Yoshiharu Nishiyama

Yoshiharu Nishiyama
French National Centre for Scientific Research | CNRS · Centre de Recherches sur les Macromolécules Végétales

PhD

About

176
Publications
34,420
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
15,279
Citations
Additional affiliations
October 2018 - present
French National Centre for Scientific Research
Position
  • DR2
October 2004 - September 2018
French National Centre for Scientific Research
Position
  • CR1
April 2000 - September 2004
The University of Tokyo
Position
  • Professor (Assistant)
Education
April 1997 - March 2000
The University of Tokyo
Field of study
  • Biomaterials Science
April 1995 - March 1997
The University of Tokyo
Field of study
  • Biomaterials Science
April 1993 - March 1995
The University of Tokyo
Field of study
  • Forest Products Science

Publications

Publications (176)
Article
Polysaccharides are the most abundant class of biopolymers, holding an important place in biological systems and sustainable material development. Their spatial organization and intra- and intermolecular interactions are thus of great interest. However, conventional single crystal crystallography is not applicable since polysaccharides crystallize...
Article
Full-text available
Crab chitin was sulfated under heterogeneous conditions using sulfamic acid in N’N-dimethylformamide to selectively sulfate the microfibril surface. The degree of sulfation followed a first order kinetics assuming a limited available reaction sites on the surface, and leveled off at a bulk degree-of-substitution of 0.4, corresponding to 2 mol/kg of...
Preprint
Crab chitin was sulfated under heterogeneous conditions using sulfamic acid in N'N-dimethylformamide to selectively sulfate the microfibril surface. The degree of sulfation followed a first order kinetics assuming a limited available reaction sites on the surface, and leveled off at a bulk degree-of-substitution of 0.4, corresponding to 2 mol/kg of...
Article
Chain-folded lamellar V-amylose single crystals were prepared by adding butan-1-ol to hot dilute aqueous solutions of native amylose. The base-plane electron and X-ray diffraction patterns recorded from hydrated specimens agreed with a P212121 space group and an orthorhombic unit cell. A molecular model resulting from an exhaustive search of helix...
Article
Nanocomposites based on components from nature, which can be recycled are of great interest in new materials for sustainable development. The range of properties of nacre-inspired hybrids of 1D cellulose and 2D clay platelets are investigated in nanocomposites with improved nanoparticle dispersion in the starting hydrocolloid mixture. Films with a...
Article
Full-text available
Dispersion and electrostatic interactions both contribute significantly to the tight assembly of macromolecular chains within crystalline polysaccharides. Using dispersion-corrected density functional theory (DFT) calculation, we estimated the elastic tensor of the four crystalline cellulose allomorphs whose crystal structures that are hitherto ava...
Article
The elastic properties of crystals are fundamental for structural material. However, in the absence of macroscopic single crystals, the experimental determination of the elastic tensor is challenging because the measurement depends on the transmission of stress inside the material. To avoid arbitrary hypotheses about stress transfer, we combine hyd...
Article
Full-text available
Transparent wood biocomposites based on PMMA combine high optical transmittance with excellent mechanical properties. One hypothesis is that despite poor miscibility the polymer is distributed at the nanoscale inside the cell wall. Small-angle neutron scattering (SANS) experiments are performed to test this hypothesis, using biocomposites based on...
Article
Rectangular V-amylose single crystals were prepared by adding racemic ibuprofen to hot dilute aqueous solutions of native and enzymatically-synthesized amylose. The lamellar thickness increased with increasing degree of polymerization of amylose and reached a plateau at about 7 nm, consistent with a chain-folding mechanism. The CP/MAS NMR spectrum...
Article
Full-text available
The nanometric internal structure of polymeric fibres is fundamental for their mechanical properties. Two-dimensional small angle neutron scattering patterns were collected to obtain structural parameters of the elementary fibrils in regenerated cellulose fibres prepared by various fibre spinning technologies. Scattering features were fitted to mod...
Article
A new type of polysaccharide (hemicellulose) nanocrystal, bearing the shape of an anisotropic nanoflake, emerged from a dimethyl sulfoxide (DMSO) dispersion of wood-based xylan through heat-induced crystallization. The dimensions of these xylan nanocrystals were controlled by the crystallization conditions. Sharp signals in solid-state NMR indicate...
Chapter
Over the last decade, the structural refinement of cellulose allomorphs and their analogs has been advanced using high-resolution fiber diffraction. This also includes structures of crystals complexed with small molecules, which can inherently involve disorders. Computational methods, including density functional theory, in combination with molecul...
Article
Full-text available
Drying cellulosic materials from their water-swollen state can collapse their ultrastructure and alter their macroscopic material properties such as mechanical strength and water-retention ability. However, at the single-crystal or molecular level, little is known about the deformation of cellulose upon drying. We thus investigate herein the drying...
Article
The classical method of producing cellulose oligomers through hydrolysis of microcrystalline cellulose (MCC) in phosphoric acid has been reexamined. Hydrolysis products are fractionated by precipitation to yield two types of cellulose oligomers with different average degrees of polymerization (DP). The number-and weight-averaged molecular weights o...
Article
Full-text available
Hierarchical carbohydrate architectures serve multiple roles in Nature. Hardly any correlations between the carbohydrate chemical structures and the material properties are available due to the lack of standards and suitable analytic techniques. Therefore, designer carbohydrate materials remain highly unexplored, as compared to peptides and nucleic...
Article
Full-text available
Hemicellulose, one of the most abundant biopolymers next to cellulose, has been considered as a potential substitute to synthetic polymers. Film casting from water is the most basic route for material applications of xylan. However, depending on plant sources and separation methods, xylans do not always form films and the related mechanism is uncle...
Article
Hierarchical carbohydrate architectures serve multiple roles in Nature. Hardly any correlations between the carbohydrate chemical structures and the material properties are available due to the lack of standards and suitable analytic techniques. Therefore, designer carbohydrate materials remain highly unexplored, as compared to peptides and nucleic...
Article
Cellulose in plant cell walls is crystalline microfibrils with diameters of 3~4 nm and lengths of around 1-10 μm. These microfibrils are known to be the backbone of cell walls, and their multiscale three-dimensional organization plays critical role in cell wall functions including plant growth and recalcitrance to degradation. The mesoscale organiz...
Article
Cellulose and Ionic liquids can form new types of complex crystals growing in form of spherulites. Microfocus X-ray diffraction on selected location of a spherulite, formed from cellulose solution in 1-allyl-3-methylimidazolium chloride (AmimCl) by water vapor diffusion, gave diffraction patterns of fiber-type texture that could be used to index th...
Article
Full-text available
Air-dried samples of 20 hardwood species were saturated with water and subjected to thermal treatment in an autoclave at 200 °C for 2 hours under a saturated vapor pressure (1.6 MPa). Gelatinous layers were observed under optical microscope for Kalopanax septemlobus and Celtis sinensis samples, which were considered to be tension wood. The other 18...
Article
Full-text available
In the original publication of the article, the acknowledgment missed one of the funding agencies. The correct acknowledgement should be.
Article
Full-text available
Nacre-inspired clay nanocomposites have excellent mechanical properties, combined with optical transmittance, gas barrier properties, and fire retardancy, but the mechanical properties are still below predictions from composite micromechanics. The properties of montmorillonite clay/nanocellulose nanocomposite hybrids are investigated as a function...
Article
Full-text available
Background Lignocellulose biomass is known as a recalcitrant material towards enzymatic hydrolysis, increasing the process cost in biorefinery. In nature, filamentous fungi naturally degrade lignocellulose, using an arsenal of hydrolytic and oxidative enzymes. Assessment of enzyme hydrolysis efficiency generally relies on the yield of glucose for a...
Article
Full-text available
We followed the cellulose structure formation induced by water diffusion into Lyocell dopes based on both N-Methylmorpholine N-oxide (NMMO) and 1,5-diazabicyclo[4.3.0]non-5-ene acetate ([DBNH][OAc], by using scanning simultaneous small- and wide-angle scattering (SAXS-WAXS) experiment along the diffusion gradient. The water content at each point wa...
Article
The periodate oxidation of cellulose, which leads to the opening of the glucosyl rings to yieldtwo aldehyde groups in the so called dialdehyde cellulose, stands as one of the major and promising pathways for the derivatization of cellulose for the design of new biosourced materials. Despite the wide use of this method and the simplicity of its chem...
Article
The hydrogen-bonding network in anhydrous chitosan crystal was studied using a combination of neutron crystallography and quantum chemical calculation. The locations of the hydroxyl hydrogen were directly resolved using Fourier omit maps applied to neutron diffraction data, whereas the amino hydrogen atoms were determined based on geometrical optim...
Article
The periodate oxidation of microfibrillated cellulose followed by a reduction treatment was implemented to produce a new type of sterically-stabilized cellulosic nanorodsnanocrystals, which were characterized at the molecular and colloidal length scales. Solid-state NMR data showed that these treatments led to objects consisting of native cellulose...
Article
Full-text available
The bending of rod-like native cellulose crystals with degree of polymerization 40 and 160 using molecular dynamics simulations resulted in a deformation-induced local amorphization at the kinking point and allomorphic interconversion between cellulose Iα and Iβ in the unbent segments. The transformation mechanism involves a longitudinal chain slip...
Article
Full-text available
Cellulose microfibrils are the principal structural building blocks of wood and plants. Their crystalline domains provide outstanding mechanical properties. Cellulose microfibrils have thus a remarkable potential as eco-friendly fibrous reinforcements for structural engineered materials. However, the elastoplastic properties of cellulose crystals r...
Article
The contribution of hydrogen bonds and the London dispersion force in the cohesion of cellulose is discussed in the light of the structure, spectroscopic data, empirical molecular-modelling parameters and thermodynamics data of analogue molecules. The hydrogen bond of cellulose is mainly electrostatic, and the stabilization energy in cellulose for...
Article
Full-text available
The successive extraction and re-adsorption of a linear β-(1 → 4) xylan extracted from microfibrillated birch pulp was investigated using solid-state CP/MAS 13C NMR spectroscopy, specific surface area measurements, and atomistic molecular dynamics (MD) simulations. The NMR spectra confirmed that when in contact with cellulose after re-adsorption, t...
Article
Full-text available
Six types of CNCs with different sizes were prepared from tunicins by sulfuric acid hydrolysis and subsequent sonication in water. The size distributions of CNCs were comprehensively evaluated by turbidimetry, small angle X-ray scattering, and microscopy to predict their intrinsic viscosities. Experimental intrinsic viscosities [η] of the CNC dispe...
Article
Crystal models of cellulose Iβ and II, which contain various hydrogen bonding (HB) networks, were analyzed using density functional theory and Car–Parrinello molecular dynamics (CPMD) simulations. From the CPMD trajectories, the power spectra of the velocity correlation functions of hydroxyl groups involved in hydrogen bonds were calculated. For th...
Article
We found a very fast benzylation of cellulose in a tetraalkyl-onium hydroxide solvent system, 47% tetra-n-butylphosphonium hydroxide aqueous solution. Benzyl cellulose (BC) with a degree of substitution (DS) above 2.5 was obtained within 10 min at ambient temperature (20–25 °C) using ~9 molar equivalents of benzyl bromide to the anhydroglucose unit...
Article
The adsorption of urea on cellulose at room temperature has been studied using adsorption isotherm experiments and molecular dynamics (MD) simulations. Immer5sion of cotton cellulose into bulk urea solutions with concentrations between 0.01 g/mL and 0.30 g/mL led to a decrease of urea concentration in all solutions, allowing the adsorption of urea...
Article
The native polymorphic structures of chitin, namely α- and β-chitin, were studied with X-ray diffraction (XRD), infrared and Raman spectroscopies, and sum-frequency generation (SFG) vibrational spectroscopy. The currently proposed model of α-chitin crystal based on X-ray and electron diffraction study has an antiparallel chain arrangement imposed b...
Article
The dimensions of nanocelluloses are important factors in controlling their material properties. The present study reports a fast and robust method for estimating the widths of individual nanocellulose particles based on the turbidities of their water dispersions. Seven types of nanocellulose, including short and rigid cellulose nanocrystals and lo...
Article
The deformation behaviour of cellulose nanocrystals under bending loads was investigated by using atomistic molecular dynamics (MD) simulations and finite element analysis (FEA), and compared with electron micrographs of ultrasonicated microfibrils. The linear elastic, non-linear elastic, and plastic deformation regions were observed with increasin...
Article
The ultrastructural transformation of wood cellulose crystals by hydrothermal treatment was followed by synchrotron and standard X-ray scattering experiments. When treated at 200 °C for 2 h in the presence of an excess of water, a significant sharpening of the equatorial reflections of crystalline cellulose was observed, and the average crystallite...
Article
The high-resolution structure of an α-chitin/hydrazine complex has been determined to reveal the molecular interactions between hydrazine molecules and chitin chains. The complexation with guest hydrazine molecules improves the crystallinity of α-chitin from the original form, so that the primary hydroxyl group is clearly located in the gt position...
Article
We determined the crystal structure of anhydrous chitosan at atomic resolution, using X-ray fiber diffraction data extending to 1.17 Å resolution. The unit cell [a = 8.129(7) Å, b = 8.347(6) Å, c = 10.311(7) Å, space group P21 21 21 ] of anhydrous chitosan contains two chains having one glucosamine residue in the asymmetric unit with the primary hy...
Article
Full-text available
Alternative hydrogen-bond structures were found for cellulose II and IIII based on molecular dynamics simulations using four force fields and energy optimization based on density functional theory. All the modeling results were in support to the new hydrogen-bonding network. The revised structures of cellulose II and IIII differ with the fiber diff...
Article
Full-text available
The influence of the non-bonded parameters, i. e., Lennard-Jones and the partial atomic charges, on the predicted unit cell dimensions of different allomorphs of cellulose were studied in the framework of the GROMOS force field. Systematic variation of partial atomic charges revealed the particular importance of charge distribution at the proximity...
Article
Full-text available
A protocol was developed to freeze-trap (at 150 K) cellulose as it is undergoing liquid ammonia pretreatment, and then to collect X-ray diffraction data from the freeze-trapped reactants as the reaction is allowed to proceed and ammonia is allowed to melt and then evaporate, leaving ammonia-cellulose I. Cellulose adopts a new two-chain crystal form...