Study on the dispersion behaviors of binary micro/nanoparticles in concentrated suspensions by ultrasonic attenuation technology

摘要

Abstract In this paper, ultrasonic attenuation and electroacoustic techniques are proposed to study the dispersion behaviors and properties of binary particles in high-concentration suspension, to provide an effective characterization method for the design, preparation, and application of complex suspensions with nano- and microparticles. Both suspensions with binary and identical particles were prepared, with submicron cerium oxide (CeO2) particles and micron carbonyl iron powder (CIP) particles, respectively. The particle size distribution (PSD) in suspensions with binary particles was analyzed based on ultrasonic attenuation spectra with different models, and their zeta potential was analyzed based on electroacoustic measurements with different models too. The results showed that the zeta potential signs of CeO2 and CIP particles in suspensions with identical particles were opposite, and the pH value, zeta potential, and dispersion state of CeO2 and CIP particles changed significantly after mixing. The PSD and zeta potential of the binary particles obtained from the effective medium model had large deviations. The binary phase model can obtain accurate zeta potential of binary particles in suspensions, but it obtained PSD of binary particles with some deviation due to agglomeration. The equivalent volume model was brought forward to analyze the actual state of these particles with small density contrast. In these suspensions, the binary particles could be dispersed more efficiently than those in suspensions with identical particles, although there still did exist some agglomerates in the binary suspensions. These results provide a new technique and method for studying the behavior and properties of binary particles in high-concentration complex suspensions.Graphical abstract