Novel approach to the dispersion of nano-sized particles with shock wave in liquid

Abstract

By now, nano technologies have been limited because of the dispersion of nano-sized particles. Due to the high surface energy and strong adsorptive states of nano-materials, a standing interest is observed in the study of high-energy method of dispersion. In this paper, shock wave, which is based on the high intensity of focused ultrasound (HIFU) technology, is successfully introduced to distribute and disperse nano-sized particles. Since the power density in the focused zone is up to 100 W/mm2, the frequency of ultrasound is close to 1 MHz, and energy of shock wave is controllable, strong micro scale transient cavitations and acoustic streaming are dedicated to solve the problem of conglomeration. Therefore, three kinds of nano-materials, i.e., nano SiO2, montmorillonite (MMT) and carbon nanotube (CNT), which is a representative collection of different dimensions nano-sized particles, are dispersed in different liquid phase respectively by this method. Compared with the normal ultrasonic treatment, the dispersion stability and efficiency are remarkably improved, which are measured by absorption spectrometer, transmission electron microscopy (TEM) and the X-ray diffraction (XRD). It is demonstrated that ogano-MMT might be dispersed with no changes and the origin length of CNT could not be trimmed with good dispersion.