Nanostructured

Nanostructured refers to materials or structures engineered to have features at the nanometer scale. Such features can be grains, pores, coatings, fibers, or particles that collectively create a nanoscale architecture throughout the material. The nanoscale geometry leads to properties that differ from bulk counterparts due to size-dependent phenomena, high surface area, and increased importance of interfaces and defects.

Nanostructured materials can be produced by top-down methods that shrink features, such as milling, lithography, or etching, and by bottom-up methods that assemble atoms or molecules, such as chemical synthesis, self-assembly, or vapor deposition. Hybrid approaches combine both.

Common classes include nanocrystalline metals and alloys, nanoporous ceramics and oxides, polymer nanocomposites, and carbon-based nanostructures such as nanotubes and graphene. Applications span catalysis, energy storage and conversion, sensing, electronics, coatings, and biomedical devices. For example, nanostructured catalysts exploit high surface area and active sites; nanostructured electrodes offer high capacity and fast kinetics; nanostructured coatings can improve wear resistance.

Characterization typically uses electron microscopy (TEM, SEM), atomic force microscopy, X-ray diffraction, and surface area analysis (BET). Synthesis and processing challenges include controlling grain growth, preventing agglomeration, and achieving uniformity at scale. Environmental, health, and safety considerations are also addressed for nanoscale materials.

This concise definition reflects a broad and interdisciplinary field where structure at the nanoscale governs performance and enables new functionalities.