The cubeoctameric silicate anion is one of compounds which can be used as a building block for constructing nanostructures of materials. This paper deals with the synthesis and reactivity of the silicate anion and organic-inorganic hybrid and inorganic multi-component porous materials produced from the anion.

In electronics packaging, underfill encapsulants are needed to improve package reliability in flip-chip devices. The underfill generally consists of an epoxy resin highly filled with silica particles and is designed to reduce the stress arising from the difference in the thermal expansion between the solder bumps and the substrate. Currently, concerns about the flow of the silica particles and surface phenomena are arising as electronics packages reduce in size. Newly developed epoxy-functionalized octameric silsesquioxanes provide an intriguing alternative to current formulations. These single-phase inorganic/organic hybrid materials may have properties similar to filled materials without the complications from the rheology of filled materials. The physical properties of the functionalized silsesquioxanes are measured with respect to the critical parameters for underfill materials. Measurements of properties such as the coefficient of thermal expansion and density are performed to evaluate the suitability of these materials as potential underfill encapsulants.

A series of Polyhedral Oligomeric Silsesquioxane (POSS) monomers bearing reactive hydroxyl functionalities, suitable for incorporation into step-growth polymers, is described. These monomers are difunctional in nature and are particularly well suited for use as chain extenders in the synthesis of polyurethanes. This work describes the synthesis of these POSS monomers and their incorporation into a series of polyurethanes. Preliminary thermal, mechanical and rheological data for the POSS containing polyurethanes will also be discussed.

The reaction of {(BuSn)12014(OH)6}(OH)2 and 2-acrylamido-2-methyl-1-propanesulfonic acid yields bifunctional nanobuilding blocks, {(BuSn)12,014(OH)6)(AAMPS)2, which carry highly polymerizable acrylamido groups. In such species, the functionalization with polymerizable groups is achieved through electrostatic interaction; the charge compensating anions AAMPS− being located at both poles of the {(BuSn)12O14(OH)6}2+ macrocation. Free radical polymerization of these nanobuilding blocks in THF yields an insoluble material. Solid state 13C CP-MAS NMR of the insoluble fraction (∼70%) indicates that the polymerization of the acrylamido groups is complete. Solid state 119Sn MAS NMR shows that the oxo-hydroxo butyltin core of the nanobuilding blocks is fully preserved in the final material.

The sol-gel processing of appropriated molecular precursors easily leads to a variety of hybrid organic-inorganic materials with intrinsic properties. This approach is increasingly becoming an interesting way to prepare heterogeneous catalysts. The paper will focus on the use of hybrids for the preparation of selective catalytic materials. Two examples of the use of hybrid polysilsesquioxanes polymers will be given. i) The tailoring of the pore structure of silicas, under mild reaction conditions, based on the temporary introduction of different organic substructures in the hybrid network of polysilsesquioxane gels will be discussed. ii) Also the preparation of new chiral hybrid supports for enantioselective catalysis will be presented.

A nonhydrolytic sol-gel method was used to incorporate siloxane and cyclotriphosphazene units within metal oxides. The degree of mixing of the components was investigated by EDX, XPS, and 29Si and 31P solid-state NMR. The NMR data confirmed the presence of Si-O-M and PO- M bonds.

Nanocrystalline titanium dioxide has been synthesized using a sol-gel technique followed by hydrothermal growth at temperatures in the range 190-270°C. Thin films of these colloids were studied using x-ray diffraction (XRD), scanning electron microscopy (SEM), and nitrogen adsorption/desorption. Self-organization of the nanocrystalline particles in regular arrays was observed in films made from colloids autoclaved at lower temperatures. We present herein initial photovoltaic performance of these semiconducting films used as working electrodes in a dye-sensitized solar cell.

A general route to organic-inorganic hybrids with nanophase morphologies has been elaborated with the objective of ultimately templating nanoporosity in organosilicates. A key feature of the hybrids is the preparation of well-defined macromolecules bearing significant functionality to interact with the organosilicates. The use of living polymerization methods allows the synthesis of polymers with accurate control of molecular weight, polydispersity, and chain ends. We have demonstrated living polymerizations from dendritic and hyperbranched initiators to produce controlled branched, star and hyperstar macromolecules. These polymers are used as structure directing agents to organize organosilicates into nanostructures. Once the macromolecular species has templated or organized the inorganic component, the organic polymer can be selectively removed by thermolysis to produce a nanoporous inorganic structure. The size and shape of the pores are similar to those of the initial hybrid morphology. A significant reduction in the dielectric constant of these insulating materials is achieved simply by replacing a portion of the glass matrix with air which has a dielectric constant of 1.

Self-assembly of organic-inorganic molecules into highly order nanostructured architectures have attracted increasing attention because these materials provide a rich source for scientific research and technological applications. We report the synthesis of an oriented silica mesostructured film by ferrocenyl surfactant templating using a spin coating method. The oriented silica meso-structure film was prepared as follows: tetraethoxysilane (TEOS) was partially hydrolyzed by a substoichiometric amount of pure water mixed with ethanol (EtOH) under acidic condition. The solution became homogeneous as the hydrolysis proceeded, then, ferrocenyl TMA was added, the mixture was stirred at room temperature for about 1 hour, and finally, the film was obtained by spin coating the hybrid sol. X-ray diffraction pattern of the film showed that the film oriented in a lamellar structure with (100) d-space of 36.3 A. The optical and electronic conductivity properties of the film have also been explored.

Amorphous microporous mixed oxides (AMM) are materials characterized by a narrow micropore distribution, high porosity, definable surface polarity and homogeneous elemental distribution (absence of domains). They are prepared by a modified Sol-Gel procedure in a single preparation step. Membranes prepared from these materials are selective heterogeneous catalysts, whose microstructural properties can be adjusted to the reaction conditions. Here it is shown, how the surface polarity of the membrane affects the hydrogenation properties.

Vinyl-MCM-41 has been synthesized by a direct synthesis from the corresponding organosiloxane precursors. The location of vinyl groups on the internal channel surfaces of the mesoporous silicate sieves was confirmed by small angle neutron scattering (SANS) experiments using contrast matching techniques. To investigate further modification of the vinyl groups, bromination reactions were carried out on vinyl-MCM-41 samples in dichloromethane, carbon tetrachloride, and in a gas-phase reaction. With dichloromethane as a solvent, the bromination rate increased with increasing pore diameter. A strong dependence of the reaction rate on the presence and type of solvent molecules was observed. While gas-phase bromination was complete within 40 minutes, the reaction required several days for completion in dichloromethane and was even slower in the nonpolar solvent, carbon tetrachloride.

After over a decade of research, the efficient synthesis and processing of layered organic/inorganic nanocomposites that mimic bone and shell structures remains an elusive goal of the materials chemist. We report on a rapid, efficient, continuous method to form layered nanocomposites via evaporation induced supramolecular self-assembly (SSA). During dip coating of a homogeneous sol containing alcohol or ether solvents, silica precursors, organic monomers, initiators and surfactant (at an initial concentration below cmc), solvent evaporation induces the formation of micellar structures that co-organize with silica to form cubic, hexagonal or lamellar mesophases. The organic monomers and initiators are solvated within the hydrophobic micellar interiors. Subsequent photo or thermal polymerization and washing results in a silica/polymer thin film nanocomposite. The microstructural and physical characteristics of these materials will be discussed in the context of potential applications as abrasion resistant coatings and optical hosts.

The insoluble, strongly hydrogen bonded organic pigment of 3,6-bis-(4-chlorphenyl)-l,4- diketopyrrolo [3,4-c] pyrrole was transiently blocked by adding carbamate groups, and consequently incorporated into organic-inorganic hybrid matrices by a sol-gel process. The homo- (pigment-pigment) and hetero-intermolecular (pigment-matrix) interactions were found to control both the assembly and dispersion of pigment molecules in the hybrid coating films. A weaker interaction between matrices and pigment molecules results in aggregation of the carbamate pigment in the methyl-silicate films. A stronger interaction forms a homogenous dispersion and coloration of the phenyl-silicate films. The as-prepared methyl- and phenylsilicate films doped with the organic pigment were distinguished by a morphology change and a blue (hypsochromic) shift in absorption from 550 to 460 nm. Thermal treatment can remove the carbamate groups and in-situ form the organic pigment in the hybrid films.

The simple spin casting technique has been successfully used for producing mesoporous thin films on glass substrate. The films are found to be homogeneous and continuous in a large size scale, however, the mesostructural phase of the film has been controlled systematically among amorphous (A), one-dimensional hexagonal (1-dH), cubic (C) and Lamellae (L) by increasing surfactant to TEOS concentration ratio in the casting solution. The 1-dH as well as cubic structure is thermally stable after the calcination so that a mesoporous thin film is obtained by surfactant removal. The solution additives of 1-propanol and 2-butanol might play a roll in the direct formation of the primitive cubic phase in the film form which has never been obtained.

Composite materials consisting of polymeric matrix materials and natural or synthetic layered minerals like clays were prepared by using special compatibilizing agents between the two intrinsically non-miscible materials. These compatibiliseres are block- or graft copolymers combining one part of the polymer identically and/or completely miscible with the organic polymer (matrix compound) an another part compatible/miscible with the natural mineral. The interaction between the first part of the compatibiliser is preferentially an ionic interaction or an interaction via H-bonds. This interaction leads to a separation of the mineral into single sheets and a subsequent homogeneous incorporation of these sheets into the polymer matrix material.

Our research is focused on developing inorganic molecular sieve membranes for light gas separations such as hydrogen recovery and natural gas purification, and organic molecular separations, such as chiral enantiomers. We focus on zinc phosphates because of the ease in crystallization of new phases and the wide range of pore sizes and shapes obtained. With our hybrid systems of zinc phosphate crystalline phases templated by amine molecules, we are interested in better understanding the association of the template molecules to the inorganic phase, and how the organic transfers its size, shape, and (in some cases) chirality to the bulk. Furthermore, the new porous phases can also be synthesized as thin films on metal oxide substrates. These films allow us to make membranes from our organic/inorganic hybrid systems, suitable for diffusion experiments. Characterization techniques for both the bulk phases and the thin films include powder X-ray diffraction, TGA, Scanning Electron Micrograph (SEM) and Electron Dispersive Spectrometry (EDS).

The monitoring of different reactions such as the stabilization of the alkoxides with polymerizable organic additives, the building of the inorganic network during the hydrolysis process, and in a same manner, the polymerization of the organic additives, can be of great importance for the development of hybrid materials with improved processability.

NIR spectroscopy is a very versatile technique but lacks of specificity. IR and Raman give more interpretative results but are not always easy to run on a process. We used both techniques along with chemometric tools to extract relevant information from our processes. Then 2D correlation allowed to benefit from the specificity of IR and Raman to develop robust NIR methods able to be used on line to control the different steps of the sol-gel process.

The hydrolysis of mixed species of titanium containing chloro, isopropoxo and methacrylato ligands will be discussed in terms of mechanism occuring during the sol-gel process.

Dendritic polymers have been used as soluble templates/unimolecular reactors from which nano-clusters of inorganic compounds were synthesized. These organic/inorganic, dendrimerbased hybrid species or “nanocomposites” display unusual properties, i.e., their solubility is deterrnined by the properties of the dendrimer molecules. Since it has been established that there is no covalent bond between the dendrimer host and the inorganic guest, these observations suggest that the guests are physically and spatially restricted by the dendrimer shell. However, this structure has not been verified. In this investigation a preliminary understanding of the physical structure of these dendrimer-based nanocomposites was sought. A model system of PAMAM dendrimer-copper sulfide nanocomposites was studied in various stages of its formation using a combination of small angle X-ray and neutron scattering experiments. The results suggest that little perturbation of the dendritic species occurs on complexation, but indicate that a secondary supermolecular aggregation phenomena occurs within nanocomposite solutions.

The structure and certain properties of Class {I} and Class {II} nanocomposites based on silica-poly(ethylene)oxide blends are described herein. The detailed structure of the silica framework of Class {I} materials is depicted by combining 29Si NMR and X-Ray diffractometry, while the properties of the polymer phase are obtained from 13C NMR and thermal analysis (DSC). These experiments demonstrate the significant influence of the catalyst on the silica structure (compositional and positional disordering). Moreover, the dynamic properties of the polymer phase are greatly effected by the silica morphologies (silica surface area and degree of phase interpenetration). Class {II} materials were also studied. They have rubbery properties and can be used as a matrix to absorb large quantities of solvents. Hence, combining uniaxial anisotropy (through unidirectionnal strain) with deuterated molecules enabled the study of these materials by quadrupolar NMR. This technique is very sensitive to the local anisotropy of the samples used and leads to a better understanding of supramolecular interactions between probe and host polymer.

Sols composed of Tetraethoxysilane (TEOS) and RTEOS (R: methyl, ethyl, phenyl) catalyzed with HCl were prepared. The molar ratios TEOS :RTEOS:EtOH:H20:HC1 were (1.0-0.8947):(5.26×10−2-0.1579):0.95:1.0:7×10−4, respectively. The sols were analyzed by 29 Si NMR immediately after mixing the reagents in order to study the hydrolysis and condensation reactions. A predominant self-condensation was observed in the TEOS-ETEOS sol, compared to cross-condensation. This result was opposite to the behaviour of the TEOS-MTEOS and TEOS-PTEOS sols.