Coagulation Characteristics of Nano-agglomerates in Free Molecular States under Different Electric Field Intensities

10.4209/aaqr.240086

Ting Luo；Pengfei Zhang；Dongxu Cheng；Congcong Li；Junyi Shen；Mingyue Yang；Jie Zhao；Kai Zhang；Qianyuan Yu；Zhandong Shi

Nanoparticle ； Non-spherical ； Dielectric particles ； Coagulation

Aerosol and Air Quality Research

24卷10期（2024 / 10 / 01）

1 - 13

英文

The coagulation behavior of nanoparticles in microfluidic chip channels is complex and affected by various external factors, including electric fields, sound fields, and wakes. Among them, electric fields have been confirmed to be the most effective for combining and manipulating particles to create new materials with diverse functionalities. In this work, the coagulation characteristics of nanoparticles in the electric field were studied, and the feasibility of the simplified Smoluchowski's equation (SE) by Taylor-expansion moment method (TEMOM) when considering non-spherical particle shapes was verified. The results showed that the particle evolution process obtained by introducing fractal dimension was closer to reality. Compared to spherical particles, non-spherical particles are often observed to exhibit potentially stronger coagulation processes, potentially faster aggregation and growth rates, and potentially lower concentrations of surrounding particles. At the same time, due to the increase in collision, coagulation, and fracture times, the dispersed particle system has stronger multi-dispersion, and more new particles of different sizes are formed. Specifically, the concentration of charged non-spherical particles at time τ = 0.5 is about 6.25 times lower than that of charged spherical particles. Similarly, at time τ = 10, the dispersion of charged non-spherical particles is 700 million times greater than that of charged spherical particles. Furthermore, when charged particles with different fractal dimensions are subjected to the same electric field intensity, their coagulation processes exhibit nearly identical behavior. The results of this study are of great significance for guiding the assembly of nanoparticles.