Activités scientifiques :
Structure and physical properties of crystalline polysaccharide. Cellulose, chitin/chitosan, amylose/starch are the most abundant biopolymer on earth and share the particularity of forming crystal structure and supramolecular morphology governed by the biological process. Their physical properties and chemical susceptibilities are closely related to its unique structure that cannot be achieved in an industrial process. My research is focused on the elucidation of the static structure and the understanding of structure â€“ property relationships.
1. Crystal structures
Experimental determination of crystal structures is the basis of the understanding of inter-molecular interactions and conformational freedom of the molecules. In the absence of an established method to grow macroscopic crystal of polysaccharides, my main approach consist of preparing oriented polycrystalline sample composed of good diffracting elements. A series of structures was determined using X-ray and neutron fiber diffraction techniques, and many other structures are being analyzed. The diffraction study is being done in close collaboration with Professor Wada of the University of Tokyo, Dr. Langan of the Los Alamos National Laboratories and Trevor Forsyth whereas complemetary techniques such as Solid state NMR and Electron Microscopy are done in our team by Dr. Heux and Dr. Putaux respectively.
- Nishiyama, Y.; Johnson, G. P.; French, A. D.; Forsyth, V. T. & Langan, P. (2008), 'Neutron crystallography, molecular dynamics, and quantum mechanics studies of the nature of hydrogen bonding in cellulose I-β', Biomacromolecules 9(11), 3133-3140.
- Cardoso, M. B.; Putaux, J. L.; Nishiyama, Y.; Helbert, W.; Hytch, M.; Silveira, N. P. & Chanzy, H. (2007), 'Single crystals of V-amylose complexed with α-naphthol', Biomacromolecules 8(4), 1319-1326.
- Wada, M.; Nishiyama, Y. & Langan, P. (2006), 'X-ray structure of ammonia-cellulose I: New insights into the conversion of cellulose I to cellulose III', Macromolecules 39(8), 2947-2952.
- Langan, P.; Sukumar, N.; Nishiyama, Y. & Chanzy, H. (2005), 'Synchrotron X-ray structures of cellulose I-β and regenerated cellulose II at ambient temperature and 100 K', Cellulose 12(6), 551-562.
- Wada, M.; Chanzy, H.; Nishiyama, Y. & Langan, P. (2004), 'Cellulose III_I crystal structure and hydrogen bonding by synchrotron X-ray and neutron fiber diffraction', Macromolecules 37(23), 8548-8555.
- Nishiyama, Y.; Sugiyama, J.; Chanzy, H. & Langan, P. (2003), 'Crystal structure and hydrogen bonding system in cellulose 1(alpha), from synchrotron X-ray and neutron fiber diffraction', J.
Am. Chem. Soc. 125(47), 14300-14306.
- Nishiyama, Y.; Langan, P. & Chanzy, H. (2002), 'Crystal structure and hydrogen-bonding system in cellulose 1 β from synchrotron X-ray and neutron fiber diffraction', J. Am. Chem. Soc. 124(31), 9074-9082.
- Langan, P.; Nishiyama, Y. & Chanzy, H. (2001), 'X-ray structure of mercerized cellulose II at 1 angstrom resolution', Biomacromolecules 2(2), 410-416.
- Langan, P.; Nishiyama, Y. & Chanzy, H. (1999), 'A revised structure and hydrogen-bonding system in cellulose II from a neutron fiber diffraction analysis', J.
Am. Chem. Soc. 121(43), 9940-9946.
- Wada, M.; Kwon, G. J. & Nishiyama, Y. (2008), 'Structure and thermal behavior of a cellulose I-ethylenediamine complex', Biomacromolecules 9(10), 2898-2904.
- Noishiki, Y.; Nishiyama, Y.; Wada, M. & Kuga, S. (2005), 'Complexation of α-chitin with aliphatic amines', Biomacromolecules 6(4), 2362-2364.
- Noishiki, Y.; Kuga, S.; Wada, M.; Hori, I. & Nishiyama, Y. (2004), 'Guest selectivity in complexation of β-chitin', Macromolecules 37(18), 6839-6842.
2. Morphology, Surface, Suspensions
At higher length scale, native cellulose and chitin form microfibrillar structure with rather well defined boundary. The small lateral sizes result in high specific surface where chemical reactions (including enzyme catalized reactions can take place. The preparation of model sample sometimes also involve some chemical modification of the surface to facilitate processing or isolation of microfibrils, in most cases are suspension in water or other solvents.
- Lasseuguette, E.; Roux, D. & Nishiyama, Y. (2008), 'Rheological properties of microfibrillar suspension of TEMPO-oxidized pulp', Cellulose 15(3), 425-433.
- Saito, T.; Kimura, S.; Nishiyama, Y. & Isogai, A. (2007), 'Cellulose nanofibers prepared by TEMPO-mediated oxidation of native cellulose', Biomacromolecules 8(8), 2485-2491.
- Saito, T.; Nishiyama, Y.; Putaux, J. L.; Vignon, M. & Isogai, A. (2006), 'Homogeneous suspensions of individualized microfibrils from TEMPO-catalyzed oxidation of native cellulose', Biomacromolecules 7(6), 1687-1691.
- Yuan, H. H.; Nishiyama, Y.; Wada, M. & Kuga, S. (2006), 'Surface acylation of cellulose whiskers by drying aqueous emulsion', Biomacromolecules 7(3), 696-700.
- Yuan, H. H.; Nishiyama, Y. & Kuga, S. (2005), 'Surface esterification of cellulose by vapor-phase treatment with trifluoroacetic anhydride', Cellulose 12(5), 543-549.
- Kim, D. Y.; Nishiyama, Y. & Kuga, S. (2002), 'Surface acetylation of bacterial cellulose', Cellulose 9(3-4), 361-367.
- Muller, M.; Czihak, C.; Schober, H.; Nishiyama, Y. & Vogl, G. (2000), 'All disordered regions of native cellulose show common low-frequency dynamics', Macromolecules 33(5), 1834-1840.
- Helbert, W.; Nishiyama, Y.; Okano, T. & Sugiyama, J. (1998), 'Molecular imaging of Halocynthia papillosa cellulose', J. Struct. Biol. 124(1), 42-50.
- Nishiyama, Y.; Kuga, S.; Wada, M. & Okano, T. (1997), 'Cellulose microcrystal film of high uniaxial orientation', Macromolecules 30(20), 6395-6397.
There are also domains where the molecules are strained and are more susceptible to hydrolysis, which is the basis of preparation of crystalline particles. Those structure and morphologies are analyzed by combining many different complementary techniques.
- Elazzouzi-Hafraoui, S.; Nishiyama, Y.; Putaux, J. L.; Heux, L.; Dubreuil, F. & Rochas, C. (2008), 'The shape and size distribution of crystalline nanoparticles prepared by acid hydrolysis of native cellulose', Biomacromolecules 9(1), 57-65.
- Nishiyama, Y.; Kim, U. J.; Kim, D. Y.; Katsumata, K. S.; May, R. P. & Langan, P. (2003), 'Periodic disorder along ramie cellulose microfibrils', Biomacromolecules 4(4), 1013-1017.
3. Physical properties of crystals
I am currently driving a research project financed by Agence National de Recherche (ANR) entitled
"Load transfer in materials based on nanometric polysaccharide crystals" with Dr. Jean, Dr. Molina-Boisseau,
Dr. Dubreuil and Dr. Lancelon in collaboration with Prof. Wada of the university of Tokyo and Prof. Müller of
the Kiel University and GKSS institute. It involves to study the physical properties such as elastic tensors
and thermal expansion tensors of the crystals.
Liste complète des publications