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  • 1
    Electronic Resource
    Electronic Resource
    Structure and Properties of Silica Derived from Silicon Alkoxide Reacted with Tartaric Acid (1997)
    Westerville, Ohio : American Ceramics Society
    Journal of the American Ceramic Society 80 (1997), S. 0 
    Details
    ISSN: 1551-2916
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: The effects of tartaric acid that was used in sol–gel processing on specific surface area, pore-size distribution, and gel structure of sol–gel-derived silica gels were investigated. The specific surface area of silicas that were calcined at 450°C increased from ∼600 m2/g to ∼1200 m2/g as the amount of tartaric acid that was used increased. The pore-size distribution changed as the surface area increased, and only the gels that had a surface area of 930-990 m2/g showed a very sharp pore-size distribution in the mesopore range. The difference in gel structure and properties was explained in terms of the acidity of tartaric acid and the inhibition of condensation among primary particles through the coordination or adsorption of tartaric acid on the particle surface. From the thermal behavior of the gels with different features, it was concluded that gel properties are determined not only by the structure of the precursor gel but also by the surface activity. The gel with uniform mesopores gave a high surface area over a wide range of calcination temperatures.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1151-2916.1997.tb03160.x
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  • 2
    Electronic Resource
    Electronic Resource
    Organozeolite materials and their properties (1999)
    Springer
    Catalysis surveys from Japan 3 (1999), S. 119-126 
    Details
    ISSN: 1572-8803
    Keywords: organozeolite ; microporous and mesoporous material ; inorganic-organic composite ; synthesis ; phosphonate ; aluminomethylphosphonate
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Attempts in developing organozeolites, namely microporous and mesoporous crystalline inorganic-organic composites with a zeolite-like three-dimensional framework and organic moieties covalently connected to the framework, are briefly reviewed. MCM-41 type mesoporous materials modified by organic functional groups have been prepared by use of organosiloxane as a part of Si sources and by post-modification of the purely inorganic materials using organosiloxane. Also, the incorporation of organic moieties into the zeolite frameworks has been tried. Recently, several novel metal organophosphonates with a three-dimensional framework, which can be regarded as organozeolites, have been prepared. Along with these new attempts, the authors' studies in preparation, structural analysis and gas adsorption properties of microporous aluminomethylphosphonates are introduced.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1019023702312
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  • 3
    Electronic Resource
    Electronic Resource
    Selective Formation of Spinel Iron Oxide in Thin Films by Complexing Agent-Assisted Sol-Gel Processing (1997)
    Springer
    Journal of sol gel science and technology 8 (1997), S. 77-81 
    Details
    ISSN: 1573-4846
    Keywords: iron oxide ; structural control ; complexing agent ; thin film ; sol-gel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The structure of iron oxide was controlled by regulating the hydrolytic polymerization of aquo iron complexes with organic polydentate ligands such as diols. Iron oxides were prepared by calcining the precursor polymers obtained from iron nitrate nonahydrate and diols. When the diols were 1,2-pentanediol, 1,2-hexanediol and 1,2-octanediol, α -Fe2O3 with corundum structure appeared exclusively or as the main crystalline phase, in spite of the amount of diol used and the calcination temperature. In the case of 1,2-decanediol and 1,2-dodecanediol, when five moles of the diols were used to one mole of iron nitrate and the calcination temperatures were below 400° C, γ -Fe2O3 with spinel structure appeared as the main phase and, when less than five moles of the diols were used, α -Fe2O3 appeared exclusively or as the main phase, irrespective of the calcination temperature. This tendency was also observed in thin films. Thus, a transparent magnetic film composed of γ -Fe2O3 could be prepared by applying a benzene solution of the iron polymer, obtained with 5 equivalents of 1,2-decanediol, on quartz and calcining the gel film at 350° C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026407306265
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  • 4
    Electronic Resource
    Electronic Resource
    Effect of Organic Ligands Used in Sol-Gel Process on the Formation of Mullite (1997)
    Springer
    Journal of sol gel science and technology 8 (1997), S. 101-106 
    Details
    ISSN: 1573-4846
    Keywords: mullite ; organic ligand ; hydrolytic polymerization ; sol-gel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The preparation of mullite by the sol-gel method using organic polydentate ligands and the effect of the raw materials and organic polydentate ligands on the formation of mullite were investigated. Two series of samples were prepared using tetraethoxyorthosilicate (TEOS) and aluminum nitrate nonahydrate, or dibutoxyethylacetoacetatoaluminum (Al(OBu)2(AcAcEt)) as the silica and alumina sources, respectively, and using ethylene glycol (EG), 1,3-propanediol (PD), 1,3-butanediol (BD), 2-methyl-2, 4-pentanediol (MPD), diethlene glycol monoethyl ether (DEME) and ethoxyethanol as the ligands. When the alumina source was aluminum nitrate nonahydrate, mullite was apt to appear in the order of EG 〉 PD 〉 MPD. When Al(OBu)2(AcAcEt) was the alumina source, the tendency toward the appearance of mullite crystalline phase was EG 〉 BD 〉 DEME 〉 MPD. Between the two alumina sources, aluminum nitrate nonahydrate gave mullite much easier than Al(OBu)2(AcAcEt). These relationships were discussed from the viewpoints of the coordination ability of the ligands and the miscibility between the silica and alumina.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1026467608991
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  • 5
    Electronic Resource
    Electronic Resource
    Selective formation of spinel iron oxide in thin films by complexing agent-assisted sol-gel processing (1997)
    Springer
    Journal of sol gel science and technology 8 (1997), S. 77-81 
    Details
    ISSN: 1573-4846
    Keywords: iron oxide ; structural control ; complexing agent ; thin film ; sol-gel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The structure of iron oxide was controlled by regulating the hydrolytic polymerization of aquo iron complexes with organic polydentate ligands such as diols. Iron oxides were prepared by calcining the precursor polymers obtained from iron nitrate nonahydrate and diols. When the diols were 1,2-pentanediol, 1,2-hexanediol and 1,2-octanediol, α-Fe2O3 with corundum structure appeared exclusively or as the main crystalline phase, in spite of the amount of diol used and the calcination temperature. In the case of 1,2-decanediol and 1,2-dodecanediol, when five moles of the diols were used to one mole of iron nitrate and the calcination temperatures were below 400°C, ψ-Fe2O3 with spinel structure appeared as the main phase and, when less than five moles of the diols were used, α-Fe2O3 appeared exclusively or as the main phase, irrespective of the calcination temperature. This tendency was also observed in thin films. Thus, a transparent magnetic film composed of γ-Fe2O3 could be prepared by applying a benzene solution of the iron polymer, obtained with 5 equivalents of 1,2-decanediol, on quartz and calcining the gel film at 350°C.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02436821
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  • 6
    Electronic Resource
    Electronic Resource
    Effect of organic ligands used in sol-gel process on the formation of mullite (1997)
    Springer
    Journal of sol gel science and technology 8 (1997), S. 101-106 
    Details
    ISSN: 1573-4846
    Keywords: mullite ; organic ligand ; hydrolytic polymerization ; sol-gel
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The preparation of mullite by the sol-gel method using organic polydentate ligands and the effect of the raw materials and organic polydentate ligands on the formation of mullite were investigated. Two series of samples were prepared using tetraethoxyorthosilicate (TEOS) and aluminum nitrate nonahydrate, or dibutoxyethylacetoacetatoaluminum (Al(OBu)2(AcAcEt)) as the silica and alumina sources, respectively, and using ethylene glycol (EG), 1,3-propanediol (PD), 1,3-butanediol (BD), 2-methyl-2, 4-pentanediol (MPD), diethlene glycol monoethyl ether (DEME) and ethoxyethanol as the ligands. When the alumina source was aluminum nitrate nonahydrate, mullite was apt to appear in the order of EG〉PD〉MPD. When Al(OBu)2(AcAcEt) was the alumina source, the tendency toward the appearance of mullite crystalline phase was EG〉BD〉DEME〉MPD. Between the two alumina sources, aluminum nitrate nonahydrate gave mullite much easier than Al(OBu)2(AcAcEt). These relationships were discussed from the viewpoints of the coordination ability of the ligands and the miscibility between the silica and alumina.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02436825
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  • 7
    Electronic Resource
    Electronic Resource
    Chemical modification of silicone elastomers for optics (1990)
    Springer
    Journal of materials science 25 (1990), S. 3368-3374 
    Details
    ISSN: 1573-4803
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract Polysiloxanes with Si-H groups were chemically modified using vinyl compounds with phenyl, naphthyl, anthryl, andn-perfluorooctyl side groups by platinum catalysis (hydrosilylation). The introduction of aromatic groups increased the refractive index of poly(dimethyl siloxane) (n=1.403) up ton=1.70 depending on the degree of substitution and the kind of aromatic groups. Similarly, then-perfluorooctyl group reduced the refractive index to 1.35. Therefore, the chemical modification enabled us to obtain polysiloxanes with refractive indices between 1.35 and 1.70. The modifications affected the glass-transition temperature of polysiloxanes, and the effects were analysed. The modified polysiloxanes may be of use in fabrication of very flexible optical fibres for purposes such as sensors, image guides, data links and optical fibres for communications over very short distances.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00587699
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  • 8
    Electronic Resource
    Electronic Resource
    Transformation of intercalated layered silicates to zeolites in the solid state (1996)
    Weinheim : Wiley-Blackwell
    Advanced Materials 8 (1996), S. 759-762 
    Details
    ISSN: 0935-9648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 6 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/adma.19960080913
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  • 9
    Electronic Resource
    Electronic Resource
    Immobilization of catalase by polyion complex (1991)
    New York, NY [u.a.] : Wiley-Blackwell
    Journal of Applied Polymer Science 43 (1991), S. 2219-2222 
    Details
    ISSN: 0021-8995
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Catalase was immobilized in a polyion complex from poly(sodium 2-acrylamide-2-methyl-1-propanesulfonate) and poly[2-(trimethylammonioethyl) methacrylate chloride]. Polyion complex formation between the two polyions was found to proceed stoichiometrically by the turbidimetric titration. Immobilization of catalase was achieved by conducting the complexation in the presence of the enzyme, which was established to be incorporated in the polyion complex networks. The fixed catalase showed higher thermal stability than the original enzyme. Furthermore, the stability and the activity of the fixed catalase were improved by annexing inert components such as albumin, histone, or lecithin at the time of polyion complex formation.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/app.1991.070431210
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  • 10
    Electronic Resource
    Electronic Resource
    The formation of rings of platinum dots and the control of the size of platinum particles on silica surfaces using organic - Inorganic composites (1994)
    Weinheim : Wiley-Blackwell
    Advanced Materials 6 (1994), S. 856-858 
    Details
    ISSN: 0935-9648
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/adma.19940061112
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