Application of Small-Angle X-Ray Scattering to Predict Microfibril Angle in Acacia mangium Wood

2010 ◽  
Vol 173 ◽  
pp. 72-77
Author(s):  
Tabet A. Tamer ◽  
Aziz Abdul Haji Fauziah ◽  
Radiman Shahidan
Keyword(s):  
Cell Wall ◽  
Standard Deviation ◽  
Intensity Distribution ◽  
Small Angle ◽  
Cell Walls ◽  
Microfibril Angle ◽  
Acacia Mangium ◽  
Cellulose Microfibrils ◽  
X Ray ◽  
X Ray Scattering

Partially crystalline cellulose microfibrils are wound helically around the longitudinal axis of the wood cell. A method is presented for the measurement, using small-angle X-ray scattering (SAXS), of the microfibril angle, (MFA) and the associated standard deviation for the cellulose microfibrils in the S2 layer of the cell walls of Acacia mangium wood. The length and orientation of the microfibrils of the cell walls in the irradiated volume of the thin samples are measured using SAXS and scanning electron microscope, (SEM). The undetermined parameters in the analysis are the MFA, (M) and the standard deviation (σФ) of the intensity distribution arising from the wandering of the fibril orientation about the mean value. Nine separate pairs of values are determined for nine different values of the angle of the incidence of the X-ray beam relative to the normal to the radial direction in the sample. The results show good agreement. The curve distribution of scattered intensity for the real cell wall structure is compared with that calculated with that assembly of rectangular cells with the same ratio of transverse to radial cell wall length. It is demonstrated that for β = 45°, the peaks in the curve intensity distribution for the real and the rectangular cells coincide. If this peak position is Ф45, Then the MFA can be determined from the relation M = tan-1 (tan Ф45 / cos 45°), which is precise for rectangular cells.

scholarly journals The derivation of the cellulose microfibril angle by small-angle X-ray scattering from structurally characterized softwood cell-wall populations

2005 ◽  
Vol 38 (3) ◽  
pp. 505-511 ◽  
Author(s):  
Kenneth M. Entwistle ◽  
Stephen J. Eichhorn ◽  
Namasivayam Navaranjan
Keyword(s):  
Cell Wall ◽  
Standard Deviation ◽  
Intensity Distribution ◽  
Cell Walls ◽  
Radial Direction ◽  
Microfibril Angle ◽  
Scattered Intensity ◽  
X Ray ◽  
The Real ◽  
X Ray Scattering

A method is presented for the measurement, using small-angle X-ray scattering (SAXS), of the microfibril angle and the associated standard deviation for the cellulose microfibrils in the S2 layer of the cell walls of softwood specimens. The length and orientation of over 1000 cell walls in the irradiated volume of the specimen are measured using quantitative image analysis. From these data are calculated the azimuthal variation of the scattered intensity. The calculated values are compared with the measured values. The undetermined parameters in the analysis are the microfibril angle (M) and the standard deviation (σΦ) of the intensity distribution arising from the wandering of the fibril orientation about the mean value. The two parameters are varied to give the best fit between the calculated and the measured values. Six separate pairs of values are determined for six different values of the angle of incidence of the X-ray beam relative to the normal to the radial direction in the specimen. The results show good agreement. The azimuthal distribution of scattered intensity for the real cell-wall structure is compared with that calculated for an assembly of rectangular cells with the same ratio of transverse to radial cell-wall lengths. Despite the existence of marked differences in the intensity distributions around the zero azimuth angle, the position of the extreme flanks of the distribution is very close for the real and the rectangular cells. This means that useful values of the microfibril angle can be obtained from the curve for the real cells using the Meylan parameter T derived by drawing tangents to the flanks of the intensity distribution and using M = kT. The value of k is M/(M + 2σΦ). Since both of these parameters are determined in the work now described, k is also determined. It is also demonstrated that for β = 45° (where β is the angle between the plane face of the wood specimens and the radial direction) the peaks in the azimuthal intensity distribution for the real and the rectangular cells coincide. If this peak position is Φ45, then the microfibril angle can be determined from the relation M = tan−1(tanΦ45/cos45°), which is precise for rectangular cells.

A Study of the Nanostructure of the Cellulose of Acacia mangium Wood by X-Ray Diffraction and Small-Angle X-Ray Scattering

2011 ◽  
Vol 364 ◽  
pp. 480-484 ◽  
Author(s):  
Tabet A. Tamer ◽  
Fauziah Abdul Aziz ◽  
Radiman Shahidan
Keyword(s):  
Small Angle ◽  
Microfibril Angle ◽  
Acacia Mangium ◽  
Mean Value ◽  
Tree Age ◽  
Crystalline Cellulose ◽  
X Ray Diffraction ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

The purpose of this study was to develop practical and reliable small-angle x-ray scattering and x-ray diffraction methods to study the nanostructure of the wood cell wall and to use these methods to systematically study the nanostructure of Acacia mangium wood grown in Sabah, Malaysia. Methods to determine the microfibril angle (MFA) distribution, the crystallinity of wood, and the average size of cellulose crystallites were developed and these parameters were determined as a function of the tree age and the distance from pith towards the bark. The mean MFA in Acacia mangium increases rapidly as a function of the number of the year and after the 7th year-old it varies between 6° and 10°. The thickness of cellulose crystallites for Acacia mangium appears to be constant as a function of the tree age after 10-year-old. The obtained mean value is 3.20 nm. The size of the cellulose crystallites was also quite constant after 11 year-old. The maximum value of the width of the crystallites for Acacia mangium was 2.34 nm at the pith region, while the minimum value was 0.290 nm at the bark region. The mass fraction of crystalline cellulose in wood is the crystallinity of wood and the intrinsic crystallinity of cellulose. The crystallinity of wood increases from the 3nd year-old to the 10th year-old from the pith and is constant after the 10th year.

Hydration effects on spacing of primary-wall cellulose microfibrils: a small angle X-ray scattering study

Cellulose ◽  
2007 ◽  
Vol 14 (5) ◽  
pp. 401-408 ◽  
Author(s):  
Craig J. Kennedy ◽  
Adriana Šturcová ◽  
Michael C. Jarvis ◽  
Timothy J. Wess
Keyword(s):  
Small Angle ◽  
Cellulose Microfibrils ◽  
Primary Wall ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

Interpretation of small-angle x-ray scattering intensity distribution from fluctuating lamellae in a ternary system: sodium octyl sulfate-water-decanol

Langmuir ◽  
1991 ◽  
Vol 7 (9) ◽  
pp. 1895-1899
Author(s):  
Eric Y. Sheu ◽  
Sow Hsin. Chen ◽  
Bruce L. Carvalho ◽  
J. S. Lin ◽  
Malcolm. Capel
Keyword(s):  
Ternary System ◽  
Intensity Distribution ◽  
Small Angle ◽  
Scattering Intensity ◽  
X Ray ◽  
X Ray Scattering ◽  
System Sodium ◽  
Ray Scattering

scholarly journals Bundling of cellulose microfibrils in native and polyethylene glycol-containing wood cell walls revealed by small-angle neutron scattering

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Paavo A. Penttilä ◽  
Michael Altgen ◽  
Muhammad Awais ◽  
Monika Österberg ◽  
Lauri Rautkari ◽  
...  
Keyword(s):  
Cell Wall ◽  
Neutron Scattering ◽  
Plant Cell ◽  
Small Angle ◽  
Cell Walls ◽  
Small Angle Neutron Scattering ◽  
Plant Cell Wall ◽  
Raw Materials ◽  
Cellulose Microfibrils ◽  
Wall Structure

AbstractWood and other plant-based resources provide abundant, renewable raw materials for a variety of applications. Nevertheless, their utilization would greatly benefit from more efficient and accurate methods to characterize the detailed nanoscale architecture of plant cell walls. Non-invasive techniques such as neutron and X-ray scattering hold a promise for elucidating the hierarchical cell wall structure and any changes in its morphology, but their use is hindered by challenges in interpreting the experimental data. We used small-angle neutron scattering in combination with contrast variation by poly(ethylene glycol) (PEG) to identify the scattering contribution from cellulose microfibril bundles in native wood cell walls. Using this method, mean diameters for the microfibril bundles from 12 to 19 nm were determined, without the necessity of cutting, drying or freezing the cell wall. The packing distance of the individual microfibrils inside the bundles can be obtained from the same data. This finding opens up possibilities for further utilization of small-angle scattering in characterizing the plant cell wall nanostructure and its response to chemical, physical and biological modifications or even in situ treatments. Moreover, our results give new insights into the interaction between PEG and the wood nanostructure, which may be helpful for preservation of archaeological woods.

Untersuchung der kristallinen Strukturen in Depotfetten von Tieren mittels Röntgenbeugungsmethoden / Investigation of Crystalline Structures in Fats of Animals by X-Ray Scattering

1978 ◽  
Vol 33 (1-2) ◽  
pp. 28-38
Author(s):  
H. Wawra
Keyword(s):  
Density Distribution ◽  
Temperature Region ◽  
Intensity Distribution ◽  
Small Angle ◽  
Electron Density Distribution ◽  
Fat Crystals ◽  
X Ray ◽  
X Ray Scattering ◽  
Small Angle Region ◽  
Ray Scattering

Abstract Fat-praeparates of cow and pork have been investigated by small-angle X-ray scattering methods. Dependent on the temperature these fats show distinct X-ray interference patterns in the small-angle region. Hence complete phasediagrams of the fats in the temperature region between -20 °C and 55 °C could be estimated. Using the intensity distribution of the X-ray scattering the electron-density distribution along one direction of the ground-cells of the fat crystals were calculated.

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