Alkylene-, arylene- or benzylene-bridged ditin hexachlorides were obtained in high yields from the reaction of the corresponding hexacyclohexylated compounds with tin tetrachloride. These intermediates were successfully transformed into the corresponding alkynides, which gave gels of hybrid materials on hydrolysis. This is the first example of a gel formation from a organometal with the metal fully substituted with covalently-linked organic groups. Subsequent thermal treatment led to mesoporous tin oxide with high surface area and narrow pore size distribution.

We present different arrangments of hybrid nano-objects for optical applications:

- Highly concentrated luminescent colloids (II-VI quantum dots, YVO4:Ln) are prepared and stabilized through the grafting of organic molecules at their surface. These nanocrystals can further be used for the synthesis of well defined nanomaterials. For instance, highly luminescent transparent films for integrated optics are obtained by using YVO4:Ln nanocrystal- silica composites.

- 3D random networks of quantum dots are prepared by gelation of colloids. As in the silica system, the transparent percolating structure can be described as homogeneous assemblies of fractal clusters whose sizes are inferior to visible-range wavelength.

- 3D ordered arrays of quantum dots are prepared by a confined growth of nanocrystals in mesoporous silica films. Using these templates, the 3D ordering of nanoparticles can be extended at a large scale on different substrates. These high density arrangments of nanocrystals are required in different applications such as nonlinear optics or semiconductor lasers.

Biomaterials have made significant contributions to the advancement of modern health care and drug delivery industries. The present research is based on development of porous polymerceramic composite scaffolds using polypropylene (PP) polymer and tricalcium phosphate (TCP) ceramic for bone-graft applications. Three dimensionally interconnected controlled porosity scaffolds were fabricated using a fused deposition modeling (FDM) system. First, ceramic and polymeric materials were compounded under high shear using a torque rheometer. Compounded materials were then extruded to a 1.78mm diameter continuous filament using a single screw extruder. These filaments were used as a feedstock material for an FDM 1650 machine for direct fabrication of controlled porosity parts. Hg-porosimetry was done to determine pore size and their distribution in these structures. Tensile properties of neat composites and as received polymer were measured and compared using standard dog bone samples. Uniaxial compression tests were performed on cylindrical porous samples having average pore size of 160 μm and 36 vol% porosity. These samples showed an average ultimate compressive strength of 12.7 MPa. Average compressive modulus was calculated as 263 MPa. Cytotoxicity and cell proliferation studies were conducted with OPC1 modified human osteoblast cell-line. It was found that composite matrices were non-toxic and they showed excellent cell growth with OPC1 cells.

Inorganic-organic hybrid polymers (ORMOCE®s) combine very good optical and dielectricproperties in the frequency range up to 1 MHz (εr = 3.1 and tanδ = 0.004, both at 1 MHz). Thisis particularly promising for electro-optical (e/o) applications. Multi-layer microwave circuits forhigh frequency applications up to 100 GHz demand extraordinary material properties such as alow permittivity εr < 3 and a dielectric loss tanδ of about 10-3. For low-cost processing, direct UVpatterning would be particularly advantageous. Additionally, the material should be thermallystable at least up to temperatures around 300°C.

We have developed a series of novel ORMOCE® materials for high frequency applications.Using these ORMOCE®s, thick film coatings (up to 150 m) can be produced and directlypatterned by UV lithography with sufficiently high resolution. The synthesis has been carried outusing styrene-substituted organosilanes and silanediols as precursors reacted by simplified solgel-processing in combination with organic cross-linking of polymerizable organic functions.The materials have been characterized at high frequencies up to 40 GHz, exhibiting verypromising dielectric properties of εr = 2.5 and tanδ = 0.0035.

Amino-substituted rare-earth complexes (p-LnNH2DBM and m-LnNH2DBM with Ln3+ = Eu3+, Y3+) are intercalated in the interlayer region of a α-zirconium phosphate lattice to give luminescent hybrid lamellar materials. The preparation of the organic precursors and of the derived organic-inorganic materials is reported. XRD studies show that the hybrid compounds retain a layered structure and FTIR spectroscopy is used to monitor the intercalation reaction. The acid/base interactions between the NH2 functions and the pendant P-OH groups induce an important blue-shift of the absorption maximum of the organic molecule. The Eu3+ luminescence properties are investigated before and after intercalation of the organic complexes in the α-ZrP host structure and the optical characteristics of the para and meta derivatives are also compared.

Laser action is demonstrated in organic/inorganic nanocomposites consisting of pristine and surface-modified ZnO nanoparticles dispersed in an optically inert polymer matrix. The semiconductor particles feature simultaneously gain behavior and strong scattering ability, whereas the polymer matrix provides better processability and mechanical robustness. When excited by a laser pulse of appropriately short duration (pico- to nanoseconds), the composites give off fluorescence emission, which is strongly amplified as a result of light trapping due to multiple scattering. This laser action is manifested as a dramatic increase in the emitted light intensity accompanied by a significant spectral and temporal narrowing above a threshold value of the pumping laser intensity. Applications may include brighter flat-panel displays, inexpensive lasers for communications, military countermeasures, and lasers for search and rescue operations.

A silicon oximide gel was prepared by a reaction in N,N-dimethylformamide between tris(dimethylamino)silylamine (Me2N)3SiNH2 (TDSA) and formamide in a 1:2 molar ratio at 50C. The 29Si, 13C CP-MAS NMR and IR analyses indicated that the gel mainly comprised oximino silicon networks [SiOC(H)=NSi]x. The gel exhibited a microporous structure and had a total surface area of 339 m2/g. A microporous structure with a BET surface area of 195 m2/g was also obtained after pyrolysis of the gel at 1000°C for 2 h. Pyrolysis of the gel under N2 up to 1485°C gave an amorphous silicon oxycarbonitride glass.

The use of an organically modified silica sol-gel matrix containing ligating groups that assist in the formation of metal-oxo clusters is described. The metal-ligand interactions can be tuned by change in external environment such that: a) under overload metal ion concentrations, the sol-gel matrix sequesters the metal ions to promote the growth of 4-7 nm size metal-oxo clusters within the porous structure of the matrix, b) a change in pH releases the metal ions from the bound metal-oxo clusters, thereby making the sol-gel matrix behave as ferritin analogues. These characteristics of the matrix assisted self-assembly of metal-oxo clusters are shown using UVVis, TEM, AES, and EDX data.

Metal-oxide ceramer films have been developed using an acrylic polymer bearing a low amount of methacrylic acid units (ca. 4%mol) as the organic phase with titanium tetrabutoxide as the inorganic sol-gel precursor. The characterisation of free films was realized by various experimental methods. The formation of COOTi bonds prevents large scale phase separation between the organic component and the mineral network. Mechanical properties of the hybrid films have been investigated through dynamic mechanical analysis. The influence of the titania content on the damping peak amplitude suggests that titania is molecularly dispersed in the polymer matrix and that it significantly hinders the segmental motion of the polymer chains. However, the low content in potential carboxylic crosslinking sites explains why the glass transition temperature remains relatively unchanged when titania content increases. Vickers microhardness measurements used in this study allowed us to understand the contribution of the inorganic part (phase TiO2) to the mechanical properties of the polymer. The creep of hybrids has been studied carrying out hardness measurements under various indentation times. The mineral constituent leads to an important increase of the hardness and limits, in a significant way, the creep of polymer.

This paper describes the preparation of hybrid surfactant-templated thin films functionalized with rare-earth (Eu3+ and Tb3+) organic complexes. 2-D hexagonally ordered films are obtained by a one-pot synthesis process based on an acid-catalyzed approach. Ln3+ ions are coordinated to bis-silylated ligands that co-polymerize with TEOS, which enables one to incorporate the fluorescent centers within the silica framework. Luminescent properties of the organic-inorganic mesostructured films are discussed and compared to those of amorphous samples with similar composition.

The evolution of new molecular sieves and associated applications has generated a greater demand for new ways to manipulate and configure nanoporous materials. The required form of a molecular sieve may involve dramatically different length scales, ranging from shaped particles to fibers and continuous coatings. Various examples of these forms based on Dallas Amorphous Materials one (DAM-1), which was synthesized using a water soluble Vitamin E TPGS as the template, will be illustrated. In addition to potential drug delivery applications for this inorganic/organic composite, the hierarchical forms of DAM-1 may be employed in areas ranging from catalysis to sensors. The morphogenesis of DAM-1 shaped particles and its applications in molecular recognition and optical sensing will be described along with a novel process for spinning DAM-1 molecular sieve fibers. Additionally, our patented method for the fabrication of zeolite membranes, using pulsed laser deposition (PLD) will be discussed.

Here we report on the metallization of poly(2-vinylpyridine) (P2VP) by coordination with palladium acetate (PA) followed by reduction with dimethylamine borane (DAB) to metallic palladium. The morphology of the resulting products deposited on a flat surface was analyzed with AFM. If P2VP, PA and DAB are mixed together, the Pd clusters up to 30 nm in diameter are obtained. A two step synthetic procedure was examined. The initially prepared complex P2VPH-1/2(PdCl4) was deposited on Si-wafer and then reduced, leading to the Pd clusters with a narrow size distribution (3 nm height by 100 nm length). Alternately, a step-by-step procedure was used wherein P2VP single molecules were deposited on Si wafers from very dilute acidic aqueous solutions then placed in PA solution and finally reduced with DAB, resulting in the 1.5-5 nm in the diameter wire-shaped Pd nanoparticles with the length of about 350 nm.

Hybrid poly(L-lactic acid)-silica materials for potential use in orthopaedic applications have been prepared by a sol-gel method using an experimental design approach to investigate the effect of synthesis variables separately and together on the physical form of the organic polymer. The five factors investigated were the molar ratios of tetraethyl orthosilicate (TEOS)/Poly(Llactic acid) (PLLA), Toluene/PLLA, EtOH/TEOS, Water/TEOS and HCl (catalyst)/TEOS. All other synthesis conditions were kept constant. X-Ray powder diffraction (Statton's graphical method) and differential scanning calorimetry were used to assess the extent of polymer crystallinity in the hybrid materials. In accordance with other studies, increasing the molar ratio of TEOS/PLLA lead to increasing incorporation of the organic polymer into the silica network. Increase of the toluene/PLLA molar ratio lead to an increase in the crystallinity of the polymer phase. As our studies investigated the effect of synthesis variables simultaneously it was possible to identify, for the first time, that interactions between specific reactants are important in the development of the two structural components of this hybrid system. The most important of these was the TEOS/PLLA*H2O/TEOS interaction that may indicate that silica species from hydrolysed TEOS interact with the PLLA phase possibly via hydrogen bonding and leads to the lowering of the crystalline order of the polymer The results from this study give useful information on the ability of the organic polymer and the silica phase to form interpenetrating networks, an important requirement for the generation of a potential hybrid polyester-silica biomaterial for orthopaedic applications.

Interleaved polystyrene sulfonate polymer between a layered double hydroxide of composition Zn2Al(OH)6Cl. nH2O are prepared either by direct exchange or by in-situ polymerization of the monomer. The latter is confirmed by 13C CP-MAS solid state NMR spectroscopy. This technique provides also clear evidence of the strong interaction between the incorporated monomer and the LDH inorganic framework. A shielding of the aromatic carbon attached to the sulfonate group is observed, this is transmitted through the carbonaceous skeleton to the vinylic carbon. The 2D structure is stabilized with the presence of organic moieties, and even more through the in-situ polymerization process, as exemplified with the conversion from Oh to Td aluminium cations environment. However the difference is diminished with the heating process. The exfoliation/restacking process is found to be here unappropriate, giving rise to ill-defined materials.

Several aluminophosphonate materials have been investigated using both semi-empirical quantum mechanical and Density Functional Theory (DFT) methodologies. The optimised structures obtained are in excellent agreement with experimental results. Important information on the electronic distribution in these structures is obtained, allowing charge distributions to be determined and H2O-framework interactions to be probed. The barriers to rotation for the organic groups in three structures have been investigated. Results for –(CH3) groups in AlMePO-α and AlMePO-β, yield barrier heights that are consistent with rapid rotation at ambient temperature, whereas the barrier height obtained for –(C6H5) in AlBzPO-I suggests that the framework will significantly hinder rotation. The use of modelling to help elucidate the structure of a novel compound, AlMePO-2, and to probe the structure and stability of a hypothetical aluminium ethyl phosphonate, AlEtPO, are also illustrated.