Ultrasonic absorption and velocity measurements for poly (vinyl alcohol) and water solutions

Abstract

The ultrasonic absorption and velocity at 21 MHz and also the shear viscosity were measured for poly (vinyl alcohol) and water solutions. The concentrations of poly (vinyl alcohol) by weight that were used were 1%, 3%, 5%, 9%. Measurements were made at 25 ø, 30 ø, 35 ø, 40 ø, and 45 øC. It was found that a/f 2 decreased with increasing temperature and increased with increasing concentration.The wave velocity increased with both temperature and concentration. The shear viscosity was observed to decrease with temperature and increase with concentration.

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.…”

Temperature dependence of the viscoelastic properties of a natural gastropod mucus by Brillouin light scattering spectroscopy

“…Rates of decrease and velocities intermediate to those of water and snail mucus are observed for several aqueous polymer solutions with polymer concentrations similar to the glycoprotein concentration in the mucus over the temperature range 20 °C to 45 °C. 28–34…”

“…The observed decrease with increasing temperature is similar to that previously reported for water 37 and other aqueous polymer solutions. 29–33…”

“…Rates of decrease and velocities intermediate to those of water and snail mucus are observed for several aqueous polymer solutions with polymer concentrations similar to the glycoprotein concentration in the mucus over the temperature range 20 1C to 45 1C. [28][29][30][31][32][33][34] For À2.5 1C Z T Z À11 1C, the mucus hypersound velocity displays an overall increase at a decreasing rate from its minimum value of B1570 m s À1 at T pt = À2.5 1C to B1700 m s À1 at À11.0 1C. This behaviour contrasts with that for supercooled water for which the velocity is B10-30% lower and which exhibits a rapid monotonic decrease with temperature over this range.…”

“…The observed decrease with increasing temperature is similar to that previously reported for water 37 and other aqueous polymer solutions. [29][30][31][32][33] Fig. 6 shows the natural logarithm of the apparent viscosity as a function of inverse temperature for snail mucus.…”