Wood Science and Technology

, Volume 48, Issue 5, pp 1033–1047 | Cite as

Evidence of Si–O–C bonds in cellulosic materials modified by sol–gel-derived silica

  • Michael Bücker
  • Christian Jäger
  • Dietmar Pfeifer
  • Brita Unger


The present study contributes to the controversial discussion in the literature whether Si–O–C bonds in wood–silica–gel composites exist. 13C NMR is a suitable method to proof such bonds. Because of the low concentration of 13C isotopes in natural wood, 13C cellulose was used as 13C-enriched substitute. A tailored sol for the impregnation of that cellulose was chosen by liquid 29Si NMR pre-investigations of various sols whose reactivity and stability were time-dependently analysed. It is based on a sub-stoichiometric hydrolysis of tetraethoxysilane (TEOS) with 1 mol water per mol TEOS. Thermal analyses were performed to show a comparability of the thermal behaviour of wood–silica–gel and cellulose–silica–gel composites. There are two strong hints of the existence of stable Si–O–C bonds: (1) by thermal analysis, a shift in the fire behaviour of 100 K can be observed with a change in pyrolysis behaviour of the composite and (2) the proof by REDOR NMR that a dipolar coupling between 29Si and 13C nuclei exists.


Cellulose Wood Composite 29Si Nucleus Cellulose Composite Magic Angle Sample Spin 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2014

Authors and Affiliations

  • Michael Bücker
    • 1
  • Christian Jäger
    • 1
  • Dietmar Pfeifer
    • 1
  • Brita Unger
    • 1
  1. 1.BAM Federal Institute for Materials Research and TestingBerlinGermany

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