Metal colloids have been used for staining glass since hundreds of years. The color of these nano-composites (nano-sized metal particles in a dielectric matrix) is due to a surface plasmon resonance effect of the conductive electrons, which leads to a selective absorbance in the visible range of light. The molar coefficient of absorbance of this effect is in the range of 105–106 l/mol cm, which makes metal colloids very interesting as efficient dyes for colored sol‐gel coatings. Stable colored sol‐gel coatings and highly efficient nonlinear optical materials were the motivation for the development of appropriate synthesis and processing routes, which will be reviewed in this chapter. First, an overview on the linear optical properties of metal colloids in dielectric media shall be given. The sol‐gel synthesis and processing parameters can be well adapted to industrial needs, which will favor further applications. New high-throughput techniques like flat spray coating or flexo printing offer great opportunities for the cost-effective production of colored coated glass in comparably small, individual series.

In Oxycarbidglasern werden die zweiwertigen Sauerstoffatome der SiO2-Tetraeder partiell durch den vierwertigen Kohlenstoff ersetzt, so das verbesserte thermische und mechanische Eigenschaften der Glaser und eine erhohte Resistenz gegen Kristallisation erwartet werden. Oxycarbidglaser weisen Bruchspannungen von 150+-85 MPa bis 550 +- 230 MPa und E-Moduli im Bereich von 100-110 GPa auf. Die thermischen Ausdehnungskoeffizienten liegen bei ca. 3x10 -6 / K und fur die dielektrische Konstante wird ein Wert von 4,4 bei einem dielektrischen Verlustfaktor von ca. 0,1 im Frequenzbereich von 10 Hz bis 10 kHz angegeben. Diese Kenndaten der Oxycarbidglaser lassen Anwendungen als Substrate in der Mikroelektronik und fur Laminate mit erhohter Festigkeit als moglich erscheinen. Derzeit gibt es jedoch uber Sol-Gel keine Technologie zur Herstellung grosformatiger Folien oder anderer groser Formkorper. Das Ziel der Untersuchungen bestand daher darin, ein Verfahren zur Herstellung von Siliciumoxycarbidglasfolien im Labormasstab zu entwickeln und die mechanischen und dielektrischen Eigenschaften der Folien als Funktion der Synthese- und Prozesparameter zu untersuchen.

The sol-gel process allows the preparation of glasses and composites with homogeneities sufficient for optical applications, since phase dimensions can be kept below the level of undesired Rayleigh scattering. This is of special importance for inorganic-organic composites. By other methods, precipitates of inorganic phase may appear within the organic matrix and cause scattering. By chemical control of the particle surface free energy, it is possible to tailor particle size and reactivity, and processing and final properties can be adapted over wide ranges. Using these principles, thick Si02 layers for waveguides, refractive index tailored planar waveguides patterned by photolithography, and active waveguides containing semiconductor quantum dots or metal clusters can be synthesized.

Four-point bending creep behavior of mullite ceramics with monomodal and bimodal distribution of grain sizes was studied in the temperature range of 1320–1400°C under the stresses between 40 and 160MPa. Mullite ceramic with bimodal grain size distribution was prepared using aluminum nitrate nonahydrate as alumina precursor. When γ-Al2O3 or boehmite were used as alumina precursors, mullite grains are equiaxial with mean particle size of 0.6μm for the former and 1.3μm for the latter alumina precursor. The highest creep rate exhibited the sample with monomodal morphology and grains in size of 0.6μm, which is about one order of magnitude greater than that for the monomodal morphology but with grains in size of 1.3μm. The highest activation energy for creep (Q=742±33kJ/mol) exhibits mullite with equiaxial grains of 1.3μm, whereas for sample with smaller equiaxial grains the activation energy is much smaller and similar to mullite ceramics with bimodal grain morphology. Intergranular fracture is predominant near the tension surface, while transgranular more planar fracture is predominant near the compression surface zone.

Die Erzeugung von Strukturen im Bereich von Mikro- bzw. Nanometern ist eine wesentliche Voraussetzung fur die Funktionalisierung von Glasoberflachen. Bis in den Bereich von 0,10 µm stellt die Lithografie die dominierende Strukturierungstechnik dar. Unterhalb dieser Abmessungen verhindern Beugungsphanomene die Erzeugung von noch kleineren Strukturen. Verbesserungen hinsichtlich der Auflosung konnten durch Verringerung der verwendeten Wellenlange erzielt werden. Gleichzeitig erfordert dies die Entwicklung von Linsen, die im Bereich von λ~193 nm hinreichend durchlassig sind. Die lithografische Technik wurde zudem durch weiterfuhrende Ansatze verbessert. Exemplarisch sei hier die Rontgenlithografie, extreme Ultraviolettlithografie, Elektronenstrahllithografie oder Rastersondenlithografie genannt. Rastersondenlithografie ist aufgrund ihrer hohen Auflosung von bis zu 20 nm eine der vielversprechendsten Methoden. Die vorliegende Arbeit beschaftigt sich aus diesem Grund mit der lithografischen Mikro- und Nanostrukturierung unter Verwendung der optischen Rasternahfeldmikroskopie (Scanning Near Field Optical Microskopie (SNOM)). SNOM-Lithografie kombiniert die etablierte Rastersondentechnik mit den Vorteilen der Nahfeldoptik und erreicht auf diese Weise Auflosungen im Bereich von Rasterelektronenmikroskopen (REM). Zudem besitzt die SNOM Methode den Vorteil, dass fur den Betrieb kein Vakuum erforderlich ist. Eine Grosserienproduktion oder grosflachige Herstellung von strukturierten Oberflachen durch direktes Schreiben mit SNOM-Sonden auf ein Substrat ist okonomisch nicht sinnvoll.

Complexation reactions of titanium tetraethoxide [Ti(OEt)(4)] and titanium tetra-n-butoxide [Ti(OBu")(4)] with 3-pentenoic acid (PA) and allylacetoacetate (AAA), in a 1 : 1M ratio, were studied in ethanol solution at room temperature. C-13-NMR and FTIR spectra showed that all PA and AAA completely reacted with both titanium alkoxides. Hydriclosilane compounds such as triethoxysilane and triethylsilane were added to titanium chelate complexes in a 1 : 1M ratio. The investigation of products by C-13- and (SiNMR)-Si-29 and FTIR showed additions of -SiH to the C=C double bond. The hydrolysis of titanium-PA and AAA complexes, by water in 1 : 4 ratios, resulted in released PA in an amount of 10% and AAA of 20%. The stability of hydrolyzed products was investigated by C-13-NMR, "SiNMR, and FTIR. (C) 2004 Wiley Periodicals, Inc.

have become of interest for many reasons. Numerous papers have been issued about the fabrication ofnanoparticles since the book of Gleiter has been published in the 80's [1], where first very interesting results have beendiscussed about materials made from nanoparticles derived by gas phase reactions. For the fabrication of nanoparticles,many routes have been investigated, such as gas phase reactions, e. g. flame pyrolysis as used by Degussa for large scaleproduction or the fabrication ofnanoparticulate silica sols as used and produced by many chemical companies like Clariantor Bayer. In the scientific literature, numerous precipitation methods in liquid phases have been presented [2]. In our ownwork, it was shown that the surface modification of nanoparticles opens up very interesting routes for obtaining processing

The effect of alumina component in diphasic mullite precursors containing alkoxy-derived silica on the crystallization and sintering behavior of compacts was studied. The phenomena observed were characterized using differential thermal analysis (DTA), powder X-ray diffraction (XRD), dilatometry and transmission and scanning electron microscopy (TEM, SEM). In order to change the characteristics of as-prepared gels, the alumina source was varied while keeping the silica source constant. Al(NO3)3·9H2O, γ-Al2O3 and boehmite (γ-AlOOH) were used as the alumina source and TEOS as the silica source. Clear differences were found in the microstructure of sintered samples derived from the precursors with aluminum nitrate nonahydrate in comparison to the samples containing γ-Al2O3 or boehmite (γ-AlOOH). The former exhibited elongated mullite grains embedded into the “equiaxial mullite matrix”. This morphology is due to the overlapping of mullite crystallization and viscous flow sintering temperatures. Transient alumina, either added as γ-Al2O3 or formed in situ by decomposition of boehmite, shifts the mullite formation above the sintering temperature, and enables formation of equiaxial mullite. The smaller are the transient alumina particles, the smaller are mullite grains of sintered bodies.

The crystallization kinetics of mullite formation in diphasic gels containing TEOS-derived amorphous silica and alumina component in different crystalline form and particle size has been studied using quantitative X-ray diffraction (QXRD) with 3:2 mullite as a standard and transmission electron microscopy (TEM). As the source of alumina component, aluminum nitrate nonahydrate, commercial γ-Al2O3 and boehmite (γ-AlOOH) were used. The results were consistent with previous studies which indicated that mullite forms initially by nucleation and growth. During the second slow stage of transformation, mullite with approximate 2:1 composition subsequently converts further into 3:2. This process is the fastest in the precursor with the smallest particle size of alumina, and the slowest in the sample with boehmite-derived alumina. In very fine scale of morphology the conversion of 2:1 mullite started even in the first stage of transformation.

Organically modified cage-like double four-ring spherosilicates have received considerable interest in the construction of nanosized hybrid materials, as well as building units for structural well-defined polymers. This group is extended by perfluoroalkyl ligands containing spherosilicates, synthesized by addition reaction of the octahydridodimethylsiloxyoctasilsesquioxane [H(CH3)2Si]8Si8O20 and heptadecafluorodecyl methacrylate. The resultant liquid spherosilicate substituted with eight terminal perfluoroalkyl groups was characterized by 29Si and 13C NMR spectroscopies and MALDI Time-of-Flight mass spectrometry. Partial substitution of perfluoroalkyl ligands by trimethoxysilyl containing groups provides condensable precursors for the synthesis of hydrophobic and oleophobic materials via the sol-gel process. This new spherosilicate, carrying on average four perfluoroalkyl groups and four trimethoxysilyl groups shows better hydrophobic and oleophobic properties compared with commonly used perfluoroalkyltrialkoxysilanes under identical concentration of perfluoroalkyl chains. In addition a comprehensive literature survey is given on structural well characterized, organically modified cage-like double four-ring spherosilicates.