Journal of Physical Chemistry B, Vol.114, No.39, 12468-12472, 2010
First Studies on the Influence of Methylated beta-Cyclodextrin on the Rheological Behavior of 1-Ethyl-3-methyl Imidazolium Acetate
The rheology of solutions of randomly methylated (1.8) beta-cyclodextrin (beta-CD) in 1-ethy1-3-methyl imidazolium acetate ([EMIM][Ac]) was studied in detail by rotational and oscillatory shear measurements. It was found that a gel structure was formed even at a relatively low beta-cD concentration, which induced intriguing results in oscillation experiments. The solutions showed abrupt changes of the structurally dependent rheological moduli and reproducible transitions from gel to sol state at specific shear stress, For all [beta-CD solutions, a non-Newtonian flow behavior including shear thinning was obtained. The influence of temperature and beta-CD concentration on the flow behavior was studied for all solutions, and the How activation energies were calculated from the logarithmic form of the Arrhenius equation for nonassociating electrolytes.