Wet Electrostatic Assembly for Granule Fabrication and Composite Microstructure Design

Ceramic materials are indispensable for high-temperature structural applications because of their high melting points and excellent thermal stability. Owing to the difficulty of melt-processing, most ceramics are fabricated via powder metallurgy. Although the increasing availability of nanosized powders has enabled reduced sintering temperatures and enhanced properties through nanocomposite design, powder refinement also introduces critical challenges, such as poor handling during forming and difficulty in achieving uniform mixing of dissimilar particles. In addition, conventional mechanical mixing generally produces only uniformly dispersed microstructures, restricting the development of anisotropic or hierarchical architectures. This review summarizes recent progress in electrostatic assembly of ceramic particles as a wet-processing strategy. By controlling particle surface charge via polyelectrolyte adsorption and Layer-by-Layer modification, oppositely charged particles can be assembled into composite particles or spherical, monodisperse composite granules. These granules exhibit high flowability and packing ability, significantly improving processability while eliminating the need for mechanical mixing. Furthermore, the use of designed composite and core-shell granules enables microstructure control from the nanoscale to the macroscale, including the formation of three-dimensionally interconnected functional layers. Electrostatic assembly thus provides a versatile platform for advanced ceramic composite design beyond the capabilities of conventional powder metallurgy routes.