalization of a TLL. It is first shown, that the bundles of single-wall carbon nanotubes indeed exhibit a power law scaling of the electronic density of states is observed as it is expected from TLL theory. The main part of the thesis is devoted to the investigation of the metallic ground state of SWCNTs upon functionalization. In general, functionalization is a controlled modification of the structural and/or electronic properties of SWCNT. It can be carried out e.g. by doping with electron donors or acceptors, by filling the nanospace inside the tubes with molecules or by substituting carbon atoms. First, the behavior of the SWCNT upon chemical doping was probed. The overall modification of the electronic band structure can be explained well by a rigid band shift model. The one-dimensional character of the metallic tubes in the bundle is retained at low doping, but when the semiconducting tubes in the sample are also rendered metallic by the charge transfer, a Fermi edge emerges out of the power law renormalization of the spectral weight, signifying a transition to a three-dimensional metallic behavior. This can be explained by an increased interaction between the tubes in the bundle. A crossover from a Tomonaga-Luttinger liquid to a Fermi liquid is observed. The filling of SWCNTs with C60 molecules leads to the formation of so-called peapods. It raises questions concerning the role of the additional bands originating from the C60 filling in the one-dimensional system. In the pristine state, the states of the C60 filling were found to have no influence on the metallic ground state. The TLL power law scaling of the density of states is observed. The overall interaction between the SWCNT host and the C60 filling is small. Upon doping however, the modified band structure leads to a qualitative change in the crossover from a TLL to a Fermi liquid. Upon doping, also states in the conduction band of the C60 are filled. The evolution of the power law scaling at intermediate doping can be interpreted as an opening of an additional conduction channel of one-dimensional metallic chains of C60 inside the tubes. This is in good agreement with transport experiments. Upon further doping, a Fermi edge similar to the highly doped SWCNTs is observed.

In dieser Arbeit werden zwei Schwerpunkte behandelt. Zum Einen soll der Einsatz nanoskaliger Materialien als Funktionskomponenten in Elektrolumineszenzbauteilen beschrieben werden. Dabei wird in einem ersten Aufbau ein transparenter Nanokompositfilm als emittierende Schicht in einem, den organischen Leuchtdioden, analogen Aufbau eingesetzt, während in einer zweiten Struktur eine transparente Elektrode, die auf nanoskaligen Kohlenstoffmaterialien (Kohlenstoffnanoröhren bzw. Graphenen) basiert, hinsichtlich ihrer Eignung als Alternative zu etablierten transparenten Elektroden untersucht werden soll. In weiterführenden Arbeiten werden die Erfahrungen aus der Graphensynthese auf die Generierung poröser, funktionalisierter Kohlenstoffmaterialien angewendet. Verbindend, wird die Röntgenkleinwinkelstreuung eingesetzt, um in vergleichenden Untersuchungen möglichst detailierte Informationen über die jeweiligen Systeme zu erhalten.

Mitochondria are an attractive target for the design of cancer therapy. One of the mechanisms by which chemotherapeutics destroy cancer cells is by inducing apoptosis through extrinsic or intrinsic apoptotic pathways. Extrinsic pathways target cell surface receptors whilst intrinsic pathways target mitochondria. Several studies have shown cancer cell destruction through the extrinsic pathways, which target cancer-specific overexpressed growth factor receptors on the cell membrane. Although the mitochondria dependent apoptotic process is well understood, its application in cancer therapy is still not well developed. Therefore, to design an effective cancer therapy targeting mitochondria, a good understanding in mitochondria dependent apoptotic process is required. Recent developments in nanotechnology have enabled live cell investigations and non-destructive methods to obtain cellular information. The availability of such information would assist to design methods of targeted apoptosis induction. In view of this, I report on studies towards development of cancer therapy where nanoparticles (NPs) were targeted to human cell mitochondria for two purposes: (a) development of cell-imaging tools to investigate the fundamental cell biological pathways inside cells and (b) induction of apoptosis by targeting nanoparticles to mitochondria. Current medical and biological fluorescent imaging methods are mainly based on dye markers, which are limited in light emission per molecule, as well as photostability. Consequently, NPs are gaining prominence for molecular imaging because of their strong and stable fluorescence. Additionally, in order to get insight of mitochondrial molecular information, I investigated the use of optical properties of gold nanoparticles (Au NPs) for surface enhanced Raman spectroscopy (SERS). In this study, two types of Au NPs - nanospheres (Au NS) and nanorods (Au NR) were investigated. Results from this study showed the enhancement effect of Au NPs in Raman spectra of mitochondria, especially in the region from 1500 to 1600 cm-1. In this region, normal Raman spectra of mitochondria showed the presence of some understated Raman peaks probably due to the excitation wavelength dependence. Au NRs showed a larger enhancement effect than Au NS with respect to the penetration depth of the plasmonic nearfield enhancement effect. Although, the details of the enhancement mechanism are beyond the current studies, Au NPs could be enhancing vibrations of aromatic residues in proteins. This study therefore showed that Au NPs could enhance Raman spectra of mitochondria and in addition the shape of the nanoparticles had a significant effect on SERS spectra. In living cells, I investigated some transfection methods and targeting of NPs to mitochondria or cytosolic actin subunits. I tested the performance of three transfection reagents to deliver nanodiamonds (NDs) into living cells. Antibody functionalized NDs were targeted to mitochondria or cytosolic actin subunits. Three transfection reagents were used: cationic liposomes PULSin™, the cell penetrating peptide protamine, and oligosaccharide modified polypropylene imine (PPI) dendrimers. Fluorescence imaging results revealed that dendrimers were the most efficient in delivering ND conjugates to targeted organelles. Protamine-mediated transfections appeared to target ND conjugates to intended organelles, although there was a tendency of unfunctionalized NDs to be directed to the nucleus. PULSin™-mediated transfection formed ND aggregates regardless of the functionalization moiety. This reflected the unsuitability of the cationic liposome to mediate ND transfections. Further, I investigated the potential use of Au NPs for cell imaging and photothermal lysis of mitochondria inside cells. Just as above, I also tested the performance of the three-transfection reagents mentioned above on transfection capacity of Au NPs into living cells. Using transmission electron microscopy (TEM), oligosaccharide modified dendrimers showed the best transfection of functionalized Au NPs. Further experiments explored the use of the nearfield enhancement effect of Au NPs in combination with low-level laser irradiation (LLLI) to induce apoptosis in living cells. Analysis of the apoptotic process using cytochrome c release showed that Au NPs induced apoptosis most probably through mechanical disruption of the outer mitochondrial membrane. However, apoptosis was significantly accelerated in cells with mitochondrially targeted Au NRs than in cells without Au NRs. This study showed successful targeting of Au NPs to mitochondria in living cells, and demonstrated the potential of using Au NPs in combination with laser irradiation to induce the mitochondria dependent apoptotic pathway. In conclusion, the potential use of Au NPs in SERS of mitochondria and the application of NDs for cell imaging of intracellular organelles were demonstrated. Lastly, Au NPs were targeted to mitochondria in living cells and could induce apoptosis due to mechanical disruption of the outer mitochondrial membrane. Consequently, application of low-level laser irradiation to Au NP transfected cells accelerated the apoptotic process.

New challenges in nanotechnology arise in the assembly of nanoobjects into three-dimensional superstructures, which may carry synergetic properties and open up new application fields. Within this new class of materials nanostructured, porous functional metals are of great interest since they combine high surface area, gas permeability, electrical conductivity, plasmonic behavior and size-enhanced catalytic reactivity. Even though a large variety of preparation pathways for the fabrication of porous noble metals has already been established, several limitations are still to be addressed by research developments. The new and versatile approach that is presented in this work makes use of a templatefree self-assembly process for the fabrication of highly porous, metallic nanostructures. Thereby, nanochains are formed by the controlled coalescence of noble metal NPs in aqueous media and their interconnection and interpenetration leads to the formation of a self-supported network with macroscopic dimensions. Subsequently, the supercritical drying technique is used to remove the solvent from the pores of the network without causing a collapse of the fragile structure. The resulting highly porous, low-weighted, three-dimensional nanostructured solids are named aerogels. The exceptional properties of these materials originate from the conjunction of the unique properties of nanomaterials magnified by macroscale assembly. Moreover, the combination of different metals may lead to synergetic effects regarding for example their catalytic activity. Therefore, the synthesis of multimetallic gels and the characterization of their structural peculiarities are in the focus of the investigations. In the case of the developed preparation pathways the gelation process starts from preformed, stable colloidal solutions of citrate capped, spherical noble metal (Au, Ag, Pt, Pd) NPs. In order to face various requirements several methods for the initiation of the controlled destabilization and coalescence of the nanosized building blocks were developed and synthesis conditions were optimized, respectively. Multimetallic structures with tunable composition are obtained by mixing different kinds of monometallic NP solutions and performing a joint gel formation. The characterization of the resulting materials by means of electron microscopy reveals the formation of a highly porous network of branched nanochains that provide a polycrystalline nature and diameters in the size range of the initial NPs. Furthermore, synthesis conditions for the spontaneous gel formation of glucose stabilized Au and Pd NPs were investigated. In order to gain a detailed knowledge of the structural properties of bimetallic aerogel structures a versatile set of characterization techniques was applied. A broad pore size distribution dominated by meso- and macropores and remarkably high inner surface areas were concluded from the N2 physisorption isotherms and density measurements. As investigated, a specific thermal treatment could be used to tune the ligament size of Au-Ag aerogels, whereas Au-Pd and Pt-Pd structures provide thermal stability under mild conditions. Further investigations aimed to the enlightenment of the elemental distribution and phase composition within the nanochains of multimetallic gel structures. The different approaches provide complementary and consistent results. Phase analyses based on XRD measurements revealed separated phases of each metal in the case of Ag-Pd and Au-Pd aerogels. They further proved the possibility of temperature induced phase modifications that lead to complete alloying of Au and Pd. In addition, separated domains of Pt and Pd were established from the EXAFS analysis of the corresponding aerogel. STEM EDX high resolution elemental mappings confirmed the separated domains of different metals in the case of Au-Pd and Pt-Pd aerogels. Moreover, a complete interdiffusion and alloy formation of Au and Ag within the corresponding aerogel structure is suggested from STEM EDX results. Finally, the presented investigations further promote the field of metallic aerogels by addressing the challenging issue of processability and device fabrication. Hybrid materials with organic polymers as well as various kinds of coatings on glass substrates and glassy carbon electrodes were prepared whereas the network structure was preserved throughout all processing steps. Moreover, it was illustrated that the NP-based aerogels carry metallic properties as expressed by their low Seebeck coefficients and high electrical conductivities.

This work focuses on the development of metal nanowire networks for the use as transparent electrodes in small-molecule organic solar cells. Broad adoption of organic solar cells requires inexpensive roll-to-roll processing on flexible, lightweight substrates. Under these conditions, traditional metal oxide electrodes suffer from significant drawbacks such as brittleness and cost. In contrast, metal nanowire networks provide properties more suitable for high-throughput processing and thus, are investigated here as an alternative. They combine the high-conductivity of metals with the advantage of optical transparency found in aperture-structured networks. The process chain from nanowire deposition to cell integration is examined with silver and copper nanowire material. Two techniques are presented for deposition. While dip-coating is investigated in detail, including a discussion of the most important parameters, spray-coating is demonstrated as an alternative for large area applications. Since the nanowires are barely conductive after deposition, post-treatment steps are used to achieve a performance comparable to standard metal oxide films such as tin-doped indium oxide (ITO). The inherent roughness of nanowire electrodes is addressed by using a conductive polymer as a planarization layer. On top of optimized electrodes, small-molecule organic solar cells are deposited with a UHV thermal evaporation process. Completed cells are tested and performance is found to be comparable to the used standard transparent electrodes. Additionally, a new approach to achieve aligned nanowire network structures is demonstrated. The additional degree of order is used to illustrate optical effects of silver nanowire networks. Furthermore, these aligned networks exhibit anisotropic conductivity. This effect is discussed and simulations are performed to reproduce the observations. The freedom of network design is used to achieve superior conductivity compared to standard random structures. / Im Fokus dieser Arbeit steht die Entwicklung von Metall-Nanodraht-Netzwerken für die Anwendung in transparenten Elektroden für organische Solarzellen. Eine breite Verwendung von organischen Solarzellen setzt eine kostengünstige Rolle-zu-Rolle Fertigung auf flexiblen und leichten Substraten voraus. Unter diesen Bedingungen leiden traditionell verwendete Metalloxid-Elektroden unter erheblichen Nachteilen, wie Brüchigkeit und Preis. Im Gegensatz dazu zeigen Metall-Nanodraht-Netzwerke deutlich bessere Eigenschaften und werden deshalb hier als alternative Elektroden untersucht. Die Netzwerke kombinieren die hohe Leitfähigkeit von Metallen mit einer hohen Transmittivität in Folge der netzwerkbedingten Apertur. Die Prozesskette von der Nanodraht-Abscheidung bis zur Zellintegration wird für Silber- und Kupferdrähte untersucht. Zwei Techniken für die Abscheidung werden präsentiert. Ein Tauchverfahren wird detailliert untersucht und die zugehörigen Parameter werden diskutiert. Für große Flächen wird eine Sprühbeschichtung als Alternative aufgezeigt. Da die abgeschiedenen Netzwerke eine schlechte Leitfähigkeit besitzen, sind Nachprozessierungsschritte notwendig um gute Leitfähigkeiten im Bereich von üblichen Elektroden wie Indium-Zinn-Oxid (ITO) zu erreichen. Die Rauheit der Nanodraht-Elektrode wird mit Hilfe einer glättenden Polymerschicht behoben. Auf den optimierten Elektroden werden organische Solarzellen aus kleinen Molekülen in einem thermischen UHV-Prozess abgeschieden. Die Zellen werden getestet und zeigen Eigenschaften vergleichbar zu üblichen transparenten Elektroden. Zusätzlich wird ein neuer Ansatz zur Herstellung von ausgerichteten Netzwerkstrukturen demonstriert. Der zusätzliche Grad an Ordnung wird für die Untersuchung von optischen Effekten an Silberdraht-Netzwerken genutzt. Weiterhin zeigen diese ausgerichteten Netzwerke eine anisotrope Leitfähigkeit. Dieser Effekt wird diskutiert und Simulationen werden durchgeführt, um die Beobachtungen zu verifizieren. Die Freiheit in der Netzwerkstruktur wird für eine Verbesserung der Leitfähigkeit genutzt.

Electroless plating is a metal deposition technique widely used in the coating industry. It is the method of choice to plate substrates with complex geometries and nonconductive surfaces, such as polymers and ceramics, since it is based on a chemical reduction in solution rather than on an external electrical energy source like the electroplating method. Among others, examples of well-established applications are the electroless deposition of decorative metal coatings such as gold and silver, wear and corrosion resistant nickel coatings, particularly to coat drive shafts, rotors, and bathroom fixtures, as well as the electroless deposition of copper in electronic devices as diffusion barriers and conductive circuit elements. In the academic research, electroless plating is extensively used thanks to its low cost, simple equipment and versatility that allow rapid prototyping. Two common applications are the coating of small particles and the selective plating of flat surfaces. Metal coated ceramic particles are of enormous interest in many scientific fields, e.g. fluorescent diagnostics in biochemistry, catalysis, and fabrication of photonic crystals. Metal coated ceramic nanoparticles and microparticles are also gaining attention as potential candidates in the fabrication of higher quality metal matrix Composites, which is one of the applications addressed by this work. Metal coated ceramic particles are easier to integrate in metal matrix composites, avoiding aggregation caused by the low wettability of the particles by the matrix metal, and are potentially shielded from oxidation and undesired chemical reactions that take place at the interface between the particles and the metal Matrix. Electroless plating is an autocatalytic process, meaning that the deposited metal atoms catalyze the deposition of further metal. In order to achieve the first stable metal seeds on a surface, the latter has to be functionalized. Without this functionalization the metal ions in the electroless plating bath are not reduced or are simply reduced to metal nanoparticles in solution. The traditional activation step for nonconductive surfaces is performed by immersion of the substrate in palladium based solutions, which is very time-consuming and extremely expensive. In particular for nanoparticles, previous work showed that at least 1015 Pd atoms/cm2 are required for a uniform activation of a surface, meaning that in the case of nanoparticles with a surface area of about 100 m2/g are necessary 6.4 g of palladium for each gram of substrate. Assuming a price of about 150 €/g (laboratory scale) for palladium nanoparticles and palladium precursors used for surface activation, it results that the activation of 1 g of nanoparticles costs around 1000 €. Such costs are suboptimal considering the typical production scale, and therefore alternative functionalization methods are desired. In this work, new organic-based functionalization methods based on (3-mercaptopropyl)triethoxysilane to functionalize oxide particles, 3-aminopropylphosphonic acid to activate carbide particles and a substrate-independent method based on the bioinspired polydopamine are developed and investigated in detail, together with the respective electroless plating baths, which often have to be specifically tailored regarding the different reactivity of the different molecules and substrates. Furthermore, in the fabrication of metallic patterns on substrates by electroless plating, new, simple, and cost-effective activation and metal deposition processes are desired. In this work, two new methods are presented, one based on the printing of (3-mercaptopropyl)triethoxysilane by microcontact printing, the other based on the capillary force lithography of polymethylmethacrylate.

Das Ziel der vorliegenden Arbeit war die Entwicklung eines neuartigen Abscheideverfahrens für Dünnschichten aus Polymer-Metall-Nanokompositen sowie die Charakterisierung sensorischer und antibakterieller Eigenschaften von ersten, mit diesem System abgeschiedenen Komposit-Schichten . Durch den Einbau eines rotierenden Probenhalters zwischen den beiden Plasmaquellen ist es möglich, Plasmapolymere und metallische Nanopartikel als Einzelschichten, Komposite oder Multischichten abzuscheiden. Mit der Gasflusssputterquelle werden Silber-Nanopartikel einer Größe von 1,8…20 nm mit einer Verteilungsbreite der gewichteten Normalverteilung von 0,1…2,7 nm durch Kathodenzerstäubung und anschließende Agglomeration der Cluster in der Gasphase generiert. Die Entladungsbedingungen, welche durch die Elektronentemperatur und -dichte charakterisiert werden, zeigen eine sprunghafte Änderung bei Drücken von 70…85 Pa und einer Spannung von 550 V. Ab einem Gasfluss von 3 slpm kehrt sich die Proportionalität zwischen zugeführter elektrischer Leistung und Elektronentemperatur um. Dies wird durch die vermehrte Emission von Sekundärelektronen erklärt. Die abgeschiedenen Partikel sind aus verschieden orientierten Clustern aufgebaut. Durch Kühlung des Substrates wurde nachgewiesen, dass eine Agglomeration auf dem Substrat nur bei Gasflüssen von 5 slpm stattfindet. Anhand der Auswertung von faktoriellen Versuchsplänen wurde gezeigt, dass der Gasfluss auf die Partikelgröße und Abscheiderate den größten Einfluss hat. Die Präkursoren Styrol, Methylmethacrylat und 3-Methyl-1,2-butadien wurden durch Plasmapolymerisation in einer 60 MHz-Linearquelle als dünne, homogene Schichten im nm-Bereich abgeschieden. Aus den Emissionsspektren von Argon konnten, unter Verwendung des Stoß-Strahlungs-Modells, Elektronendichten von 6*1010…1,5*1011 cm-3 und Elektronentemperaturen von 3…9 eV in Abhängigkeit von der Verweilzeit der Monomermoleküle im Plasma sowie des Energieeintrages berechnet werden. Die Elektronen haben bei Energieeinträgen oberhalb von 6*107 J/kg genügend Energie, um -Bindungen des Kohlenstoffs in der Gasphase zu spalten. Die freien Radikale initiieren Oxidationsreaktionen, was zur Bildung von Carbonylverbindungen in Schichten aus Styrol- und Isoprenplasmapolymeren führt. Die mit XPS-Messungen gefundenen hohen Sauerstoffgehalte der Plasmapolymer-Schichten konnten durch Kontaktwinkelmessungen bestätigt werden. Die Quellungsmessungen in organischen Lösungsmitteln (Aceton, Ethanol, Chloroform, Toluol) mit reflektometrischer Interferenzspektroskpie bestätigen die Tendenzen der Kontaktwinkelmessung im Fall von Styrol und Methylmethacrylat. Die Abscheiderate der Plasmapolymere wird besonders durch den Energieeintrag beeinflusst. Dabei zeigt sich nur bei Isopren eine deutliche Auswirkung der Abbaureaktionen.Die Härte der Isopren-Schichten korreliert ebenfalls mit der Elektronendichte. Die Perkolationsschwelle der Silber-Plasmapolymer-Nanokomposite liegt bei einem Füllgrad von 57 %, was typisch für Partikel mit geringem Aspektverhältnis ist. Die Schichten reagieren selektiv auf Dämpfe der Lösungsmittel. Bisher war die Langzeitstabilität von Membranen zur Trinkwasseraufbereitung durch Ultrafiltration durch das starke Wachstum von Mikroorganismen auf der Membranoberfläche eingeschränkt. Dies konnte durch die Beschichtung mit Silber-MMA-Kompositen verbessert werden. Durchflussmessungen an behandelten Membranen sowie elektronenmikroskopische Aufnahmen bestätigen die gute antibakterielle Wirkung der Beschichtung.

Within the field of modern technology, nanomatrials, such as nanoparticles (NP), nanorods (NR), quantum dots (QD) etc. are, probably, the most prominent and promising candidates for current and future technological applications. The interest in nanomaterials arise not only form the continuous tendency towards dimensions minimisation of electronic devices, but also due to the fact, that new and, often, unique properties are acquired by the matter at the length scale between 1 and 100 nm. The ability to organize nanoparticles into ordered arrays extends the range of useful NP-based systems that can be fabricated and the diversity of functionalities they can serve. However, in order to successfully exploit nanoparticle assemblies in technological applications and to ensure efficient scale-up, a high level of direction and control is required. Recently, block copolymers (BCP) have attracted much attention as a powerful and very promising tool for creation of nanoscale ordered structures owing to their self-assembling properties. In addition, these systems offer the possibility to fabricate nanostructured composite materials via incorporation of certain nanoadditives (i.e. NPs). The concept is that by selective inclusion of the nanoparticles into one of the blocks of a self-assembling copolymer, the nanoparticles are forced into a defined spatial arrangement determined by the phase morphology of the block copolymer. In present work self-assembling phenomena of block copolymers was exploited to fabricate binary (NP/BCP) and ternary (NP1/NP2/BCP) composites, filled with pre-synthesized nanoparticles of various nature. Polystyrene-block-polyvinylpyridine block copolymers (PS-b-PVP) of various composition and molecular weight were used for fabrication of nanocomposites. The first part of the thesis focuses on fabrication of functional BCP-based composites containing magnetic nanoparticles (MNP), selectively assembled within one of the blocks of BCP matrix. Magnetic nanoparticles (MNPs) were selected among others since, as for today, there is the least number of successful results reported in literature on their selective incorporation into one of the phases of a BCP matrix. From the application point of view fabrication of periodic arrays of “magnetic domains” with periodicity on nanometer scale is also of interest for potential use in high-density magnetic data storage devices. For this purpose, ferrite-type MNP (Fe3O4, CoFe2O4) having apparent affinity toward polyvinylpyridine (PVP) phase were prepared using simple one-pot synthesis. Highly selective nanoparticles segregation into PVP domains of BCP was achieved owing to the presence of sparse stabilizing organic shell on the nanoparticles surface. Importantly, as-prepared MNPs did not require any additional surface modification step to acquire affinity towards PVP phase. Appropriate selection of annealing conditions allowed to produce patterns of nearly perfect degree of lateral order over relatively large surface large area (more than 4 sq µm). The second task of present work was fabrication of ternary NP1/NP2/BCP hybrid composites with two different types of nanoparticles being selectively localized in different microdomains of phase segregated block copolymer matrix. So far as only few studies have been reported on developing of approaches toward ternary composites, creation of alternative and straight forward routes toward such systems is still a challenge. In the frame of this part of present work, silver nanoparticles (AgNPs) covered with polystyrene shell were prepared, with the purpose to be incorporated into polystarene phase of phase separated PS-b-PVP block copolymer matrix. Two different approaches were tested to achieve desired three-component system. First, supposed simple blending of block copolymer and two kinds of nanoparticles having specific affinity toward different blocks of BCP in common solvent. After preparation of MNP/AgNP/BCP composite thin film and subsequent solvent vapour annealing, different domains of microphase segregated PS-b-PVP BCP were filled with different type of nanoparticles. Alternatively, step-wise approach for nanoparticles incorporation was developed and implemented for successful selective nanoparticles incorporation. For this purpose polystyrene stabilized AgNPs (i.e. NP1) were initially mixed with PS-b-PVP BCP to produce composite thin films having nanoparticles selectively located within PS microdomains, while citrate-stabilized second type nanoparticles (i.e NP2) were deposited from their aqueous solutions into PVP domains of AgNP/PS-b-PVP composites. By partition of nanoparticles incorporation procedure into two distinct steps it was also possible to increase effective loading of each type of NPs into BCP matrix.