The effects of thermal treatment on the nanomechanical behavior of bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) cell walls observed by nanoindentation, XRD, and wet chemistry

Holzforschung ◽  
2017 ◽  
Vol 71 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Yanjun Li ◽  
Chengjian Huang ◽  
Li Wang ◽  
Siqun Wang ◽  
Xinzhou Wang
Keyword(s):  
Cell Wall ◽  
Thermal Treatment ◽  
Cell Walls ◽  
Treatment Time ◽  
Lignin Content ◽  
Phyllostachys Pubescens ◽  
X Ray Diffraction ◽  
Wet Chemistry ◽  
X Ray ◽  
Wet Chemical

Abstract The effects of thermal treatment of bamboo at 130, 150, 170, and 190°C for 2, 4, and 6 h were investigated in terms of changes in chemical composition, cellulose crystallinity, and mechanical behavior of the cell-wall level by means of wet chemical analysis, X-ray diffraction (XRD), and nanoindentation (NI). Particularly, the reduced elastic modulus (Er), hardness (H), and creep behavior were in focus. Both the temperature and treatment time showed significant effects. Expectedly, the hemicelluloses were degraded and the relative lignin content was elevated, while the crystallinity of the cellulose moiety was increased upon thermal treatment. The Er and H data of the cell wall were increased after 6 h treatment at 190°C, from 18.4 to 22.0 GPa and from 0.45 to 0.65 GPa, respectively. The thermal treatment led to a decrease of the creep ratio (CIT) under the same conditions by ca. 28%. The indentation strain state (εi) also decreased significantly after thermal treatment during the load-holding stage.

Effects of thermal modification on the physical, chemical and micromechanical properties of Masson pine wood (Pinus massoniana Lamb.)

Holzforschung ◽  
2018 ◽  
Vol 72 (12) ◽  
pp. 1063-1070 ◽  
Author(s):  
Xinzhou Wang ◽  
Xuanzong Chen ◽  
Xuqin Xie ◽  
Yan Wu ◽  
Linguo Zhao ◽  
...  
Keyword(s):  
Cell Walls ◽  
Lignin Content ◽  
Chemical Properties ◽  
Pinus Massoniana ◽  
X Ray Diffraction ◽  
Masson Pine ◽  
X Ray ◽  
Pinus Massoniana Lamb ◽  
Wet Chemical ◽  
Thermally Modified Wood

AbstractIn an attempt to evaluate the effects of thermal treatment on wood cell walls (CWs), Masson pine (Pinus massonianaLamb.) wood was thermally modified (TM) at 150, 170 and 190°C for 2, 4 and 6 h, respectively. The chemical properties, cellulose crystallinity (CrI) and micromechanics of the control and thermally modified wood (TMW) were analyzed by wet chemical analysis, X-ray diffraction and nanoindentation. The relative lignin content andCrI increased after the TM partly degraded the amorphous wood polymers. The relative lignin content was higher in TMW and the equilibrium moisture content decreased. Moreover, the elastic modulus (Er) and hardness (H) of TMW were lowered along with the creep ratio decrement (CIT) of CWs. However, a severe treatment (e.g. 190°C/6 h) may negatively affect the mechanical properties of CWs caused by the partial degradation of hemicelluloses and also cellulose.

Wood Petrifaction: and aspect of biomineralogy

1979 ◽  
Vol 27 (4) ◽  
pp. 377 ◽  
Author(s):  
G Scurfield
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
X Ray Diffraction ◽  
Intercellular Substance ◽  
X Ray ◽  
Colloidal Form ◽  
Cell Lumina ◽  
Mineral Deposition ◽  
Wall Components ◽  
Scanning Electron

Light microscopy, scanning electron microscopy, X-ray diffraction and differential thermal analysis have been used to examine the structure and mineralogical make-up of 79 Australian petrified woods. Initiation of petrifaction appears to rely on the provision of a substrate with inherent porosity, with the substrate components chemically rather inert and only slowly degraded at normal temperatures and pressures under conditions probably most often acid and tending to anaerobic, and the pores sufficiently large to allow access of an appropriate mineral in ionic or colloidal form in water. Stages in the process include entry of mineral solution into the wood via splits or checks, cell lumina, and other voids; permeation of cell walls; progressive dissolution of cell wall components beginning largely with lignin and accompanied by a build-up of a mineral framework adequate for maintaining the dimensional stability of the wood; mineral deposition in cell lumina after cell wall replacement as a continuous, intermittent, perhaps separate, but not obligatory event; mineral deposition in voids present or formed by dissolution of intercellular substance as a separate, but not obligatory event; and final lithification involving loss of water and perhaps replacement of one mineral by another.

Structure of chitin in the cell walls of newly formed and mature conidia of Fusarium sulphureum

1982 ◽  
Vol 28 (5) ◽  
pp. 531-535 ◽  
Author(s):  
E. F. Schneider ◽  
W. L. Seaman
Keyword(s):  
Cell Wall ◽  
Acetic Acid ◽  
Cell Walls ◽  
Molecular Hydrogen ◽  
Spectroscopic Analysis ◽  
Conidiogenous Cell ◽  
X Ray Diffraction ◽  
Absorption Bands ◽  
X Ray ◽  
Fusarium Sulphureum

Samples of 7-day-old septate conidia (mature conidia) and newly released aseptate ones (immature conidia) of Fusarium sulphureum were hydrolyzed successively in KOH, acetic acid – H2O2, and H2SO4. The cell wall residue of the mature conidia remained intact throughout the hydrolysis but that of immature conidia dissolved in the H2SO4. Thus, the immature conidial cell wall is substantially different from that of mature conidial cells or growing hyphae and the cell wall undergoes a structural transformation following conidium release from the conidiogenous cell. X-ray diffraction analyses of the wall residues following KOH and acetic acid – H2O2 hydrolysis showed that the mature conidial wall residue had a crystalline chitin component, while the residue of the immature conidial wall was more amorphous and had smaller crystals. An X-ray diffraction pattern of the dissolved immature conidial wall that was recovered from the H2SO4 hydrolysate showed that it contained crystalline chitin.Infrared spectroscopic analysis of the mature conidial cell wall residue showed absorption bands due to inter- and intra-molecular hydrogen bonding and for hydrogen stretching associated with crystalline chitin. Such bands were lacking in the immature cell wall analogue.

Structure and composition of the cell wall of Choanephora cucurbitarum

1976 ◽  
Vol 22 (4) ◽  
pp. 486-494 ◽  
Author(s):  
D. R. Letourneau ◽  
J. M. Deven ◽  
M. S. Manocha
Keyword(s):  
Cell Wall ◽  
Cell Walls ◽  
Free Cell ◽  
Infrared Spectrophotometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Before And After ◽  
Neutral Sugars ◽  
Choanephora Cucurbitarum ◽  
Hyphal Wall

Mechanically isolated, cytoplasm-free cell walls of Choanephora cucurbitarum were analyzed qualitatively and quantitatively by use of microchemical methods, infrared spectrophotometry, and X-ray diffraction. Chemical analysis of cell wall revealed the presence of chitin (17%), chitosan (28.4%), neutral sugars (7.2%), uronic acid (2.4%), proteins (8.2%), and lipids (13.8%). The structure of hyphal wall, investigated by electron microscopy of shadowed replicas before and after alkali-acid hydrolysis, showed two distinct regions: microfibrillar and amorphous. The microfibrils, which were composed of mainly chitin, were organized into two distinct layers; an outer, thicker layer of randomly oriented microfibrils, and an inner, thin layer of parallel microfibrils. In its structure and chemical composition the cell wall of C. cucurbitarum resembles those of other zygomycetous fungi.

scholarly journals Determination of the Effects of Superheated Steam on Microstructure and Micromechanical Properties of Bamboo Cell Walls Using Quasi-Static Nanoindentation

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1742
Author(s):  
Tiancheng Yuan ◽  
Xiaorong Liu ◽  
Youming Dong ◽  
Xinzhou Wang ◽  
Yanjun Li
Keyword(s):  
Elastic Modulus ◽  
Cell Walls ◽  
Superheated Steam ◽  
Lignin Content ◽  
Crystallinity Index ◽  
X Ray Diffraction ◽  
Untreated Sample ◽  
X Ray ◽  
Micromechanical Properties

In this paper, quasi-static nanoindentation was applied for investigating the influence of superheated steam on microstructure and micromechanical properties of Moso bamboo cell walls. The changes of mico-morphology, chemical composition, cellulose crystallinity index, micro-mechanical properties of bamboo were analyzed via scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR), and nanoindentation. As expected, the content of hemicellulose and cellulose showed a downward trend, whereas the relative lignin content increased. Elastic modulus and hardness of the cell wall increased compared with that of the untreated sample. The elastic modulus and hardness of bamboo increased from 11.5 GPa to 19.5 GPa and from 0.35 GPa to 0.59 GPa. Furthermore, results showed that the creep resistance positively correlated to treatment severity.

scholarly journals The structure of the cell wall in some species of the filamentous green alga Cladophora

1940 ◽  
Vol 129 (854) ◽  
pp. 54-76 ◽  
Keyword(s):  
Cell Wall ◽  
Green Alga ◽  
Cell Elongation ◽  
Cell Walls ◽  
Opposite Sign ◽  
Periodic Change ◽  
X Ray Diffraction ◽  
X Ray ◽  
Filamentous Green Alga ◽  
Flat Spiral

With a view to extending the work on Valonia , the cell walls of several species of Cladophora have been examined in detail by means of X-ray diffraction photographs and the microscope. The walls are found to consist of layers in which the cellulose chains in any one layer are inclined to those in the preceding and subsequent layers at an angle whose average is less than 90°. The two sets of striations on the layers of the wall correspond closely to the directions of the cellulose chains. Each set of chains forms a spiral round the cell, and the spirals are of opposite sign. One tends to be flat and th e other steep. On the whole, th e steep spiral tends to become steeper on passing from the base of the filament to the tip, and the flat spiral flatter. In any one cell of the filament, the steep spiral is steepest at the end nearer the filament tip and the flat spiral flattest. Wherever such changes in inclination occur, the angle between the chains tends to remain constant. It is suggested that cell elongation is the factor causing the inclination of the steeper spiral to vary, and that the behaviour of the flatter spiral is best explained by the assumption of a protoplasmic mechanism causing a periodic change in the direction of cellulose chains through a constant angle. The development of a branch cell is reviewed and is found to proceed as the above suggestions would indicate.

Silicification of wood-cell walls

1994 ◽  
Vol 52 ◽  
pp. 428-429
Author(s):  
S. E. Keckler ◽  
D. M. Dabbs ◽  
N. Yao ◽  
I. A. Aksay
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Cell Walls ◽  
Lignin Content ◽  
Resin Composite ◽  
Middle Lamella ◽  
Cellulose Fibers ◽  
Complex Structures ◽  
Rich Region ◽  
Inorganic Precursors

Cellular organic structures such as wood can be used as scaffolds for the synthesis of complex structures of organic/ceramic nanocomposites. The wood cell is a fiber-reinforced resin composite of cellulose fibers in a lignin matrix. A single cell wall, containing several layers of different fiber orientations and lignin content, is separated from its neighboring wall by the middle lamella, a lignin-rich region. In order to achieve total mineralization, deposition on and in the cell wall must be achieved. Geological fossilization of wood occurs as permineralization (filling the void spaces with mineral) and petrifaction (mineralizing the cell wall as the organic component decays) through infiltration of wood with inorganics after growth. Conversely, living plants can incorporate inorganics into their cells and in some cases into the cell walls during growth. In a recent study, we mimicked geological fossilization by infiltrating inorganic precursors into wood cells in order to enhance the properties of wood. In the current work, we use electron microscopy to examine the structure of silica formed in the cell walls after infiltration of tetraethoxysilane (TEOS).

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

Molecules ◽  
2020 ◽  
Vol 25 (5) ◽  
pp. 1113 ◽  
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.

scholarly journals Characterization of ferrite nanoparticles for preparation of biocomposites

2017 ◽  
Vol 8 ◽  
pp. 1257-1265 ◽  
Author(s):  
Urszula Klekotka ◽  
Magdalena Rogowska ◽  
Dariusz Satuła ◽  
Beata Kalska-Szostko
Keyword(s):  
Chemical Method ◽  
Ferrite Nanoparticles ◽  
Chemical Activity ◽  
Nominal Composition ◽  
X Ray Diffraction ◽  
Wet Chemical Method ◽  
X Ray ◽  
Transmission Electron ◽  
Wet Chemical

Ferrite nanoparticles with nominal composition Me0.5Fe2.5O4 (Me = Co, Fe, Ni or Mn) have been successfully prepared by the wet chemical method. The obtained particles have a mean diameter of 11–16 ± 2 nm and were modified to improve their magnetic properties and chemical activity. The surface of the pristine nanoparticles was functionalized afterwards with –COOH and –NH2 groups to obtain a bioactive layer. To achieve our goal, two different modification approaches were realized. In the first one, glutaraldehyde was attached to the nanoparticles as a linker. In the second one, direct bonding of such nanoparticles with a bioparticle was studied. In subsequent steps, the nanoparticles were immobilized with enzymes such as albumin, glucose oxidase, lipase and trypsin as a test bioparticles. The characterization of the nanoparticles was acheived by transmission electron microscopy, X-ray diffraction, energy dispersive X-ray and Mössbauer spectroscopy. The effect of the obtained biocomposites was monitored by Fourier transform infrared spectroscopy. The obtained results show that in some cases the use of glutaraldehyde was crucial (albumin).

Thermal stability and miscibility of co-evaporated methyl ammonium lead halide (MAPbX3, X = I, Br, Cl) thin films analysed by in situ X-ray diffraction

2018 ◽  
Vol 6 (24) ◽  
pp. 11496-11506 ◽  
Author(s):  
Paul Pistor ◽  
Thomas Burwig ◽  
Carlo Brzuska ◽  
Björn Weber ◽  
Wolfgang Fränzel
Keyword(s):  
Thin Films ◽  
Thermal Stability ◽  
Thermal Treatment ◽  
Phase Evolution ◽  
X Ray Diffraction ◽  
Crystalline Phases ◽  
X Ray ◽  
Subsequent Thermal Treatment ◽  
Lead Halide

We present the identification of crystalline phases by in situ X-ray diffraction during growth and monitor the phase evolution during subsequent thermal treatment of CH3NH3PbX3 (X = I, Br, Cl) perovskite thin films.

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