该文以阻抗分析法研究了超声波对石英晶体微天平(QCM)响应特性的影响,结果表明,在超声波存在时QCM的纵波传播与反射受到干扰,QCM的阻抗一频率曲线上出现很多的毛刺干扰波,使QCM的信噪比下降。当采取消除纵波干扰的措施后,毛刺干扰波消失。实验测试了QCM的谐振频率及动态电阻对表面质量负载变化及液体粘度、密度改变的响应,证实超声波对QCM的厚度剪切模式无影响。QCM应用于监测表面活性剂去除油污膜的过程,结果表明在超声波作用下油污膜的去除速率大幅度提高。
The effect of ultrasonic wave on the response of a quartz crystal microbalance (QCM) was investigated by an impedance analysis method. In the presence of ultrasonic wave, the signal-to-noise of QCM in a liquid phase is reduced as burrs are added on its impedance-frequency spectrum. This kind of effect is ascribed to the fact that the reflection condition for the longitudinal wave from QCM is disturbed by ultrasonic wave. The burr noise on the resonant peak of QCM disappears when the longitudinal wave effect is eliminated. The changes in the resonant frequency and motional resistance of QCM were measured under different viscosity and density of liquid phase and the surface mass loading. It is shown that the thickness-shear model of QCM is not influenced by ultrasonic wave effect. The removal of hydrophobic film by non-ionic surfactant were monitored by QCM. The removal is greatly speeded under ultrasonic conditions.