Small Particle X-Ray Scattering by Fibers, Size and Shape of Microcrystallites

Heyn, A. N. J.

doi:10.1063/1.1722032

Cited by 58 publications

(31 citation statements)

References 26 publications

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“…The value j=0 was set to be perpendicular to the fiber axis. From the point of view of SAXS the cell wall is assumed to consist of cellulose microfibrils, which are assumed to be thin, elongated cylinders, and the surrounding matrix (Heyn 1955). Scattering from an oriented cylindrical microfibril causes an intensity stripe, which is perpendicular to the cylinder axis.…”

Section: Small-angle X-ray Scatteringmentioning

confidence: 99%

Effect of growth rate on mean microfibril angle and cross-sectional shape of tracheids of Norway spruce

Sarén

Serimaa

Andersson

et al. 2004

Trees - Structure and Function

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The variation of the mean microfibril angle (MFA) and the shape of the cross-section of lumen with the distance from the pith in fast grown Norway spruce were studied by X-ray scattering and optical microscopy. The samples were from stems of a clone of Norway spruce [ Picea abies (L.) Karst.] grown in a fertile site at Nurmijärvi, southern Finland Both the mean MFA and the circularity index of the lumen of the fast-grown trees decreased more gradually as the distance from the pith increased than those in reference trees grown in a medium fertility site. However, in mature wood the mean MFA reached the same level in fast-grown trees as in reference trees (5-10) but the cross-sections of the cells remained more circular in fast-grown trees than in reference trees. The dependence of the mean MFA on the distance from the pith was similar for earlywood and latewood, but the values of the mean MFA of latewood were systematically smaller than those of earlywood. Two different X-ray diffraction geometries were compared from the points of view of biology and data analysis.Keywords X-ray diffraction · Microfibril angle · Circularity index · Cross-sectional shape of the lumen · Growth rate

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Section: Small-angle X-ray Scatteringmentioning

confidence: 99%

Effect of growth rate on mean microfibril angle and cross-sectional shape of tracheids of Norway spruce

Sarén

Serimaa

Andersson

et al. 2004

Trees - Structure and Function

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“…At q & 1-2 nm -1 , the scattering signal shows a shoulder which can be assumed to come mainly from the fibril structures. At very large q (q * 2 nm -1 ), the pattern is overlapped by diffuse WAXS contributions (Heyn 1955a) which lead to a deviation from the -4 power law, significantly after NaOH treatment. When the Deli.…”

Section: Wide-angle X-ray Scattering (Waxs)mentioning

confidence: 99%

The implication of chemical extraction treatments on the cell wall nanostructure of softwood

et al. 2007

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Spruce wood was subjected to welldefined extraction treatments with sodium chlorite (NaClO 2 ) for delignification, as well as with sodium hydroxide (NaOH) at different concentrations for extraction of hemicelluloses. The corresponding changes of the macromolecular polymer assembly were investigated by small-angle X-ray scattering (SAXS). Measurements with Fourier-transform infrared (FTIR) spectroscopy and wide-angle scattering (WAXS) gave qualitative information about the effectiveness of the extraction process, while the scattering experiments provided information about the regularity and typical dimensions of the molecular structures. The scattering data indicated that delignification had only a moderate effect on the structural organisation of the cell wall, while further extraction with NaOH induced considerable nanostructural changes.

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“…Whereas X-ray scattering methods have been used successfully to determine average structural parameters such as the mean micro®bril angle (see for example Cave, 1997;Evans, 1994;Jakob et al, 1994Jakob et al, , 1995 or the mean diameter of the cellulose ®brils (Heyn, 1955;Jakob et al, 1994), they have up to now been inappropriate for the investigation of the helical orientation of the cellulose ®brils. The X-ray beam obtained from a conventional laboratory source always irradiated a number of complete cells.…”

Section: Introductionmentioning

confidence: 99%

Imaging of the helical arrangement of cellulose fibrils in wood by synchrotron X-ray microdiffraction

et al. 1999

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A complete image of the helical arrangement of cellulose ®brils in the S2 layer of adjacent wood cells of Picea abies (Norwegian spruce) was obtained by applying position-resolved synchrotron X-ray microdiffraction on cells in cross section. In contrast to conventional ®ber diffraction studies, the incident beam was parallel to the longitudinal cell axis, resulting in a glancing angle " far from 90 with respect to the cellulose ®brils. This special choice of diffraction geometry allowed us to take advantage of an asymmetry effect in the two-dimensional diffraction patterns arising from the curvature of the Ewald sphere to obtain information on the local orientation of the cellulose ®brils. The small size of the beam, smaller than the thickness of a single cell wall, allowed mesh scans over intact transverse sections of adjacent wood cells with a microscopic position resolution. The scan yielded a map of diffraction patterns that could readily serve as a microscopic image. Each of the diffraction patterns was then used to evaluate the local orientation of the cellulose ®brils at the actual beam position. The combination of these results gave an image of cellulose ®brils forming (Z) helices in several adjacent wood cells.

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Small Particle X-Ray Scattering by Fibers, Size and Shape of Microcrystallites

Cited by 58 publications

References 26 publications

Effect of growth rate on mean microfibril angle and cross-sectional shape of tracheids of Norway spruce

Effect of growth rate on mean microfibril angle and cross-sectional shape of tracheids of Norway spruce

The implication of chemical extraction treatments on the cell wall nanostructure of softwood

Imaging of the helical arrangement of cellulose fibrils in wood by synchrotron X-ray microdiffraction

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