wichita.edu
… as helices, zigzags, belts, or perhaps nanowires with diameter that varies with length. Small-aspect ratio morphologies include spherical, oval, cubic, prism, helical, or pillar. Collections of many particles exist as powders, suspension, or colloids. Phase Compositions Nanoparticles can be composed of a single constituent material or be a composite of…
https://www.wichita.edu/services/environmental_health_and_safety/Nanosafety_manual.php