Ultrasonic velocity and absorption measurements in an aqueous solution of poly(sodium 4-styrenesulfonate)

Abstract

Both the ultrasonic velocity at 3 MHz and the absorption coefficient in the frequency range from 0.2 to 2 MHz were measured for aqueous solutions of poly(sodium 4-styrenesulfonate) over the concentration range from 5 to 25% (by weight). The pulse echo overlap method was employed to measure the ultrasonic velocity over the temperature range from 10 to 90 o C; the high-Q ultrasonic resonator method was used for the measurement of the absorption coefficient at 20 o C. The velocities exhibited their maximum values at ca. 55, 59, 63, 67, and 71 o C for the 25, 20, 15, 10, and 5% solutions, respectively. The velocity increased with respect to the poly(sodium 4-styrenesulfonate) concentration at a given temperature. A study of the concentration dependence of the both the relaxation frequency and amplitude indicated that the relaxation at ca. 200 kHz is related to structural fluctuations of the polymer molecules, such as the segmental motions of the polymer chains and that the relaxation at ca. 1 MHz resulted from the proton transfer reactions of the oxygen sites of SO 3 . Both the absorption and the shear viscosity increase upon increasing the polymer concentration, but they decrease upon increasing the temperature.

Effect of ultrasound on the aqueous viscosity of several water-soluble polymers

“…It was reported that ultrasonic adsorption to polymeric medium was evaluated by absorption coefficients, sound velocities and viscosity, for different nonionic and ionic polymer solutions, such as polyethylene glycol (PEG), polyvinyl alcohol (PVA) and PAA, at high frequencies of 2-130 MHz. [14][15][16][17][18] However, no results for US using lower frequencies have been reported.…”

Ultrasonic velocity measurements in liquids with high resolution—techniques, selected applications and perspectives

“…Due to the obtained measurement quality, pushing the resolution of current ultrasonic velocimeters to 10 −7 , such measurements are used more and more often, not only for fundamental studies in physical chemistry [12][13][14][15][16][17][18], biophysics and biochemistry [19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34][35], but also for numerous technical applications, e.g. in chemical engineering.…”