Experimental study and simulation on the formation of two-dimensional particle arrangements

The microscopic processes and mechanisms were examined for the formation of two-dimensional close-packed arrays of SiO2-microparticles in its colloidal suspension. An experimental device was designed to make two-dimensional arrays of colloidal particles by sandwiching the particles under various compressive loads between two of solid bars. It was found that a specific loading configuration yielded the most sufficient result for successfully forming a closest packed array over its large area. The experimental technique proposed in this study provides an efficient tool for eliminating several types of defects undesirably induced and included in the processes for forming particulate aggregates with close-packed structures. The microscopic processes of the formation of two-dimensionally ordered aggregates were also examined using the discrete element method (DEM). The DEM simulation suggested useful engineering information on the fabrication of close-packed structures of particles.