X-ray scattering and microtomography study on the structural changes of never-dried silver birch, European aspen and hybrid aspen during drying

Holzforschung ◽  
2011 ◽  
Vol 65 (6) ◽  
pp. 865-873 ◽  
Author(s):  
Kirsi Leppänen ◽  
Ingela Bjurhager ◽  
Marko Peura ◽  
Aki Kallonen ◽  
Jussi-Petteri Suuronen ◽  
...  
Keyword(s):  
Cell Wall ◽  
Tension Wood ◽  
Structural Changes ◽  
Silver Birch ◽  
Hybrid Aspen ◽  
X Ray ◽  
X Ray Scattering ◽  
European Aspen ◽  
The Impact ◽  
Ray Scattering

Abstract The impact of drying on the structure of the never-dried hardwood cell wall was studied at nanometer level by means of wide- and small-angle X-ray scattering (WAXS, SAXS), and at micrometer level by X-ray microtomography (μCT). Never-dried silver birch, European aspen and hybrid aspen samples were measured by WAXS in situ during drying in air. The samples included juvenile and mature wood, as well as normal and tension wood to allow comparison of the effects of different matrix compositions and microfibril angles. The deformations of cellulose crystallites and amorphous components of the cell wall were detected as changes in the cellulose reflections 200 and 004 and amorphous halo in the WAXS patterns. Especially, the width of the reflection 004, corresponding to the cellulose chain direction, increased due to drying in all the samples, indicating an increase of strain and disorder of the chains. Also, the cellulose unit cell shrank 0.2–0.3% during drying in this direction in all the samples except in hybrid aspen tension wood. According to the SAXS results of silver birch, the distance between micro-fibrils decreased during drying. It was detected by μCT that the mean cross-sectional maximum width of the parenchymatous rays decreased from that of never-dried to air-dried birch by roughly 16%.

Synchrotron Radiation X-Ray Scattering Techniques for Studying the Micro- and Nanostructure of Wood and their Relation to the Mechanical Properties

2008 ◽  
Vol 599 ◽  
pp. 107-125 ◽  
Author(s):  
Martin Müller
Keyword(s):  
Cell Wall ◽  
Synchrotron Radiation ◽  
Mechanical Stress ◽  
Structural Changes ◽  
Structural Parameters ◽  
Cellulose Microfibrils ◽  
X Rays ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

X-ray scattering techniques have been a very useful tool for the non-destructive analysis of the wood structure. X-rays are sensitive to structural parameters such as the composite structure of wood cell walls, the crystal structure of cellulose microfibrils and their helical arrangement in the cell wall, which is usually described by the microfibril angle (MFA). With the availability of synchrotron radiation sources novel experiments on wood have become possible. The increased flux of X-rays makes the in situ and time-resolved investigation of structural changes upon mechanical stress possible. The low-divergence synchrotron radiation X-rays can be focused down to sub-micrometer size, enabling scanning studies of the wood nanostructure with (sub-)microscopic position resolution. This chapter highlights very recent advances in the understanding of wood micro- and nanostructure, which were only possible using synchrotron radiation. Examples include the MFA determination in the individual layers of the secondary cell wall, the imaging of the helical structure of the cellulose microfibrils in the cell wall, lattice strain as induced by applied mechanical stress and the structural changes of different wood types under external tensile stress.

Photoinduced structural changes in amorphousAs2S3as measured by differential anomalous x-ray scattering

1995 ◽  
Vol 52 (14) ◽  
pp. 10025-10034 ◽  
Author(s):  
Qing Ma ◽  
Weiqing Zhou ◽  
D. E. Sayers ◽  
M. A. Paesler
Keyword(s):  
Structural Changes ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering

scholarly journals Changes in the cellulose fiber wall supramolecular structure during the initial stages of chemical treatments of wood evaluated by NMR and X-ray scattering

Cellulose ◽  
2021 ◽  
Vol 28 (7) ◽  
pp. 3951-3965
Author(s):  
Elisabet Brännvall ◽  
P. Tomas Larsson ◽  
Jasna S. Stevanic
Keyword(s):  
Supramolecular Structure ◽  
Aggregate Size ◽  
Cellulose Fiber ◽  
Effect Of Temperature ◽  
Cellulose Fibril ◽  
X Ray ◽  
X Ray Scattering ◽  
Fiber Wall ◽  
The Impact ◽  
Ray Scattering

AbstractThe effect of initial stages of pulping of spruce, resembling prehydrolysis and alkaline cooking was studied using CP/MAS 13C-NMR, X-ray scattering, FSP and carbohydrate composition in order to study the impact of the pre-treatments on the fiber wall nanostructure. Removal of fiber wall components, hemicellulose and lignin, increased the fiber wall porosity and induced cellulose fibril aggregation. The effect of temperature and pH in the treatment on cellulose fibril aggregate size appears to be secondary. It is the removal of hemicellulose that has a profound effect on the supramolecular structure of the cellulose fiber wall. As the amount of hemicellulose dissolved from wood increases, the fibril aggregate size determined by NMR increases as well, ranging from 16 to 28 nm. Specifically, a good correlation between the amount of glucomannan in the fiber wall and the fibril aggregate size is seen. The lower the amount of glucomannan, the larger the aggregate size. Glucomannan thus seems to prevent aggregation as it acts as a very efficient spacer between fibrils. Elemental fibril size determined by NMR, was quite similar for all samples, ranging from 3.6 to 4.1 nm. By combining measurement methods, a more well-resolved picture of the structural changes occurring during was obtained.

scholarly journals Tracking Metamorphic Dehydration Reactions in Real Time with Transmission Small- and Wide-Angle Synchrotron X-ray Scattering: the Case of Gypsum Dehydration

2020 ◽  
Vol 61 (6) ◽  
Author(s):  
C E Schrank ◽  
K Gioseffi ◽  
T Blach ◽  
O Gaede ◽  
A Hawley ◽  
...  
Keyword(s):  
Real Time ◽  
Wide Angle ◽  
Length Scales ◽  
X Ray ◽  
Rock Samples ◽  
X Ray Scattering ◽  
Dehydration Reactions ◽  
The Impact ◽  
Ray Scattering

Abstract We present a review of a unique non-destructive method for the real-time monitoring of phase transformations and nano-pore evolution in dehydrating rocks: transmission small- and wide-angle synchrotron X-ray scattering (SAXS/WAXS). It is shown how SAXS/WAXS can be applied to investigating rock samples dehydrated in a purpose-built loading cell that allows the coeval application of high temperature, axial confinement, and fluid pressure or flow to the specimen. Because synchrotron sources deliver extremely bright monochromatic X-rays across a wide energy spectrum, they enable the in situ examination of confined rock samples with thicknesses of ≤ 1 mm at a time resolution of order seconds. Hence, fast kinetics with reaction completion times of about hundreds of seconds can be tracked. With beam sizes of order tens to hundreds of micrometres, it is possible to monitor multiple interrogation points in a sample with a lateral extent of a few centimetres, thus resolving potential lateral spatial effects during dehydration and enlarging sample statistics significantly. Therefore, the SAXS/WAXS method offers the opportunity to acquire data on a striking range of length scales: for rock samples with thicknesses of ≤ 10-3 m and widths of 10-2 m, a lateral interrogation-point spacing of ≥ 10-5 m can be achieved. Within each irradiated interrogation-point volume, information concerning pores with sizes between 10-9 and 10-7 m and the crystal lattice on the scale of 10-10 m is acquired in real time. This article presents a summary of the physical principles underpinning transmission X-ray scattering with the aim of providing a guide for the design and interpretation of time-resolved SAXS/WAXS experiments. It is elucidated (1) when and how SAXS data can be used to analyse total porosity, internal surface area, and pore-size distributions in rocks on length scales from ∼1 to 300 nm; (2) how WAXS can be employed to track lattice transformations in situ; and (3) which limitations and complicating factors should be considered during experimental design, data analysis, and interpretation. To illustrate the key capabilities of the SAXS/WAXS method, we present a series of dehydration experiments on a well-studied natural gypsum rock: Volterra alabaster. Our results demonstrate that SAXS/WAXS is excellently suited for the in situ tracking of dehydration kinetics and the associated evolution of nano-pores. The phase transformation from gypsum to bassanite is correlated directly with nano-void growth on length scales between 1 and 11 nm for the first time. A comparison of the SAXS/WAXS kinetic results with literature data emphasises the need for future dehydration experiments on rock specimens because of the impact of rock fabric and the generally heterogeneous and transient nature of dehydration reactions in nature. It is anticipated that the SAXS/WAXS method combined with in situ loading cells will constitute an invaluable tool in the ongoing quest for understanding dehydration and other mineral replacement reactions in rocks quantitatively.

Small angle X-ray scattering study of structural changes in silica gel modified with organofunctional groups

1989 ◽  
Vol 40 ◽  
pp. 1-8 ◽  
Author(s):  
Dimas R. Vollet ◽  
José C. Moreira ◽  
Lauro T. Kubota ◽  
José A. Varela ◽  
Yoshitaka Gushikem
Keyword(s):  
Silica Gel ◽  
Small Angle ◽  
Structural Changes ◽  
X Ray ◽  
X Ray Scattering ◽  
Scattering Study ◽  
Ray Scattering

Light-Induced Structural Changes of LOV Domain-Containing Polypeptides fromArabidopsisPhototropin 1 and 2 Studied by Small-Angle X-ray Scattering†

Biochemistry ◽  
2004 ◽  
Vol 43 (47) ◽  
pp. 14881-14890 ◽  
Author(s):  
Masayoshi Nakasako ◽  
Tatsuya Iwata ◽  
Daisuke Matsuoka ◽  
Satoru Tokutomi
Keyword(s):  
Small Angle ◽  
Structural Changes ◽  
Lov Domain ◽  
X Ray ◽  
X Ray Scattering ◽  
Ray Scattering
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