Aggregate morphology and flow behaviour of micellar alklyglycoside solutions

摘要

Solutions of n-nonyl-beta-D-glucoside (C_9G_1),n-decyl-beta-D-gluco-side (C_(10)G_1),n-dodecyl-beta-D-malto-side (C_(12)G_2),n-tetradecyl-beta-D-maltoside (C_(14)G_2) and C_9G_1/C_(10)G_1 mixtures have been characterised by capillary viscometry and rheology in H_2O and D_2O,in order to map the influence of surfactant characteristics on micellisation over a wide concentration range.For the maltosides,the micellar solutions are shear thinning with a zero-shear viscosity that scales with concentration according to a power law with an exponent of about 5.8.In contrast,solutions of the glucosides C_9G_1,C_(10)G_1 and their mixtures show Newtonian flow behaviour and a much lower scaling exponent (<2.4).In C_9G_1/C_(10)G_1 mixtures,the scaling exponent decreases monotonously with increasing C_(10)G_1 content.The flow behaviour correlates with the packing requirements of the various surfactants,and are compatible with the idea that the maltosides form worm-like micelles,whereas the glucosides form branched,interconnected micelles (C_9G_1) and spacefilling micellar networks (C_(10)G_1).