Austin JC, Challis RE
Ultrasonics and Digital Signal Processing Laboratory, Keele University, Keele, Staffordshire, ST5 5BG, United Kingdom
J Colloid Interface Sci. 1998 Oct 1;206(1):146-157. doi: 10.1006/jcis.1998.5712.
A broadband ultrasonic spectrometer has been used to measure ultrasonic attenuation and phase velocity dispersion as functions of frequency in kaolin suspensions over a range of solid volume fractions from phi = 0.01 to phi = 0.08 and over a pH range from 3 to 9. The Harker and Temple theory was used to simulate ultrasound propagation in the suspension, using measured slope viscosity, particle size, and size distribution. Simulated results for ultrasonic attenuation and phase velocity agree well with measured values. Both sets of results agree well and show that for volume fractions above phi approximately 0.05 attenuation and velocity dispersion increase for increasing floc size, whereas for volume fractions below phi approximately 0.05 attenuation and velocity dispersion both decrease. It is proposed that the mechanism for this change in behavior around phi approximately 0.05 involves changes in floc density and floc size distribution with phi and pH. Copyright 1998 Academic Press.
一种宽带超声光谱仪已被用于测量高岭土悬浮液在一系列固体体积分数（从φ = 0.01至φ = 0.08）以及pH范围从3至9内，超声衰减和相速度色散随频率的变化情况。利用测得的斜率粘度、颗粒尺寸和尺寸分布，采用哈克和坦普尔理论来模拟超声在悬浮液中的传播。超声衰减和相速度的模拟结果与测量值吻合良好。两组结果都吻合得很好，并且表明对于体积分数高于约0.05的情况，随着絮凝体尺寸的增加，衰减和速度色散增大；而对于体积分数低于约0.05的情况，衰减和速度色散都减小。有人提出，在φ约为0.05附近这种行为变化的机制涉及絮凝体密度和絮凝体尺寸分布随φ和pH的变化。版权所有1998年学术出版社。
