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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
Original

Abstract

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.

Keywords

Cellulose Wood Composite 29Si Nucleus Cellulose Composite Magic Angle Sample Spin 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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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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