Nishiyama Y, Johnson GP, French AD (2012) Diffraction from nonperiodic models of cellulose crystals. Nishiyama Y, Sugiyama J, Chanzy H, Langan P (2003) Crystal structure and hydrogen bonding system in cellulose Iα, from synchrotron X-ray and neutron fiber diffraction. Nishiyama Y, Langan P, Chanzy H (2002) Crystal structure and hydrogen-bonding system in cellulose Iβ from synchrotron X-ray and neutron fiber diffraction. Nieduszynski IA, Marchessault RH (1972) Structure of β, d(1 → 4)-xylan hydrate. Meyer KH, Misch L (1937) Positions des atomes dans le nouveau modélé spatial de la cellulose. Macrae CF, Gruno IJ, Chisholm JA, Edgington PR, McCabe P, Pidcock E, Rodriguez-Monge L, Taylor R, van de Streek J, Wood PA (2008) Mercury CSD 2.0-new features for the visualization and investigation of crystal structures. Langan P, Nishiyama Y, Chanzy H (2001) X-ray structure of mercerized cellulose II at 1 Å resolution. Kubicki JD, Mohamed MN-A, Watts HD (2013) Quantum mechanical modeling of the structures, energetics and spectral properties of Iα and Iβ cellulose. Klug HP, Alexander LE (1974) X-ray diffraction procedures for polycrystalline and amorphous materials, 2nd edn. Gardner KH, Blackwell J (1974) The structure of native cellulose. In: Atalla RH (ed) The structures of cellulose-characterization of the solid states. doi: 10.1007/s1057-yįrench AD, Roughead WA, Miller DP (1987) X-ray diffraction studies of ramie cellulose I. Wiley, New York, pp 159–167įrench AD, Santiago Cintrón M (2013) Cellulose polymorphy, crystallite size, and the segal crystallinity index. In: Scheurch C (ed) Cellulose and wood-chemistry and technology. Calculated intensities from different polymorphs can be added in varying proportions using a spreadsheet program to simulate patterns such as those from partially mercerized cellulose or various composites.ĭollase WA (1986) Correction of intensities for preferred orientation in powder diffractometry: application of the March model. Diffraction intensities, output by the Mercury program from the Cambridge Crystallographic Data Centre, have several uses including comparisons with experimental data. The calculated patterns are shown with and without preferred orientation along the fiber axis. Adoption of this convention, already used for crystal structure determinations, is also urged for routine studies of polymorph and crystallinity. Miller indices are shown for each contributing peak that conform to the convention with c as the fiber axis, a right-handed relationship among the axes and the length of a < b. The calculations used peak widths at half maximum height of both 0.1 and 1.5° 2θ, providing both highly resolved indications of the contributions of each contributing reflection to the observable diffraction peaks as well as intensity profiles that more closely resemble those from practical cellulose samples. In the present work, powder diffraction patterns from cellulose Iα, Iβ, II, III I, and III II were calculated based on the published atomic coordinates and unit cell dimensions contained in modified “crystal information files” (.cif) that are supplied in the Supplementary Information. In part, this desirable connection is thwarted by the use of different conventions for description of the unit cells of the crystal structures. However, the connection is seldom made between those efforts and the crystal structures of cellulose that have been proposed with synchrotron X-radiation and neutron diffraction over the past decade or so. Cellulose samples are routinely analyzed by X-ray diffraction to determine their crystal type (polymorph) and crystallinity.
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