Shape Effect in Nanoparticle Self-Assembly

摘要

The assembly of nanoparticles is a key step for their application as nanodevices. Self-assembly of nanomaterials strongly depends on interparticle interactions, particle size distribution and particle shape. Current methods for assembling nanoparticles include capillary force, template-directed patterning, or surface derivatization of particles that modify interparticle interactions. Spontaneous self-assembly of spherical nanoparticles occurs only with particles with a narrow size distribution, that is, those with a polydispersity <5%, and leads to a compact 2D or 3D structure. In contrast, nonspherical nanoparticles show different types of self-assembly. Oriented attachment-based self-assembly and crystallization was observed for inorganic colloids and nanoparticles. Various liquid-crystalline order structures such as nematic, columnar, and smectic phases are observed for rodlike and platelike particles at high volume fractions. Similarly, bundle structures have been observed for nanowires and nanotubes.