Structural investigation of alumina silica mixed oxide gels prepared from organically modified precursors

Peterlik, Herwig; Rennhofer, Harald; Torma, Viktória; Bauer, Ulrike; Puchberger, Michael; Hüsing, Nicola; Bernstorff, Sigrid; Schubert, Ulrich

doi:10.1016/j.jnoncrysol.2007.01.016

Cited by 17 publications

(13 citation statements)

References 16 publications

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“…The possibility of incorporating organic rich functional groups in the mesostructure of inorganic silica to produce organic/inorganic hybrids has attracted the attention of several researchers for a wide variety of applications (Yano et al, 1998;Itagaki et al, 2003;Zhao et al, 1998;Nakane et al, 1999;Bandyopadhyay et al, 2005;Tamaki & Chujo, 1998;Posset et al, 2004;Jitianu et al, 2003;Peterlik et al, 2007). In a typical process, a chemically functional group is introduced by a 3-functional alkoxide, while the gel backbone is formed by siloxane bonds characteristic of the silica structure, which give mechanical stability for the functionalized material (Itagaki et al, 2003;Zhao et al, 1998;.…”

Section: Introductionmentioning

confidence: 99%

“…In a typical process, a chemically functional group is introduced by a 3-functional alkoxide, while the gel backbone is formed by siloxane bonds characteristic of the silica structure, which give mechanical stability for the functionalized material (Itagaki et al, 2003;Zhao et al, 1998;. Hybrid gels have attracted attention in the domain of heterogeneous catalysis, where the organic moiety of the trialkoxysilane has been used to make a complex with a catalytically active metal ion (Peterlik et al, 2007), and for a variety of optical (Jitianu et al, 2003) and biological applications. The synthesis and characterization of organic/inorganic hybrids aim also to improve the properties of silica gels with respect to their fragility, brittleness and moisture sensitivity, which limit their application in several fields.…”

Section: Introductionmentioning

confidence: 99%

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Structure and aggregation kinetics of vinyltriethoxysilane-derived organic/silica hybrids

et al. 2010

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The aggregation kinetics of solutions of vinyltriethoxysilane‐derived organic/silica hybrid species were studied by small‐angle X‐ray scattering (SAXS) in a strongly basic medium. The SAXS intensity was analysed by a modified Sharp–Bloomfield (SB) global function and its evolution was found to be compatible with the growth, coiling and branching of the polymeric macromolecules in solution. A form factor valid for randomly and nonrandomly branched polycondensates and for polydisperse coils of linear chains was used in the modified SB model, instead of the Debye function valid for monodisperse coils of linear chains. The aggregation kinetics are accelerated with increasing base concentration in the studied range, but all the kinetics curves can be matched to a unique curve using an appropriate time scaling factor. The aggregation kinetics suggest that physical forces (hydrothermal forces) associated with phase coarsening could be active in the aggregation process, together with diffusion mechanisms.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Structure and aggregation kinetics of vinyltriethoxysilane-derived organic/silica hybrids

et al. 2010

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“…Clusters are 16 . This calculation also explains why two zirconium atoms in Ti 2 Zr 6 O 6 (OMc) 20 polyhedra were inserted in the Ti 2 Zr 6 O 6 (OMc) 20 cluster core, the composition of the resulting cluster would be Ti 2 Zr 8 O 8 X 24 . The mono-anionic ligands X must then occupy 52 coordination sites (for 8-coordinate Zr).…”

Section: Mixed-metal Oxo Clustersmentioning

confidence: 78%

“…SAXS investigations through all preparation stages, i.e., hydrolysis of M(OR) x (OTH), gelation, aging and drying, resulted in a clear picture on the structure evolution [19,20]. Small MO x particles (clusters) are formed immediately after addition of water.…”

Section: A New Type Of Single-source Precursorsmentioning

confidence: 99%

Heterobimetallic sol–gel precursors and intermediates

Schubert

2015

J Sol-Gel Sci Technol

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The question how the metals in bimetallic solgel materials are positioned relative to each other and how the dispersion of the metals can be controlled is a major preparative and analytical challenge. Two particular aspects are addressed: The first is an alternative type of single-source precursors where the two metals are interlinked through an organic spacer. The new options provided by this approach are demonstrated for metal oxide/ silica nanocomposites, zinc titanate and Co 3 O 4 /ceria catalysts. The second issue with regard to heterobimetallic systems is the kind of intermediates formed during sol-gel co-processing of two different metal precursors (metal alkoxides or metal alkoxide ? metal salt). Systematic investigation of the structures of Ti/M oxo clusters (M = main group or transition metal, or lanthanide) shows some interesting common construction principles and thus sheds light on early stages of the structural evolution in mixed-metal oxide systems. Graphical abstract

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“…Silica-based mixed-metal oxides are mostly prepared by route 1 because of the availability of a variety of alkoxysilanes (RO) 3 Si(CH 2 ) 3 X, in which X is a coordinating group (such as an amino 2 or β-diketonate group 3 ). When (RO) 3 Si(CH 2 ) 3 X is treated with metal ions or metal alkoxide moieties (M), a bimetallic precursor [(RO) 3 Si(CH 2 ) 3 X] n M is formed.…”

Section: Introductionmentioning

confidence: 99%

Zinc(II) Complexes with Dangling Functional Organic Groups

et al. 2012

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Zinc(II) complexes with dangling functional organic groups were synthesized by reaction of zinc acetate with a series of bifunctional p-substituted benzene derivatives (a combination of carboxylate, oximate, amino, β-ketoimine, and salicylaldime groups). Selective coordination to carboxylate groups was observed when the second functional group was an oxime or β-ketoimine group. When the second group was an amine or salicylaldimine moiety, these groups were additionally coordinated. From the reaction with p-aminobenzoic acid, the compound [Zn2(OOCCH3)(OOC–C6H4–NH2)3]∞ was crystallized. It is a three-dimensional coordination polymer with bridging aminobenzoate ligands.

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Structural investigation of alumina silica mixed oxide gels prepared from organically modified precursors

Cited by 17 publications

References 16 publications

Structure and aggregation kinetics of vinyltriethoxysilane-derived organic/silica hybrids

Structure and aggregation kinetics of vinyltriethoxysilane-derived organic/silica hybrids

Heterobimetallic sol–gel precursors and intermediates

Zinc(II) Complexes with Dangling Functional Organic Groups

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