A6.2 Molecular Assembly
Nanoparticles can be made from larger particles and reducing their size via cutting, etching or machining– this is called “top down” molecular assembly. Silicon crystals, common these days in electronic devices, are manipulated in this way to make “computer chips”.
“Bottom-up” molecular assembly works the other way around, where the nanoparticles are built up from smaller particles.
Physical and chemical methods can both be used to assemble atoms into nanoparticles.