Advertisement

Springer Nature is making SARS-CoV-2 and COVID-19 research free. View research | View latest news | Sign up for updates

Proton magnetic resonance techniques for characterization of water in wood: application to white spruce

Summary

Two new proton magnetic resonance techniques, relaxation spectra and relaxation selective imaging, have been used to investigate the distribution of water in samples of normal white spruce sapwood, heartwood, and juvenile wood as well as two rehydrated heartwood samples containing incipient decay and compression wood respectively. It is demonstrated that the spin-spin (T2) relaxation behavior in wood is best presented as a continuous spectrum of relaxation times. Spectra of T2 for white spruce show separate peaks corresponding to the different water environments. Bound water gives a peak with an T2 time of about 1 ms and lumen water gives a distribution of T2 times in the range of 10 to 100 ms. The lumen water T2 time is a function of the wood cell radius. Consequently, the different cell lumen radii distributions for spruce sapwood, juvenile wood, and compression wood are readily distinguishable by the shape of their T2 spectra. Water environments which are separable on a T2 spectrum may be imaged separately. Imaging has been carried out in one dimension for bound water and lumen water of a spruce sapwood sample at four different moisture contents ranging from 100% to 17%. For the first time, we demonstrate that above the fibre saturation point the moisture density profile of the bound water is largely independent of moisture content. The feasibility and utility of using these techniques for internal scanning of logs and lumber is discussed. These techniques should provide new insights into the wood drying process.

This is a preview of subscription content, log in to check access.

References

  1. Brownstein, K.R. Tarr, C. E. 1979: Importance of classical diffusion in NMR studies of water in biological cells. Physical Review A. 19: 2446–2453

  2. Fengel, D.; Wegener, G. 1984: Wood: chemistry, ultrastructure, reactions, pp. 56, l152. Berlin; New York: de Gruyter

  3. Flibotte, S.G.; Menon, R. S.; MacKay, A. L.; Hailey, J. R. T. 1990: Proton magnetic resonance of western red cedar. Wood Fiber Sci. 22:362–376

  4. Hall, L.D.; Rajanayagm, V. 1986: Evaluation of the distribution of water in wood by use of three dimensional proton NMR volume imaging. Wood Sci.Technol 20: 329–333

  5. Haygreen, J. G.; Bowyer, J. L. 1982: Forest products and wood science; a introduction, pp. 112. Ames, Iowa: The Iowa State University Press

  6. James, F.; Roos, M. 1975: Minuit: A system for function minimization and analysis of the parameter errors and correlations. Comput. Phys. Commun. 10: 343–367

  7. Lawson, C. L.; Hanson, R. J. 1974: Solving least squares problems. Englewood Cliffs, New Jersey: Prentice-Hall

  8. Menon, R. S.; MacKay, A. L.; Flibotte, S. G.; Hailey, J. R. T. 1989: Quantitative separation of NMR images of water in wood on the basis of T2. J. Magn. Reson. 82: 205–210

  9. Menon, R, S.; MacKay, A. L.; Hailey, J. R. T.; Bloom, M., Burgess, A. E.; Swanson, J. S. 1987: An NMR determination of the physiological water distribution in wood during drying. J. Appl. Polym. Sci. 33: 1146–1155

  10. Quick, J. J.; Hailey, J. R. T.; MacKay, A. L. 1990: Radial moisture profiles of cedar sapwood during drying: A proton magnetic resonance study. Wood Fiber Sci. 22:404–412

  11. Sternin, E. 1985: Data acquisition and processing: A systems approach. Rev. Sc. Instrum. 56: 2043–2049

  12. Wang, P. C.; Chang, S. T. 1986: Nulcear magnetic resonance imaging of wood. Wood Fiber Sci. 18: 308–314

  13. Whittall, K. P.; MacKay, A. L. 1989: Quantitative interpretation of NMR relaxation data. J. Magn. Reson. 84: 134–153

Download references

Author information

Additional information

We would like to thank Michael Weiss of the Biological Science Electron Microscopy Facility at the University of British Columbia for his assistance with the microscopy and image analysis. This research was supported by grants from the Natural Sciences and Engineering Research Council of Canada and the Canadian Forestry Service

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Araujo, C.D., MacKay, A.L., Hailey, J.R.T. et al. Proton magnetic resonance techniques for characterization of water in wood: application to white spruce. Wood Sci.Technol. 26, 101–113 (1992). https://doi.org/10.1007/BF00194466

Download citation

Keywords

  • Water Environment
  • Compression Wood
  • Relaxation Spectrum
  • Cell Radius
  • Juvenile Wood