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Holzforschung

International Journal of the Biology, Chemistry, Physics, and Technology of Wood

Editor-in-Chief: Faix, Oskar

Editorial Board Member: Daniel, Geoffrey / Militz, Holger / Rosenau, Thomas / Salmen, Lennart / Sixta, Herbert / Vuorinen, Tapani / Argyropoulos, Dimitris S. / Balakshin, Yu / Barnett, J. R. / Berry, Richard / Burgert, Ingo / Evans, Robert / Evtuguin, Dmitry V. / Frazier, Charles E. / Fukushima, Kazuhiko / Gellerstedt, Göran / Gindl-Altmutter, Wolfgang / Glasser, W. G. / Heitner, Cyril / Holmbom, Bjarne / Isogai, Akira / Kadla, John F. / Kleen, Marjatta / Koch, Gerald / Lachenal, Dominique / Mansfield, Shawn D. / Morrell, J.J. / Niemz, Peter / Pizzi, Antonio / Ragauskas, Arthur J. / Ralph, John / Rice, Robert W. / Salin, Jarl-Gunnar / Schmitt, Uwe / Schultz, Tor P. / Schwanninger, Manfred / Sipilä, Jussi / Tamminen, Tarja / Viikari, Liisa / Welling, Johannes / Willför, Stefan / Yoshihara, Hiroshi

8 Issues per year

38% increased IMPACT FACTOR 2012: 2.416
Rank 5 out of 60 in category Forestry and 2 out of 22 in category Materials Science, Paper & Wood in the 2012 Thomson Reuters Journal Citation Report/Science Edition

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Spatial relationships between polymers in Sitka spruce: Proton spin-diffusion studies

Clemens Altaner1 / David C. Apperley2 / Michael C. Jarvis3

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Corresponding author. Chemistry Department, Glasgow University, Glasgow G12 8QQ, UK

Citation Information: Holzforschung. Volume 60, Issue 6, Pages 665–673, ISSN (Online) 1437-434X, ISSN (Print) 0018-3830, DOI: 10.1515/HF.2006.112, November 2006

Publication History

Received:
March 13, 2006
Accepted:
August 2, 2006

Abstract

The spatial arrangement of polymers in Sitka spruce (Picea sitchensis) was investigated by NMR proton spin-diffusion studies, supplemented by deuterium-exchange experiments monitored by FTIR spectroscopy. The FTIR spectra of earlywood sections after vapour-phase exchange with deuterium oxide showed that 43% of the hydroxyl groups were accessible to deuteration. This value is lower than predicted in the absence of aggregation of cellulose microfibrils into larger units, but greater than the predicted level of deuteration if 3.5-nm microfibrils surrounded by hemicellulose sheaths were aggregated into 4×4 arrays without space for deuterium oxide to penetrate between the microfibrils. The rate of proton spin diffusion between lignin and cellulose was consistent with the presence of microfibril arrays with approximately these dimensions and with lignin located outside them, in both earlywood and latewood. Proton spin-diffusion data for hemicelluloses were complicated by difficulties in assigning signals to glucomannans and xylans, but there was evidence for the spatial association of one group of hemicelluloses, including acetylated glucomannans, with cellulose surfaces, while another group of hemicelluloses was in spatial proximity to lignin. These data are consistent with a number of nanoscale models for the Sitka spruce cell wall, including a model in which glucomannans are associated with microfibril surfaces within the aggregate and water can penetrate partially between these surfaces, and one in which all non-cellulosic polymers and water are excluded from the interior of each microfibril aggregate.

Keywords: cell wall models; cellulose; hemicellulose; lignin; NMR spectroscopy; supramolecular structure of wood

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