title: Dynamic light scattering of xanthan gum biopolymer in colloidal dispersion.
abstract: The dynamical properties of nanogels of xanthan gum (XG) with hydrodynamic radius controlled in a size range from 5 nm to 35 nm, were studied at the different XG concentrations in water/sodium bis-2-ethylhexyl-sulfosuccinate (AOT)/decane reverse micelles (RMs) vs. mass fraction of nano-droplet (MFD) at W = 40, using dynamic light scattering (DLS). The diffusion study of nanometer-sized droplets by DLS technique indicated that enhancing concentration of the XG polysaccharide resulted in exchanging the attractive interaction between nano-gels to repulsive interaction, as the mass fraction of nano-droplets increased. The reorientation time (τr ) of water nanodroplets decreased with MFD for water-in-oil AOT micro-emulsion comprising high concentration (0.0000625) of XG. On the other hand, decreasing concentration of biopolymer led to increasing the rotational correlation time of water nanodroplets with MFD. In conclusion, a single relaxation curve was observed for AOT inverse microemulsions containing different XG concentrations. Furthermore, the interaction between nanogels was changed from attractive to repulsive versus concentration of XG in the AOT RMs.
authors.affiliation: Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, P.O. Box 87317-51167, Islamic Republic of Iran; Department of Physics, University of Zabol, Zabol, P.O. Box 35856-98613, Islamic Republic of Iran.
authors.forename: Abbas
authors.initials: A
authors.lastname: Rahdar
authors.affiliation: Institute of Nanoscience and Nanotechnology, University of Kashan, Kashan, P.O. Box 87317-51167, Islamic Republic of Iran; Department of Physics, University of Kashan, Kashan, P.O. Box 87317-51167, Islamic Republic of Iran.
authors.forename: Mohammad
authors.initials: M
authors.lastname: Almasi-Kashi
keywords: Dynamic light scattering; Interaction; Mass fraction of droplet; Microemulsion; Nano-droplets; Xanthan gum