29Si NMR study on co-hydrolysis processes in Si(OEt)4-RSi(OEt)3-EtOH-water-HCl systems (R=Me, Ph): Effect of R groups

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    Abstract

    Hydrolysis and initial polycondensation processes in the Si(OEt)4 (TEOS)-RSi(OEt)3-EtOH-water-HCl systems (R=Me, Ph) [TEOS:RSi(OEt)3:EtOH:water:HCl=1:1:24:x:y(x=12, 2/3; y=2 × 10-3, 4 × 10-3, 8 × 10-2)] have been investigated by using 29Si NMR spectroscopy. For comparison, the alkoxysilanes [TEOS, MeSi(OEt)3 (MTES), PhSi(OEt)3 (PTES)] were hydrolysed separately in a similar manner. In a water-rich TEOS-MTES system (water:Si=12:1), a silanol-terminated codimer [Me(HO)2SiOSi(OH)3] was detected as well as (HO)3SiOSi(OH)3 and Me(HO)2SiOSi(OH)2Me, suggesting that the hydrolysed monomers were condensed rather randomly. In contrast, in a water-rich TEOS-PTES system, hydrolysed monomers derived from TEOS and those from PTES were condensed independently; a silanol-terminated codimer [Ph(HO)2SiOSi(OH)3] did not form, and only (HO)3SiOSi(OH)3 and Ph(HO)2SiOSi(OH)2Ph were detected. These observations in the TEOS-PTES system suggest the presence of the association of the phenyl groups. In water-restricted systems (water:Si=1:3), monomers were only partially hydrolysed, and ethoxy-terminated codimers [R(EtO)2SiOSi(OEt)3 (R=Me, Ph)] formed in both the TEOS-MTES and the TEOS-PTES systems.

    Original languageEnglish
    Pages (from-to)53-59
    Number of pages7
    JournalJournal of Materials Chemistry
    Volume7
    Issue number1
    Publication statusPublished - 1997 Jan

    Fingerprint

    pH effects
    hydrolysis
    Hydrolysis
    Nuclear magnetic resonance
    nuclear magnetic resonance
    Water
    water
    monomers
    Monomers
    Polycondensation
    Nuclear magnetic resonance spectroscopy
    Association reactions

    ASJC Scopus subject areas

    • Physical and Theoretical Chemistry
    • Materials Chemistry
    • Materials Science(all)

    Cite this

    @article{9cd40f934195466b8a3da67a65a249fb,
    title = "29Si NMR study on co-hydrolysis processes in Si(OEt)4-RSi(OEt)3-EtOH-water-HCl systems (R=Me, Ph): Effect of R groups",
    abstract = "Hydrolysis and initial polycondensation processes in the Si(OEt)4 (TEOS)-RSi(OEt)3-EtOH-water-HCl systems (R=Me, Ph) [TEOS:RSi(OEt)3:EtOH:water:HCl=1:1:24:x:y(x=12, 2/3; y=2 × 10-3, 4 × 10-3, 8 × 10-2)] have been investigated by using 29Si NMR spectroscopy. For comparison, the alkoxysilanes [TEOS, MeSi(OEt)3 (MTES), PhSi(OEt)3 (PTES)] were hydrolysed separately in a similar manner. In a water-rich TEOS-MTES system (water:Si=12:1), a silanol-terminated codimer [Me(HO)2SiOSi(OH)3] was detected as well as (HO)3SiOSi(OH)3 and Me(HO)2SiOSi(OH)2Me, suggesting that the hydrolysed monomers were condensed rather randomly. In contrast, in a water-rich TEOS-PTES system, hydrolysed monomers derived from TEOS and those from PTES were condensed independently; a silanol-terminated codimer [Ph(HO)2SiOSi(OH)3] did not form, and only (HO)3SiOSi(OH)3 and Ph(HO)2SiOSi(OH)2Ph were detected. These observations in the TEOS-PTES system suggest the presence of the association of the phenyl groups. In water-restricted systems (water:Si=1:3), monomers were only partially hydrolysed, and ethoxy-terminated codimers [R(EtO)2SiOSi(OEt)3 (R=Me, Ph)] formed in both the TEOS-MTES and the TEOS-PTES systems.",
    author = "Yoshiyuki Sugahara and Tsuyoshi Inoue and Kazuyuki Kuroda",
    year = "1997",
    month = "1",
    language = "English",
    volume = "7",
    pages = "53--59",
    journal = "Journal of Materials Chemistry",
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    publisher = "Royal Society of Chemistry",
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    TY - JOUR

    T1 - 29Si NMR study on co-hydrolysis processes in Si(OEt)4-RSi(OEt)3-EtOH-water-HCl systems (R=Me, Ph)

    T2 - Effect of R groups

    AU - Sugahara, Yoshiyuki

    AU - Inoue, Tsuyoshi

    AU - Kuroda, Kazuyuki

    PY - 1997/1

    Y1 - 1997/1

    N2 - Hydrolysis and initial polycondensation processes in the Si(OEt)4 (TEOS)-RSi(OEt)3-EtOH-water-HCl systems (R=Me, Ph) [TEOS:RSi(OEt)3:EtOH:water:HCl=1:1:24:x:y(x=12, 2/3; y=2 × 10-3, 4 × 10-3, 8 × 10-2)] have been investigated by using 29Si NMR spectroscopy. For comparison, the alkoxysilanes [TEOS, MeSi(OEt)3 (MTES), PhSi(OEt)3 (PTES)] were hydrolysed separately in a similar manner. In a water-rich TEOS-MTES system (water:Si=12:1), a silanol-terminated codimer [Me(HO)2SiOSi(OH)3] was detected as well as (HO)3SiOSi(OH)3 and Me(HO)2SiOSi(OH)2Me, suggesting that the hydrolysed monomers were condensed rather randomly. In contrast, in a water-rich TEOS-PTES system, hydrolysed monomers derived from TEOS and those from PTES were condensed independently; a silanol-terminated codimer [Ph(HO)2SiOSi(OH)3] did not form, and only (HO)3SiOSi(OH)3 and Ph(HO)2SiOSi(OH)2Ph were detected. These observations in the TEOS-PTES system suggest the presence of the association of the phenyl groups. In water-restricted systems (water:Si=1:3), monomers were only partially hydrolysed, and ethoxy-terminated codimers [R(EtO)2SiOSi(OEt)3 (R=Me, Ph)] formed in both the TEOS-MTES and the TEOS-PTES systems.

    AB - Hydrolysis and initial polycondensation processes in the Si(OEt)4 (TEOS)-RSi(OEt)3-EtOH-water-HCl systems (R=Me, Ph) [TEOS:RSi(OEt)3:EtOH:water:HCl=1:1:24:x:y(x=12, 2/3; y=2 × 10-3, 4 × 10-3, 8 × 10-2)] have been investigated by using 29Si NMR spectroscopy. For comparison, the alkoxysilanes [TEOS, MeSi(OEt)3 (MTES), PhSi(OEt)3 (PTES)] were hydrolysed separately in a similar manner. In a water-rich TEOS-MTES system (water:Si=12:1), a silanol-terminated codimer [Me(HO)2SiOSi(OH)3] was detected as well as (HO)3SiOSi(OH)3 and Me(HO)2SiOSi(OH)2Me, suggesting that the hydrolysed monomers were condensed rather randomly. In contrast, in a water-rich TEOS-PTES system, hydrolysed monomers derived from TEOS and those from PTES were condensed independently; a silanol-terminated codimer [Ph(HO)2SiOSi(OH)3] did not form, and only (HO)3SiOSi(OH)3 and Ph(HO)2SiOSi(OH)2Ph were detected. These observations in the TEOS-PTES system suggest the presence of the association of the phenyl groups. In water-restricted systems (water:Si=1:3), monomers were only partially hydrolysed, and ethoxy-terminated codimers [R(EtO)2SiOSi(OEt)3 (R=Me, Ph)] formed in both the TEOS-MTES and the TEOS-PTES systems.

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