ひも状ミセル水溶液中でのせん断波の伝播速度と減衰特性

(液体濃度および対イオンモル比の影響)

抄録

Shear wave speeds of aqueous wormlike micellar solutions of cetyltrimethylammonium bromide (CTAB) and sodium salicylate (NaSal) were measured in a surfactant concentration range of 2-50 mM at different counterion to surfactant concentration ratios. Shear waves were excited by the impulsive motion of a flat plate driven by a solenoid-based actuator, and were visualized by using a circular polariscope and a CCD camera. The shear wave speed was determined by tracking the position of a light intensity peak over several frames. Shear wave speeds were found to strongly depend on the surfactant concentration rather than on counterion to surfactant ratios, and were found to increase proportionally to the surfactant concentration in this concentration range. The attenuation factor of the exponential decay of the wave front was not obtained because the stress jump across the wave front was smoothed significantly.