Silica xerogels containing a functional group at silicon

Pauthe, M.; Phalippou, J.; Corriu, Robert J. P.; Leclercq, D.; Vioux, André

doi:10.1016/0022-3093(89)90313-x

Cited by 59 publications

(24 citation statements)

References 19 publications

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“…This result is in agreement with the hydrophobicity observed for these solids, and also with the electrochemical behaviour 2 and the chemical reactivity [3][4][5] of the corresponding hybrid gels. In the case of monophasic hybrid solids obtained by hydrolytic condensation of polysilylated precursors, the knowledge of the location of the organic moiety, at the surface or in the bulk, is of great interest (Scheme 1).…”

supporting

confidence: 90%

Characterization of the surface organization of nanostructured hybrid organic-inorganic materials by time-of-flight secondary ion mass spectrometry

Cerveau

Corriu

Dabosi

et al. 1999

Rapid Commun. Mass Spectrom.

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Time-of-flight secondary ion mass spectrometry (TOF-SIMS) has been used to analyse the surface composition of organic-inorganic hybrid solids obtained by a sol-gel process. Gels of type O(1.5)Si-R-SiO(1. 5), obtained from bis-silylated precursors (R'O)(3)-R-Si(OR')(3) (R' = Me, Et and R = (-CH(2))(n)-, n = 1, 2, 6, 10, 12;--CH=CH-; (-CH(2))(3)NH(CH(2))(3)-; 1, 1'-ferrocenyl; (CH(2))(n)-Ph-(CH(2))(n)- with Ph = 1,4-phenylene and n = 0, 1, 2; Ph = 1,3,5-phenyl and n = 0) were analysed. The results were highly dependent on the nature of the organic group. When the organic group was small or 'rigid', the main peaks detected corresponded to SiOH and SiOR' residual groups. Fragment ions from the organic group were poorly detected in this case. When the organic group was larger and more 'flexible', characteristic mass fragment ions were detected at higher relative intensities, indicative of a different organization of the organic units in the solid. TOF-SIMS clearly showed the differences between the xerogels derived from mono- and bis-silylated organic precursors : the organic group is present at the surface of mono-silylated xerogels, whereas for bis-silylated ones, the organization is dependent on the length and the flexibility of the organic units. These TOF-SIMS results are in agreement with other features already reported. Copyright 1999 John Wiley & Sons, Ltd.

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supporting

confidence: 90%

Characterization of the surface organization of nanostructured hybrid organic-inorganic materials by time-of-flight secondary ion mass spectrometry

Cerveau

Corriu

Dabosi

et al. 1999

Rapid Commun. Mass Spectrom.

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“…The NMR spectra in Figure 3 show the appearance after heating at 600°C of two resonances at 8. 31 (3.0) 59 (7) 131 (4) 205 (7) 59 (7) 177 (4) 193 (3.5) 207 (7) 191 ( from the T and D units initially present in the sample (the small peak at -57 ppm is assigned to DOH units). TG/ MS analysis (Fig.…”

Section: (T D) Resinmentioning

confidence: 99%

Thermal redistribution reactions in crosslinked polysiloxanes

Belot

Corriu

Leclercq

et al. 1992

J. Polym. Sci. A Polym. Chem.

127

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The thermolysis under argon of various polysiloxane resins containing D, T, DH, or TH units was investigated using thermogravimetric analysis combined with mass spectroscopy (TG/MS analysis) and solid‐state 29Si‐NMR. Redistribution reactions involving the exchange of SiC/SiO bonds or SiH/SiO bonds were evidenced in addition to the exchange of SiO/SiO bonds reported to date. These reactions significantly modify the initial siloxane units and lead to an escape of volatile silanes or siloxanes. The exchange of SiH/SiO bonds takes place at lower temperatures (300°C) than the exchange of SiC/SiO bonds (500°C).

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“…NMR spectra show in the expected three-functional species zone, the absence of T 1 and T 2 (which should appear at À61 and À71 ppm, respectively) and only the presence of T 3 (at À76 ppm) in a very small quantity (2%). Literature reports that Si-H groups are subject to hydrolysis under acidic conditions [20]. During our synthesis, Si-H probably vanished and new Q species are generated.…”

Section: Discussionmentioning

confidence: 95%