title: Scattering investigation of multiscale organization in aqueous solutions of native xanthan.
abstract: The hierarchical morphology of xanthan solutions is analyzed by light and neutron scattering in a broad range of concentrations in order to connect their morphology to their well-documented dynamic properties. Static light scattering inside the semidilute regime is dominated by the form factor of individual xanthan chains while at higher concentrations chain interconnections appear to modify the low wave vector scattering. Dynamic light scattering reveals the self-similar nature of the solutions caused by interchain associations as intensity autocorrelation functions present power-law behaviour. Small angle neutron scattering is dominated by the fractal scattering from the formed network at intermediate length scales. At small length scales the rigid structure of xanthan is revealed and the molecular weight per unit length is extracted. No detectable morphological alterations for shear rates up to 1000rad/s are observed revealing that the shear thinning behaviour of xanthan is related to the disruption of chain-chain associations.
authors: Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 116 35 Athens, Greece. Electronic address: apapagiannopoulos@eie.gr.
authors: Aristeidis
authors: A
authors: Papagiannopoulos
authors: Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, 48 Vassileos Constantinou Avenue, 116 35 Athens, Greece. Electronic address: kwstas_sw@hotmail.com.
authors: Konstantinos
authors: K
authors: Sotiropoulos
authors: Jülich Centre for Neutron Science JCNS, Forschungszentrum Jülich GmbH, Outstation at Heinz Maier-Leibnitz Zentrum (MLZ), 1 Lichtenbergstraße, 85747 Garching, Germany. Electronic address: a.radulescu@fz-juelich.de.
authors: Aurel
authors: A
authors: Radulescu
keywords: Fractal; Helix; Light scattering; Polysaccharide; Small angle neutron scattering; Xanthan