Poly(ethylene oxide)—poly(propylene oxide)—poly(ethylene oxide) (PEO-PPO-PEO) was reacted with iron ethoxide in a molar ratio of 1:2. This modified surfactant was used as a template for the synthesis of mesostructured, nanocomposite iron oxide-silica films and powders. Grazing incidence (GI)-SAXS measurements of the films showed that depending on the concentration of the surfactant wormhole-like, 2d-centered rectangular, orthorhombic and lamellar nanocomposite structures were formed. Interestingly, the mesoscopic ordering of the orthorhombic and 2d-centered rectangular pore structure is retained even after calcination at 1000 °C for one hour. The influence of heat treatment on the mesostructure was investigated by GI-SAXS, TEM and N2-sorption measurements.

Aging of silica gels before drying is known to result in significant changes in xerogel morphology, porosity and properties. In this study, the influence of aging gels on the porosity and morphology of alkylene-bridged polysilsesquioxane xerogels was examined. Gels of hexylene-, heptylene, octylene, nonylene, and decylene-bridged polysilsesquioxanes were prepared by the sol-gel polymerization of the respective bis(trimethoxysilyl)alkane monomers under acidic or basic conditions in methanol and in tetrahydrofuran. The gels were aged 3, 7, 14, 28, 35, 42, 49, and 56 days before drying to afford xerogels. The xerogels were characterized by nitrogen sorption porosimetry. Xerogels prepared in THF were non-porous. Those prepared and aged under basic conditions in methanol or tetrahydrofuran exhibited coarsening of porosity with aging time. With the exception of the hexylene-bridged gels, those prepared and aged in acidic methanol showed little change with aging. The surface area of the hexylene-bridged xerogels nearly tripled with aging times of up to several weeks, then decreased, for the gels aged for more than two weeks, to around 100 meters squared per gram.

Composites of low density polyethylene (LDPE) and 40 wt% Mg(OH)2 modified with several kinds of polysiloxane oils were prepared in order to evaluate the effect of the surface modification of Mg(OH)2 on the mechanical properties and oxygen index of the composites. A composite containing Mg(OH)2 modified with methylhydrogen polysiloxane oil showed an oxygen index of 23.8% O2 and an elongation of 425%. These values were superior to other composites containing Mg(OH)2 modified with other kinds of polysiloxane oils. The oxygen index could be enhanced up to 24.8% by co-addition of 5 wt% fumed silica as another flame retardant to the composite of LDPE and 35 wt% Mg(OH)2 (modified with methylhydrogen polysiloxane oil), while fixing the total amount of the flame retardants at 40 wt%.

Two general microemulsion-based routes towards surface-functionalized metal oxide nanoparticles serving as macroinitiators in “grafting from” atom transfer radical polymerization (ATRP), are presented. Metal alkoxides modified with several β-diketone derivatives carrying potential ATRP-initiating sites served as precursors for the particle formation leading in an solgel process to in situ-functionalized titanium-, zirconium-, tantalum-, vanadium-, yttrium-, and iron oxide nanoparticles. The obtained systems were compared with metal oxide nanoparticles prepared by using metal salts as precursors which were functionalized in a second step with ATRP-initiator containing silane coupling agents. The obtained particles had diameters between 5 nm and 640 nm and served as multifunctional polymerization initiators in ATRP using styrene and methyl methacrylate as monomers.

Hybrid organic/inorganic nanocomposites composed of zinc hydroxide and surfactant molecule, and/or zinc oxide nanoparticles were fabricated using pulsed laser ablation of zinc in aqueous solutions of various surfactants. A Zn plate was ablated by a pulsed Nd:YAG laser in four types of surfactant solutions with different concentrations. Zinc oxide nanoparticles with average diameter of 10–40 nm were obtained in cationic, amphoteric and nonionic surfactant solutions. Unique layered organic/inorganic nanocomposites composed of zinc hydroxide layers and surfactant molecules were obtained in aqueous solutions of the anionic surfactants, sodium alkyl sulfate (CnH2n+1SO4-·Na+). The carbon number, n, in the alkyl sulfate family is very important for the formation and structure of the layered nanocomposites. The layered organic/inorganic nanocomposite can be obtained only in the specific sodium alkyl sulfates (n = 12, 13, 14 and 16) and the layer spacing of the nanocomposites increased with n from 26.8 Å to 42.0 Å. It is shown that the structures of ZnO nanoparticles and layered organic/inorganic nanocomposites can be controlled by the type of surfactants in solution.

Porous SiO2-PDMS-TiO2 hybrid materials have been prepared by the Sol-Gel method using tetraethoxysilane (TEOS), silanol terminated-Polydimethylsiloxane (PDMS) and tetrabuthylortotitanate (TBT) as precursors. These materials were characterized by means of nitrogen adsorption, mercury porosimetry and helium picnometry. It was found that the meso and microporosity are predominant in all samples. The influence of the TBT concentration in the final pore structure and texture of SiO2-PDMS-TiO2 hybrid materials was studied. Results showed that increasing the TBT concentration decreases the pore volume of micropores, mesopores and macropores. On the other hand the specific surface areas of meso and macropores decreases with increasing TBT content, but micropore areas increase with TBT. These results are assigned to the formation of ultramicropores when TBT is added. In addition, surface roughness is found to increase with TBT concentration which is attributed to the formation of hydrous titanium oxide based nanoparticles.

The synthesis of vanadium oxide nanotubes containing phosphorus (VPOx-NT) is described. A mixture of V2O5.nH2O gels, phosphoric acid and hexadecylamine was heated under hydrothermal conditions at 180°C for 7 days. The VPOx nanotubes were characterized by X-ray diffraction, scanning and transmission electron microscopy, 51V and 31P solid state NMR. In-situ experiments were performed in order to get a better understanding of the mechanism of these nanotubes formation.

A ceramic-powder polymer composite, making use of a newly developed ceramics - CaCu3Ti4O12 (CCTO) - that has a giant dielectric constant as the filler, is developed. In this work, poly(vinylidene fluoride - trifluoroethylene) [P(VDF-TrFE)] 55/45 mol% copolymer was used as matrix. It is found that the wettability between the copolymer and CCTO is poor, which makes the solution cast composites have a poor uniformity. The uniformity and thus the dielectric constant of the composites can be significantly improved by using hot-press technology to form “sandwich” structure. It is also found that the thermal annealing process can improve the dielectric constant of the composite. The experimental data show that for the flexible composites the dielectric constant at 1 kHz can reach more than 300 at room temperature and more than 700 at ∼70 °C.

The introduction of organic substituents into sol-gel materials can often result in networks that collapse during drying to afford non-porous xerogels. This can prove useful if non-porous coatings or membranes are the ultimate objectives. Collapse of porosity is also manifested in bridged polysilsesquioxanes with flexible bridging groups. Alkylene-bridged polysilsesquioxanes are hybrid xerogels whose organic bridging group is an integral constituent of the network polymer that can be systematically varied to probe the influence of its length on the xerogels' porosity and morphology. Our previous studies have shown that hexylene-bridged polysilsesquioxane xerogels prepared from 1, 6-bis(triethoxysilyl)hexane under acidic conditions are nonporous while the pentylene-bridged polysilsesquioxanes prepared under the same conditions are porous. We also discovered that the more reactive 1, 6-bis(trimethoxysilyl)hexane monomer could polymerize under acidic conditions to afford porous xerogels. Here, we have extended our study of bis(trimethoxysilyl)alkanes to include the heptylene (C7), octylene (C8), nonylene(C9) and decylene (C10) bridges so as to ascertain at what bridging group length the porosity collapses. The morphology of the resulting xerogels was characterized by nitrogen sorption porosimetry and electron microscopy. Solid state NMR was used to structurally characterize the materials.

A novel epoxy-functionalised sol-gel material system for use in photonic waveguiding applications has been developed for use in short-range optical interconnect applications. The sol-gel material is deposited by spin coating to form a thin-film up to 25μm in thickness. The resulting film is selectively cross-linked using photo-lithography, as part of a UV-thermal curing process. A tunable film refractive index over the range 1.48–1.515 is demonstrated. The near-field images of transmitted radiation (633nm) from fabricated waveguide structures shows both waveguiding and efficient light confinement within the UV-thermally produced core regions. A thermal stability analysis of the waveguides following “Telcordia” environmental testing protocols for passive devices is presented. It is concluded that this materials system has the potential for use in waveguiding applications in environments where enhanced thermo-mechanical stability is required.

Hybrid membranes containing Nafion and phosphosilicate gels were prepared using infiltration and recasting methods. The hybrid membranes were investigated using complex impedance spectroscopy. Conductivities were determined as a function of relative humidity. Infiltrated membranes, which contained gel in more or less discrete particles, were compared with recast membranes where the gel was more evenly distributed. Both of the modified membranes were compared to unmodified Nafion. The impedance spectra were analyzed to distinguish electrode interface effects from bulk transport phenomena.

Polysilane/inorganic (silica, titania) nano-hybrids might be attractive materials for organic photonics. Polymethylphenylsilane (PMPS)/silica nano-hybrid thin films were prepared by a sol-gel reaction of PMPS block copolymers with alkoxysilanes. The refractive index of hybrid thin films could be controlled with the composition ratio of PMPS, and the value was changed by UV irradiation accompanying photodecomposition of PMPS. After development of the irradiated hybrid thin films, nano porous (ca. 20nm) silica thin films were generated by removing the decomposed PMPS segments and a high refractive index difference occurred between irradiated and non-irradiated part in the hybrid thin films. Furthermore, under photodecomposition of polysilane copolymers, polysilane functioned as a reducing agent of gold (III) ions to prepare the gold nanoparticles.

Complete delamination of clay in polymer matrix has been strongly prohibited due to strong adhesion of guest polymer chains between hydrophilic clay as well as degradation and desorption of organic materials in the gallery at high temperature. Incorporation of charged nanosized polystyrene beads directly into the gallery of pristine clay through exfoliation-exchange mechanism has been proposed to overcome the drawbacks.

Synthesis of polymer nanobeads via emulsifier-free emulsion polymerization allowed to achieving formation of particles of appropriate particle size and surface charge density. Surface characterization, performed with XPS and ToF SIMS, has provided the results on the existence and the nature of the functional groups on the polymer particle surface, which have been found to be in a good compliance.

Morphology of polymer-incorporated clay was observed from TEM, FE-SEM images. Study on mechanism of incorporation via XRD, XPS, ToF-SIMS suggested that adsorption of polymer nanobeads through cationic exchange of intergallery cation of clay for onium ion at the surface of polymer nanobead not only improves compatibility of clay with polymer matrix, but, what is essential, dramatically promotes expansion of clay gallery.

The geometrical properties of co-continuous macroporous silica monoliths have been studied by laser scanning confocal microscopy (LSCM) and a comparison with mercury intrusion method has been made. From three-dimensional images obtained by LSCM observation, probability density distributions of curvatures have been calculated on gel skeleton surface by the “sectioning and fitting method”. Measured liquid transport behavior in macroporous siloxane gels has been related to the obtained curvature distributions.

In this work, we report a new intercalation reaction: three different n-alkylamines (n-butylamine, n-hexylamine and n-octylamine), in vapor phase, were intercalated into non-dispersed vanadium pentoxide xerogel and into this lamellar material homogeneously dispersed in Si–O–Si network (obtained by polycondensation of the silicon alkoxide) interpenetrated with V–O–V and V–OH–V polymeric chains. The reaction with non-dispersed xerogel leads to increase of interlamelar distance for low time of reaction (up to 2 hours) and after 24 hours we observed a new phase. In contrast, for the reaction with xerogel dispersed in silica, it was observed only the increase of the basal distance retaining the original bi-dimensional structure (00l diffractions lines were observed); suggesting that the silica matrix stabilizes the vanadium pentoxide structure as the result of a mutual “solubility” due to cross-linking and entanglement of both components. In addition, for this reaction it was observed a selective amine intercalation. The reactions were monitored using powder X-ray diffraction, Fourier-transform infrared and electronic spectroscopy, electron paramagnetic resonance and scanning electron microscopy.

The objective of this paper is to review various solid state NMR techniques that have been, or can be used for the structural characterization of siloxane—oxide hybrid systems prepared by sol-gel process, and to discuss the type of information they provide, as well as their limitations. More precisely, this paper focuses on NMR techniques to probe and quantify the different types of oxo-bridges (M–O–M of oxide network, Si–O–Si of siloxane chains and Si–O–M siloxane–MxOy interface) in siloxane-oxide nanocomposites prepared through hydrolysis and condensation of organosilanes and M(OR)n alkoxides. In addition the influence of the functionality of the silicon alkoxides and the nature of the MxOy oxides on the extent of the Si-O-M interface will be examined.

Highly porous inorganic-organic hybrid monoliths with mesopores in a macroporous network have been prepared from methyltris(2-hydroxyethoxy)silane (MeGMS) and tetrakis(2-hydroxyethoxy)silane (EGMS) in the presence of an amphiphilic block copolymer. The amount of methyltris(2-hydroxyethoxy)silane (MeGMS) in the gel has been varied from 0 to 100 %. These glycol-modified silanes have the advantage of being water-soluble and thus allowing for a direct templating of liquid-crystalline surfactant mesophases without the presence of a homogenizing organic solvent such as ethanol. The wet gels have been dried by supercritical extraction with carbon dioxide.

In the present work, the sol-gel behaviour of these glycol-modified silanes is discussed especially with a focus on the formation of the meso- and macrostructure. In addition, the influences of the varying ratios of methyltris(2-hydroxyethoxy)silane on the structural features of the gels are investigated by various analytical techniques such as small angle X-ray scattering, nitrogen sorption, and scanning electron microscopy.

Organic/MoO3 nanohybrid thin films have been successfully prepared by an ex-situ intercalation process. The host MoO3 films were first deposited on LaAlO3 (LAO) single crystal substrates by using a CVD method followed by the intercalation of butylammonium ions, (BuNH3)+, into the MoO3 films to give (BuNH3)xMoO3 thin films. The preparation of highly b-axis oriented MoO3 films is crucial to prepare the (BuNH3)xMoO3 films. The (BuNH3)xMoO3 thin films exhibit a resistance-increasing response to aldehyde gases as in the case of bulk samples, whereas no response was observed for methanol, ethanol, chloroform, acetone, toluene, and xylene. The thin film process developed for intercalative organic-inorganic hybrid makes it possible to apply this material in VOC sensor devices.

Titania particles (P25 DEGUSSA AG) were treated by a solution of 12-mercaptododecyl-phosphonic acid (MDPA) in toluene to obtain an organic-inorganic hybrid material with thiol functions at the surface. This material was characterized by chemical analysis, solid state 31P MAS NMR and FTIR spectroscopies, and XPS. Reaction of the phosphonic acid end of MDPA with the TiO2 surface led to the formation of a relatively dense and well-ordered self-assembled monolayer (SAM), with a density of about 3.9 SH functions per nm2. This material was tested for the extraction of mercury in water at pH 7, 9, and 11. Chemical analysis indicated no loss of SH functionality, even at pH 11. The best extraction results were obtained at pH 9 and 11, with a metal extraction ability between 85 and 90%.

Incorporation and subsequent stabilization of organic molecules into layered double hydroxide are investigated. Through two types of hybrid materials, organic dyes and aniline-based monomers interleaved between LDH materials of cation composition Zn2Al and Cu2Cr respectively, it is shown that the effect of the constrainment is revealed by the interactions different according to the molecule size and stacking as exemplified by dye molecules, orange 6 and green 25 acids and two aniline-based monomers, m-amino-4-benzenesulfonic and 3-aniline-1-propanesulfonic acids.