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  • APTS  (1)
  • CH2 rock and skeletal stretch  (1)
  • Condensation  (1)
  • Key words Gemini surfactant  (1)
  • 1
    Electronic Resource
    Electronic Resource
    Diffuse reflectance infrared Fourier transform spectral study of the interaction of 3-aminopropyltriethoxysilane on silica gel. Behavior of amino groups on the surface (1997)
    Springer
    Colloid & polymer science 275 (1997), S. 744-753 
    Details
    ISSN: 1435-1536
    Keywords: Key words DRIFT ; APTS ; silica gel ; NH2 behavior
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  Three silica gel sample systems, modified with 3-amino-propyltriethoxysilane (APTS), were prepared by sequentially sampling the reaction mixture at various time intervals, and the diffuse reflectance infrared Fourier transform (DRIFT) spectra of these samples were measured in the regions 2700–3500 and 1300–2000 cm-1. The IR bands observed at 1597 and 1629–1633 cm-1 were assigned to the deformation modes of NH2 and NH+ 3 groups, respectively. The intensities of these two bands are dependent on both the APTS concentration used in the preparation and the reaction time. The results are summarized as fol-lows. For the sample systems in which smaller APTS concentration were used, most of the NH2 groups of the aminopropyl segments are converted into the NH+ 3 groups on the surface, showing that the SiO-…H+NH2-type structure is predominantly stabilized on the surface of the silica gel. As the APTS concentration in the reaction mixture increases, the population of NH2 groups in the silane layer coated onto the surface increases. Interpretation of the CH stretch region further suggests that cyclic structures may be formed on the surface as a consequence of the formation of NH+ 3 groups.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050143
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  • 2
    Electronic Resource
    Electronic Resource
    Raman scattering study of polyaminopropylsiloxane and its compounds for characterization of 3-aminopropylsilane-modified silica gel. Utility of the CH2 rock and skeletal stretch modes (1997)
    Springer
    Colloid & polymer science 275 (1997), S. 555-560 
    Details
    ISSN: 1435-1536
    Keywords: Key words Raman ; polyamino-propylsiloxane ; GABA ; CH2 rock and skeletal stretch
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract  The Raman scattering spectra for polyaminopropylsiloxane (poly-APS) samples in the solid state and in aqueous solution and for the related compounds, γ-aminobutyric acid (GABA) and its hydrochloride salt (GABA ⋅ HCl), have been examined in the CH2 rock and skeletal stretch region. The Raman spectrum of the solid poly-APS sample may be accounted for by direct combination of the Raman spectra for GABA and GABA ⋅ HCl, whose crystal structures have been elucidated by a single-crystal X-ray diffraction study, suggesting that the APS segments of poly-APS in the solid state are in a conformationally ordered state. It has also been found that the Raman spectra of the solid and aqueous poly-APS samples in this region are useful for diagnosing the conformations of APS moieties bound onto the surface of silica gel.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050118
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  • 3
    Electronic Resource
    Electronic Resource
    Small-angle neutron-scattering study and micellar model of the gemini (phenylenedimethylene)bis(n-octylammonium)dibromide surfactant micelles in water (1999)
    Springer
    Colloid & polymer science 277 (1999), S. 361-371 
    Details
    ISSN: 1435-1536
    Keywords: Key words Gemini surfactant ; Small-Angle Neutron-Scattering ; Micellar model
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The microstructure of the micelles formed in aqueous solution by gemini surfactants with aromatic spacers, [Br(CH3)2N+(C m H2 m +1)-(Ph)-(C m H2 m +1)N+(CH3)2Br, m=8 and Ph = o-, m- or p-phenylenedimethylene] has been examined by small-angle neutron scattering. Aggregation of the gemini surfactants with an o-phenylenedimethylene spacer brings about formation of premicelles and small micelles at concentrations below the second critical micelle concentration, while above this concentration marked micellar growth and variation in shape occurs. It is suggested that the minimum aggregate formed at this critical micelle concentration may be the trimer or tetramer and that this result supports the mechanism of “gemini → submicelle → assembly” for micellar growth.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960050393
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  • 4
    Electronic Resource
    Electronic Resource
    Time-resolved near-infrared and two-dimensional near-infrared correlation spectroscopic studies of the polymerization process of silane coupling agents. Dynamic behavior of water molecules in the 3-aminopropyltriethoxysilane–ethanol–water system (2000)
    Springer
    Colloid & polymer science 278 (2000), S. 1070-1084 
    Details
    ISSN: 1435-1536
    Keywords: Key words Time-resolved near-infrared ; Two-dimensional correlation ; 3-Aminopropyltriethoxysilane ; Condensation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics
    Notes: Abstract The polymerization behavior of 3-aminopropyltriethoxysilane, a process initiated by water molecules, has been examined using time-resolved near-IR and 2D near-IR correlation spectra. By deconvolution of the time-resolved near-IR spectra, the existence of the component bands at 5189, 5265 and 5300 cm−1, whose intensities decrease markedly as the reaction proceeds, has been confirmed in the 5000–5400 cm−1 region. The band at 5189 cm−1 has been assigned to water molecules, while those at 5265 and 5300 cm−1 have been assigned to the strongly and weakly associated silanol groups, respectively. The kinetics of the hydrolysis of the ethoxy groups and of the formation of a siloxane bond have been analyzed using the time-dependent integral intensities of these three bands and the mechanisms of the reactions have been discussed. Evidence for this polymerization process is also clearly evident in the 2D near-IR correlation spectra.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s003960000371
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