Abstract
Structural changes across multiple length scales associated with hydrothermal pretreatments of biomass were investigated by using small- and wide-angle X-ray and neutron scattering on oriented specimens. Isotropic and anisotropic scattering components were numerically separated and then interpreted as contributions from matrix and cellulose components, respectively. Equatorial diffraction peaks present in the isotropic component became sharper after hydrothermal treatments or ammonia treatment. Before pretreatment the wet cell wall was found to be homogeneous in the 10-100 nm range and scattering below Q = 0.5 (nm-1) was dominated by surface scattering from the lumen. After pretreatment with acid or steam at 160 or 180 °C, density fluctuation developed in the cell wall at length scales above 10 nm, most likely due to lateral coalescence of microfibrils that partially co-crystallize to give larger apparent crystal sizes. A density fluctuation up to about 100 nm appeared in the isotropic component after acid and steam pretreatments due to morphological changes in the hemicellulose and lignin matrix.
Original language | English |
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Pages (from-to) | 1015-1024 |
Number of pages | 10 |
Journal | Cellulose |
Volume | 21 |
Issue number | 2 |
DOIs | |
State | Published - Apr 2014 |
Funding
The Center for Structural Molecular Biology (CSMB) and the BioSANS beam line are supported by the Office of Biological and Environmental Research, using facilities supported by the U. S. Department of Energy, managed by UT-Battelle, LLC under contract No. DE-AC05-00OR22725. Acknowledgments This research is funded by the Genomic Science Program, Office of Biological and Environmental Research, U. S. Department of Energy, under FWP ERKP752.
Keywords
- Biomass
- Cellulose
- Coarsening
- Crystallite size
- Neutron scattering
- Small angle scattering
- Thermal treatment
- X-ray diffraction