Cell wall changes under compression combined with steam treatment in relation to wood hygroscopicity

Abstract Compression combined with steam (CS) treatment is postulated to be an environmentally friendly and efficient modification method to improve the dimensional stability, durability, and mechanical strength of wood. The influences of CS treatment with different radial compression ratios (RCRs) (25% and 50%) and different steam temperatures (140, 160 and 180°C) on chemical components, porosity, and hygroscopicity of earlywood and latewood in Chinese fir (Cunninghamia lanceolata (Lamb.) Hook.) were investigated respectively on a cellular level by imaging Fourier Transform Infrared (FT-IR) microscopy, Confocal Raman Microscopy (CRM), nitrogen adsorption and dynamic vapor sorption (DVS). The results indicated that the degradation of carbonyl groups of the glucuronic acid component of xylan in earlywood and latewood was mainly responsible for the low hygroscopicity of CS-treated wood. Also, a significant decrease in the amount of C=O and C=C linked to the lignin aromatic skeleton involved in either crosslinking reactions or the degradation reactions could be another contributor to the reduction in wood hygroscopicity. CS-treated wood with a steam temperature of 180°C possessed a lower hygroscopicity that correlated well with the depolymerization of crystalline and amorphous cellulose. A more deformed structure of CS-treated wood led to the formation of greater amounts of mesopores in the cell walls, which could lead to increased degradation of the chemical components of wood cell walls. Furthermore, a higher equilibrium moisture content (EMC) level was found for CS-treated wood with a 50% compression ratio compared to a 25% compression ratio.

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Anatomical and Topochemical Aspects of Japanese beech (Fagus crenata) Cell Walls After Treatment with the Ionic Liquid, 1-Ethylpyridinium Bromide

Microscopy and Microanalysis ◽

10.1017/s1431927615015275 ◽

2015 ◽

Vol 21 (6) ◽

pp. 1562-1572 ◽

Cited By ~ 4

Author(s):

Toru Kanbayashi ◽

Hisashi Miyafuji

Keyword(s):

Ionic Liquid ◽

Cell Walls ◽

Middle Lamella ◽

Morphological Characteristics ◽

Fagus Crenata ◽

Cellular Level ◽

Chemical Components ◽

Wood Fibers ◽

High Concentration ◽

Japanese Beech

AbstractChanges in the ultrastructure and chemical components, and their distribution in Japanese beech (Fagus crenata), during the ionic liquid 1-ethylpyridinium bromide ([EtPy][Br]) treatment were examined at the cellular level by light microscopy, scanning electron microscopy, and confocal Raman microscopy. Each of the tissues, including wood fibers, vessels and parenchyma cells treated with [EtPy][Br] showed specific morphological characteristics. Furthermore, lignin can be preferentially liquefied and eluted in [EtPy][Br] from the cell walls when compared to polysaccharides. However, the delignification was heterogeneous on the cell walls as lignin maintained a relatively high-concentration at the compound middle lamella, cell corners, inner surface of the secondary wall, and pits after [EtPy][Br] treatment.

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Histological aspects of the cryopreservation of potato

Acta Agronomica Hungarica ◽

10.1556/aagr.56.2008.3.10 ◽

2008 ◽

Vol 56 (3) ◽

pp. 341-348

Author(s):

P. Pepó ◽

A. Kovács

Keyword(s):

Cell Wall ◽

Low Temperatures ◽

Cell Walls ◽

Cellular Level ◽

Adaptive Mechanism ◽

Epidermal Layer ◽

Freezing And Thawing ◽

Meristematic Cells ◽

Suitable Solution ◽

Vacuolated Cells

Cryopreservation appears to be a suitable solution for the maintenance of potato germplasms. The protocol described in this paper can be applied for the vitrification and preservation of meristems. During histo-cytological studies it is possible to observe modifications at the cellular level and to understand the adaptive mechanism to low temperatures. Control potato meristem tissue contained a number of meristematic cells with a gradient of differentiation. After freezing there were a large number of vacuolated cells, some of which exhibited broken cell walls and plasmolysis. The thickening of the cell wall, giving them a sinuous appearance, was observed after freezing and thawing the meristems, with ruptures of the cuticle and epidermal layer.

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Temperature-Dependent Creep Behavior and Quasi-Static Mechanical Properties of Heat-Treated Wood

Forests ◽

10.3390/f12080968 ◽

2021 ◽

Vol 12 (8) ◽

pp. 968

Author(s):

Dong Xing ◽

Xinzhou Wang ◽

Siqun Wang

Keyword(s):

Mechanical Properties ◽

Creep Behavior ◽

Cell Walls ◽

Treated Wood ◽

Crosslinking Reaction ◽

Depth Sensing ◽

Temperature Dependent ◽

Heat Treated ◽

Static Mechanical ◽

Static Mechanical Properties

In this paper, Berkovich depth-sensing indentation has been used to study the effects of the temperature-dependent quasi-static mechanical properties and creep deformation of heat-treated wood at temperatures from 20 °C to 180 °C. The characteristics of the load–depth curve, creep strain rate, creep compliance, and creep stress exponent of heat-treated wood are evaluated. The results showed that high temperature heat treatment improved the hardness of wood cell walls and reduced the creep rate of wood cell walls. This is mainly due to the improvement of the crystallinity of the cellulose, and the recondensation and crosslinking reaction of the lignocellulose structure. The Burgers model is well fitted to study the creep behavior of heat-treated wood cell walls under different temperatures.

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Even Visually Intact Cell Walls in Waterlogged Archaeological Wood Are Chemically Deteriorated and Mechanically Fragile: A Case of a 170 Year-Old Shipwreck

Molecules ◽

10.3390/molecules25051113 ◽

2020 ◽

Vol 25 (5) ◽

pp. 1113 ◽

Cited By ~ 1

Author(s):

Liuyang Han ◽

Xingling Tian ◽

Tobias Keplinger ◽

Haibin Zhou ◽

Ren Li ◽

...

Keyword(s):

Cell Wall ◽

Cell Walls ◽

Intact Cell ◽

Nitrogen Adsorption ◽

Wet Chemistry ◽

Archaeological Wood ◽

Waterlogged Archaeological Wood ◽

X Ray Scattering ◽

Crystallite Structure ◽

Cell Wall Mechanics

Structural and chemical deterioration and its impact on cell wall mechanics were investigated for visually intact cell walls (VICWs) in waterlogged archaeological wood (WAW). Cell wall mechanical properties were examined by nanoindentation without prior embedding. WAW showed more than 25% decrease of both hardness and elastic modulus. Changes of cell wall composition, cellulose crystallite structure and porosity were investigated by ATR-FTIR imaging, Raman imaging, wet chemistry, 13C-solid state NMR, pyrolysis-GC/MS, wide angle X-ray scattering, and N2 nitrogen adsorption. VICWs in WAW possessed a cleavage of carboxyl in side chains of xylan, a serious loss of polysaccharides, and a partial breakage of β-O-4 interlinks in lignin. This was accompanied by a higher amount of mesopores in cell walls. Even VICWs in WAW were severely deteriorated at the nanoscale with impact on mechanics, which has strong implications for the conservation of archaeological shipwrecks.

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UV-microscopic analysis of acetylated spruce and birch cell walls

Holzforschung ◽

10.1515/hf.2004.073 ◽

2004 ◽

Vol 58 (5) ◽

pp. 483-488 ◽

Cited By ~ 7

Author(s):

Christian Hansmann ◽

Manfred Schwanninger ◽

Barbara Stefke ◽

Barbara Hinterstoisser ◽

Wolfgang Gindl

Keyword(s):

Cell Walls ◽

Middle Lamella ◽

Microscopic Analysis ◽

Weight Percent ◽

Cellular Level ◽

Uv Spectrum ◽

Spectral Shifts ◽

Microscopy Analysis ◽

Absorbance Peak ◽

Absorbance Spectra

Abstract Spruce and birch earlywood was acetylated to different weight percent gains using three different acetylation procedures. The absorbance spectra of secondary cell wall and compound cell corner middle lamella were determined by means of UV microscopy. Analysis of the spectra showed that the characteristic lignin absorbance peak in the UV spectrum of wood around 280 nm shifted to shorter wavelengths in acetylated samples. A distinct relationship between achieved weight percent gains after acetylation and observed spectral shifts could be established revealing a certain potential to measure acetylation on a cellular level by means of UV microscopy.

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Synergistic Hydrolysis of Carboxymethyl Cellulose and Acid-Swollen Cellulose by Two Endoglucanases (CelZ and CelY) fromErwinia chrysanthemi

Journal of Bacteriology ◽

10.1128/jb.182.20.5676-5682.2000 ◽

2000 ◽

Vol 182 (20) ◽

pp. 5676-5682 ◽

Cited By ~ 51

Author(s):

Shengde Zhou ◽

Lonnie O. Ingram

Keyword(s):

Carboxymethyl Cellulose ◽

Cell Walls ◽

Cellulase Activity ◽

Substrate Preference ◽

Erwinia Chrysanthemi ◽

General Mechanism ◽

Plant Cell Walls ◽

Enzymatic Modification ◽

Amorphous Cellulose ◽

Hydrolysis Of

ABSTRACT Erwinia chrysanthemi produces a battery of hydrolases and lyases which are very effective in the maceration of plant cell walls. Although two endoglucanases (CelZ and CelY; formerly EGZ and EGY) are produced, CelZ represents approximately 95% of the total carboxymethyl cellulase activity. In this study, we have examined the effectiveness of CelY and CelZ alone and of combinations of both enzymes using carboxymethyl cellulose (CMC) and amorphous cellulose (acid-swollen cellulose) as substrates. Synergy was observed with both substrates. Maximal synergy (1.8-fold) was observed for combinations containing primarily CelZ; the ratio of enzyme activities produced was similar to those produced by cultures of E. chrysanthemi. CelY and CelZ were quite different in substrate preference. CelY was unable to hydrolyze soluble cellooligosaccharides (cellotetraose and cellopentaose) but hydrolyzed CMC to fragments averaging 10.7 glucosyl units. In contrast, CelZ readily hydrolyzed cellotetraose, cellopentaose, and amorphous cellulose to produce cellobiose and cellotriose as dominant products. CelZ hydrolyzed CMC to fragments averaging 3.6 glucosyl units. In combination, CelZ and CelY hydrolyzed CMC to products averaging 2.3 glucosyl units. Synergy did not require the simultaneous presence of both enzymes. Enzymatic modification of the substrate by CelY increased the rate and extent of hydrolysis by CelZ. Full synergy was retained by the sequential hydrolysis of CMC, provided CelY was used as the first enzyme. A general mechanism is proposed to explain the synergy between these two enzymes based primarily on differences in substrate preference.

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Gas Permeability of Cellulose Aerogels with a Designed Dual Pore Space System

Molecules ◽

10.3390/molecules24152688 ◽

2019 ◽

Vol 24 (15) ◽

pp. 2688 ◽

Cited By ~ 1

Author(s):

Kathirvel Ganesan ◽

Adam Barowski ◽

Lorenz Ratke

Keyword(s):

Porous Materials ◽

Cell Walls ◽

Gas Permeability ◽

Pore Space ◽

Nitrogen Adsorption ◽

Space System ◽

Fixed Amount ◽

Hydrophilic Lipophilic Balance ◽

Wide Range ◽

The Impact

The gas permeability of a porous material is a key property determining the impact of the material in an application such as filter/separation techniques. In the present study, aerogels of cellulose scaffolds were designed with a dual pore space system consisting of macropores with cell walls composing of mesopores and a nanofibrillar network. The gas permeability properties of these dual porous materials were compared with classical cellulose aerogels. Emulsifying the oil droplets in the hot salt–hydrate melt with a fixed amount of cellulose was performed in the presence of surfactants. The surfactants varied in physical, chemical and structural properties and a range of hydrophilic–lipophilic balance (HLB) values, 13.5 to 18. A wide range of hierarchical dual pore space systems were produced and analysed using nitrogen adsorption–desorption analysis and scanning electron microscopy. The microstructures of the dual pore system of aerogels were quantitatively characterized using image analysis methods. The gas permeability was measured and discussed with respect to the well-known model of Carman–Kozeny for open porous materials. The gas permeability values implied that the kind of the macropore channel’s size, shape, their connectivity through the neck parts and the mesoporous structures on the cell walls are significantly controlling the flow resistance of air. Adaption of this new design route for cellulose-based aerogels can be suitable for advanced filters/membranes production and also biological or catalytic supporting materials since the emulsion template method allows the tailoring of the gas permeability while the nanopores of the cell walls can act simultaneously as absorbers.

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Softening Characteristics of Wet Wood under Quasi Static Loading

Holzforschung ◽

10.1515/hf.2000.094 ◽

2000 ◽

Vol 54 (5) ◽

pp. 557-560 ◽

Cited By ~ 14

Author(s):

S. Hamdan ◽

W. Dwianto ◽

T. Morooka ◽

M. Norimoto

Keyword(s):

Glass Transition ◽

Relaxation Process ◽

Wood Species ◽

Static Loading ◽

Chemical Structure ◽

Steam Treatment ◽

Radial Compression ◽

Softening Behavior ◽

Broad Leaf ◽

The Difference

Summary In order to examine the possible influences of temperature on the wood constituents, two groups of wood species namely softwood (needle leaf wood) and hardwood (broad leaf wood) were subjected to heat or steam treatment during large radial compression between 0°C and 200°C. Two well-defined softening regions are observed. Both species showed the glass transition Tg of lignin at ~ 90°C and ~ 60°C for softwood and hardwood respectively and a second transition region at ~ 160°C. The softening behavior between the first and second transition in softwood is in contrast with the softening behavior of hardwood. This difference reflects the difference in the distribution of the relaxation process due to lignin, which suggests the difference in chemical structure of lignin between softwood and hardwood.

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The Improvement of Durability of Marine Wood with Polymer and its Mechanism

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.79-82.1021 ◽

2009 ◽

Vol 79-82 ◽

pp. 1021-1024 ◽

Cited By ~ 1

Author(s):

Yong Feng Li ◽

Yi Xing Liu ◽

Xiang Ming Wang ◽

Xiu Rong Li

Keyword(s):

Porous Structure ◽

Dimensional Stability ◽

Cell Walls ◽

Treated Wood ◽

Untreated Wood ◽

Decay Resistance ◽

Hydroxyl Group ◽

Alkali Resistance ◽

Hydroxyl Groups ◽

Marine Corrosion

In order to improve the durability of marine wood against the long-term marine corrosion, the study explores to use two bifunctional reagents, maleic anhydride (Man) and glycidyl methacrylate(GMA), to react with wood by impregnating them into the porous structure of wood and further initiating them to polymerize with an initiator, AIBN, through a heat process. After the above modification, the durability of the marine wood treated with polymer was tested, and its mechanism was further analyzed as well. The testing results of the durability show that the acid resistance, the alkali resistance, the decay resistance against marine borers and the dimensional stability of the treated wood increases by 2.02 times, 12.39 times, 4.96 times and 3 times over untreated wood, respectively; and its Anti Swelling Efficiency (ASE) for dimensional stability reaches 53%, which almost equals the value of the wood treated by PEG-1500 under the same condition, while its leachability resistance is greatly higher than wood treated by PEG-1500. The analysis result with FTIR indicates that Man and GMA both react with wood, and Man reacts with the hydroxyl group of wood cell walls by its anhydride group, and GMA polymerizes in the porous structure of wood. The charactering result with SEM reveals that the resultant polymer fills in wood cell lumina as a solid form, which contacts tightly the wood cell walls without obvious gaps. The greatly reducing amount of hydroxyl groups after the reaction and the heavy jamming channels for water and marine borers approaching to wood cell walls both contribute to the improving durability of the modified wood.

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Application of Confocal Raman Microscopy for the Analysis of the Distribution of Wood Preservative Coatings

Coatings ◽

10.3390/coatings9100621 ◽

2019 ◽

Vol 9 (10) ◽

pp. 621 ◽

Cited By ~ 2

Author(s):

Toru Kanbayashi ◽

Atsuko Ishikawa ◽

Masahiro Matsunaga ◽

Masahiko Kobayashi ◽

Yutaka Kataoka

Keyword(s):

Surface Layer ◽

Cell Walls ◽

Wood Preservative ◽

Cellular Level ◽

Raman Microscopy ◽

Confocal Raman Microscopy ◽

Wood Coating ◽

Coating Technology ◽

Wood Coatings ◽

Confocal Raman

The distribution of wood preservative coatings in wood surface layer was assessed at the cellular level using confocal Raman microscopy. Raman images were created based on the fingerprint Raman bands of the different wood polymers and coating components (resin and pigment). The wood cell walls and the distribution of the resin and pigment were clearly visualized at the same time. It was concluded that confocal Raman microscopy is suitable for the evaluation of the microdistribution of wood coatings, providing valuable information for the improvement of wood coating technology.

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