Particlesolids

Particlesolids are solids composed predominantly of discrete particles, such as grains, microparticles, or nanoparticles, that come together to form a solid phase through interparticle forces, welding, or mechanical consolidation. In this view, the fundamental constituents retain some individuality rather than forming a single, continuous atomic lattice. Particlesolids encompass granular media, powder compacts, and assemblies of nanoparticles that achieve solid behavior through packing, binding, or sintering.

The microstructure of a particlesolid is defined by particle size distribution, shapes, surface chemistry, and the way particles contact and interlock with each other. Porosity, tortuosity, and coordination number play major roles in transport properties. Mechanical response often reflects contact mechanics and packing density rather than crystal lattice stiffness, leading to behaviors such as yield under shear, jamming transitions, and strong sensitivity to moisture or fines. Thermal and electrical conductivities depend on interparticle contacts and the formation of continuous pathways.

Formation and processing methods vary widely, including milling and grinding to generate powders, precipitation to form micro- or nano-particles, spray drying to create granules, and compaction or tape casting to produce dense or porous solids. Sintering or binding may join particles into a coherent material, while preserving or transforming the original particulate structure.

Applications span catalysts and catalyst supports, pharmaceutical powders and granular tablets, ceramic and metal composite powders, battery and supercapacitor electrodes, filtration media, and additive manufacturing feedstocks. Characterization typically uses particle size analysis, porosity measurements, microscopy (SEM/TEM), surface area assays, and transport or mechanical tests to relate microstructure to bulk properties.