First studies on the influence of methylated β-cyclodextrin on the rheological behavior of 1-ethyl-3-methyl imidazolium acetate.
The rheology of solutions of randomly methylated (1.8) β-cyclodextrin (β-CD) in 1-ethyl-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 β-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 β-CD solutions, a non-Newtonian flow behavior including shear thinning was obtained. The influence of temperature and β-CD concentration on the flow behavior was studied for all solutions, and the flow activation energies were calculated from the logarithmic form of the Arrhenius equation for nonassociating electrolytes.
Gonsior
Nina
N
Lehrstuhl für Präparative Polymerchemie, Institut für Organische Chemie und Makromolekulare Chemie, Heinrich-Heine-Universität Düsseldorf, Universitätsstrasse 1, 40225 Düsseldorf, Germany.
Hetzer
Martin
M
Kulicke
Werner-Michael
WM
Ritter
Helmut
H
D005782:Gels / Q000737:chemistry; D007093:Imidazoles / Q000737:chemistry*; D012212:Rheology; D012399:Rotation; D012996:Solutions / Q000737:chemistry; D013696:Temperature; D013816:Thermodynamics; D047392:beta-Cyclodextrins / Q000737:chemistry*
D005782:Gels; D007093:Imidazoles; D012996:Solutions; D047392:beta-Cyclodextrins; C031215:betadex; C518739:1-ethyl-3-methylimidazolium