Berlin 2005 – wissenschaftliches Programm
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AKB: Biologische Physik
AKB 100: Poster Session I
AKB 100.59: Poster
Samstag, 5. März 2005, 16:45–18:45, Poster TU D
Anisotropy of water adsorbed to cellulose fibres — •Ingo Grotkopp1, Klaas Kölln1, Stefan Janssen2, and martin Müller1 — 1Institut für Experimentelle und Angewandte Physik, Christian-Albrechts-Universität zu Kiel — 2SINQ, Paul-Scherrer-Institut, Villigen, Switzerland
Many unique features of water in plant cell walls have been reported over the last decades. Water adsorbed to the disordered regions of cellulose, the main constituent of plant cell walls, exhibits liquid dynamics below 0 ∘C and is therefore termed "non-freezing". The water molecules are thought to be inserted between individual hydrogen bonded cellulose chains, and they do not form crystalline ice networks. Upon cooling, an increasing part of the water molecules freezes in a gradual, heterogeneous glass transition to a new type of amorphous ice. The remainder is supercooled and is liquid down to 200 K with its dynamics being strongly retarded. Inelastic neutron scattering studies on water in oriented cellulose fibres show that the structural and dynamical properties of the water/ice network are anisotropic. This anisotropy allows us to conclude on the arrangement of water molecules in the semi-crystalline cellulose material.