X-ray microdiffraction reveals the orientation of cellulose microfibrils and the size of cellulose crystallites in single Norway spruce tracheids

Abstract

The microfibril angle (MFA) distribution and the size of cellulose crystallites in isolated double cell walls of Norway spruce (Picea abies [L.] Karst.) tracheids were determined by synchrotron X-ray microdiffraction using the reflections 200 and 004. Samples were 25 lm thick longitudinal sections of earlywood from annual rings 6-18 of several stems. The asymmetric MFA distributions extended from -20°to 90°. The mean MFA of tangential cell walls decreased from an average of 24°into 19°from the pith to the bark. The mode of the MFA distribution was about 10°smaller than the mean MFA. The standard deviation of the MFA distribution varied between 18°and 25°. The mean MFA and the mode of the MFA distribution were larger in radial than in tangential cell walls. MFA distributions of mature wood samples exhibited a separate small peak at around 90°. The average width and length of cellulose crystallites varied between 28.9-30.9 Å and 192-284 Å , respectively. Both increased slightly as a function of annual ring number from the pith up to the 15th annual ring. An irrigation-fertilisation treatment of some of the stems resulted in longer cellulose crystallites compared to the untreated stems.

Maturation Stress Generation in Poplar Tension Wood Studied by Synchrotron Radiation Microdiffraction

“…In order to further understanding, direct observations of the mechanical state of the different cell wall layers and their evolution during the formation of the tension wood fibers are needed. X-ray diffraction can be used to investigate the orientation of microfibrils (Cave, 1966(Cave, , 1997a(Cave, , 1997bPeura et al, 2007Peura et al, , 2008aPeura et al, , 2008b and the lattice spacing of crystalline cellulose. The axial lattice spacing d 004 is the distance between successive monomers along a cellulose microfibril and reflects its state of mechanical stress (Clair et al, 2006a;Peura et al, 2007).…”

Comparison of the structure and flexural properties of Moso, Guadua and Tre Gai bamboo

“…Rather the MFA distribution was characterized by subtracting a linear background from the azimuthal profiles and fitting Gaussian peak pairs to the data, similar to the method in Peura et al, 2008 andY. Wang et al, 2012 and the results correspond to the total contribution of all the cell wall layers.…”

From diffraction to imaging: New avenues in studying hierarchical biological tissues with x-ray microbeams (Review)

“…[13][14][15][16][17] User applications at the ID13 beamline include many fields of modern materials science covering among others metals, 18 carbon fibers, 19 synthetic polymers, [20][21][22] as well as biopolymers and biological tissues. [23][24][25][26][27][28][29] In the meanwhile, x-ray microbeams with high photon flux are available also at other sites, and dedicated instruments for scanning SAXS/WAXS have been built 30 or are in the construction phase. Particularly important for the success of microbeam SAXS/WAXS techniques is also the recent development of high resolution area detectors for x-ray scattering.…”