The formation and design of a hierarchically nanostructured poly(isobutylene)-based ionic liquid (PIB-ILs) is reported, displaying assembly into classical multiplets and an additional ordering of the aromatic counteranions. Three PIB-ILs (Mn = 3600 and 8600 g mol(-1) ), bearing imidazolium (1a), N-methylpyrrolidinium (1b), and triethylammonium cations (1c) together with the aromatic 2-(methylthio)benzoate anion are prepared via a combination of living carbocationic polymerization, "click" reactions and subsequent anion metathesis. The morphology of the novel PIB-ILs as well as its temperature-dependent behavior has been studied via small angle X-ray scattering, displaying two different transition temperatures: one originating from ordering of micelles within a cylinder, and the second from cylinder-cylinder arrangement.
View Article and Find Full Text PDFCo3 O4 -modified CeO2 (Co/Ce 1:4) was prepared by a combination of sol-gel processing and solvothermal treatment. The distribution of Co was controlled by means of the synthesis protocol to yield three different morphologies, namely, Co3 O4 nanoparticles located on the surface of CeO2 particles, coexistent Co3 O4 and CeO2 nanoparticles, or Co oxide structures homogeneously distributed within CeO2 . The effect of the different morphologies on the properties of Co3 O4 -CeO2 was investigated with regard to the crystallite phase(s), particle size, surface area, and catalytic activity for CO oxidation.
View Article and Find Full Text PDFHierarchically organized silica-titania monoliths were synthesized under purely aqueous conditions by applying a new ethylene glycol-modified single-source precursor, such as 3-[3-{tris(2-hydroxyethoxy)silyl}propyl]acetylacetone coordinated to a titanium center. The influence of the silicon- and titanium-containing single-source precursor, the novel glycolated organofunctional silane, and the addition of tetrakis(2-hydroxyethyl)orthosilicate on the formation of the final porous network was investigated by SEM, TEM, nitrogen sorption, and SAXS/WAXS. In situ SAXS measurements were performed to obtain insight into the development of the mesoporous network during sol-gel transition.
View Article and Find Full Text PDFCompound [Ni(AEAPTS)2]3[Fe(CN)6]2 (AEAPTS = N-(2-aminoethyl)-3-aminopropyltrimethoxysilane), in which Ni(2+) and Fe(3+) ions are ferromagnetically coupled through cyano bridges, was prepared. Sol-gel processing of the AEAPTS derivative resulted in incorporation of the cyanometallate in silica. The obtained material is magnetically ordered below 22 K with an effective magnetic moment μeff of 4.
View Article and Find Full Text PDFTo investigate the original and promising luminescence properties of ionic nanoparticle networks (INN), various material compositions were investigated. In this work, the linker used to network the silica nanoparticles was varied; numerous substituted or non-substituted imidazolium, pyrazolium and pyridinium linkers are presented. Photoluminescence experiments on the INN hybrid materials revealed strong emission bands over a broad range in the visible region of the light spectrum.
View Article and Find Full Text PDFReaction of Ti(OiPr)4 with several tri- and tetracarboxylic acids, followed by hydrolysis, resulted in microporous, structured materials, with microporous surface areas up to 340 m(2) g(-1). Depending on the kind of carboxylic acid, the Ti : COOH ratio and the Ti : H2O ratio, either pillared layered or surface fractal 3D structures were obtained according to SAXS measurements. The most pronounced layered structure was found for 1,2,4,5-benzenetetrabenzoic acid and a Ti : H2O ratio of 4, while a Ti : H2O ratio of 2 resulted in a 3D structure.
View Article and Find Full Text PDFHighly dispersible MoS2 nanoparticles have been prepared via surface-modification using a novel tetraethylene glycol-based ionic liquid containing a chelating moiety attached to the cation. The choice of the respective ligand enables the generation of highly dispersible MoS2 nanoparticles with either polar, hydrophobic or "amphiphilic" surfaces, forming highly stable dispersions or microemulsions.
View Article and Find Full Text PDFIn this work Imidazolium Nanoparticle Networks (INNs) with chloride counter-ions were used to complex copper dichloride. This complexation reaction leads to the formation of a green material. The properties of the copper INN material were compared to: first, copper imidazolium complexes, without the presence of silica nanoparticles, which are not thermochromic; second, chloride-containing INN material.
View Article and Find Full Text PDFEuropium(III) ions containing mesoporous silica coatings have been prepared via a solvent evaporation-induced self-assembly (EISA) approach of different single-source precursors (SSPs) in the presence of Pluronic P123 as a structure-directing agent, using the spin-coating process. A deliberate tailoring of the chemical composition of the porous coatings with various Si:Eu ratios was achieved by processing mixtures of tetraethylorthosilicate (TEOS) and Eu(3+)-coordinated SSPs. Small-angle X-ray scattering (SAXS) and transmission electron microscopy (TEM) analyses demonstrate that the thin metal oxide-doped silica coatings consist of a porous network with a short-range order of the pore structure, even at high europium(III) loadings.
View Article and Find Full Text PDFWe report an ionic hybrid based on silica nanoparticles as the anion and amine-terminated poly(ethylene oxide) (PEO) as a cation. The charge on the nanoparticle anion is carried by the surface hydroxyls. SAXS and TEM reveal an exceptional degree of dispersion of the silica in the polymer and high degree of order in both thin film and bulk forms.
View Article and Find Full Text PDFHybrid, hierarchically organized, monolithic silica gels, comprising periodically arranged mesopores and a cellular macroscopic network, have been prepared through a co-condensation reaction of tetrakis(2-hydroxyethyl)orthosilicate with chloromethyl-trimethoxysilane or 3-(chloropropyl)-triethoxysilane. Subsequent conversion of the chloro groups into azido groups, by nucleophilic substitution with NaN(3) in N,N-dimethylformamide, was conducted upon preservation of the monolithic structure. However, treatment with NaN(3) had a strong influence on the structure in the mesoporous regime, with changes such as an increase of mesopore diameter, pore volume and lattice constants, as well as a concomitant decrease of the pore wall thickness, as confirmed by small angle X-ray scattering, transmission electron microscopy, and nitrogen sorption analysis.
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