Can Ultrasonic Spectroscopy Measure the Size of Nanoparticles?

High-frequency ultrasound attenuation spectroscopy (abbreviated as ultrasound spectroscopy) is a new method for measuring the particle size of nanoparticles in recent years. Due to the strong penetrating power of ultrasound, this method is especially suitable for the me assurement of high-concentration nanoparticles. its rationale Yes: When ultrasonic waves of different frequencies propagate in the nanoparticle suspension, the attenuation of different frequency ultrasonic waves by nanoparticles The attenuation is different, and the figure shows the theoretical attenuation characteristics with frequency for diff erent size nanoparticles. according to The ultrasonic attenuation spectrum characteristics of nanoparticles, after measuring the ultrasonic attenuation spectrum of nanoparticles, using the simplified ECAH (Epstein-Carharts-Allegra-Hawley) model or McClements (David JMcClements )&BLBL(Bouguer-Lambert-Beer-Law) model to process the signal, we can get to the particle size distribution of nanoparticles. At present, the method can measure the minimum when the ultrasonic center frequency is 50MHz when the particle size is 5nm, the mass concentration can reach 40%.

Ultrasonic attenuation spectroscopy to measure nanoparticles is not sensitive to a small amount of large-size impurity particles mixed into the sample to be tested, however, it is very sensitive to the air bubbles in the sample cell, and it is required to eliminate the the air bubbles in the sample to be measured during measurement