Physical substances with at least one characteristic dimension between 1-150 nm can be defined as nanomaterials. Nanomaterials properties can differ from those of the same materials with micron- or mm-scale dimensions. Nanomaterials are the building blocks of practical nanotechnology and can be physically and chemically manipulated for specific applications.

Sigma-Aldrich® offers a wide variety of inorganic and organic nanomaterials, grouped below by chemical class. Note that inorganic nanoparticles (nanopowders and nanoparticle dispersions) are listed in two ways. Nanopowders and nanoparticle dispersions section includes all available nanoparticles grouped by the primary element of their composition. These materials can also be browsed by chemical class in the metals, ceramics, and surface functionalized nanoparticles sections; here individual products are listed alphabetically.