Nanocrystal Self-Assembly Assisted by Oriented Attachment

摘要

Nanoparticles with a spectrum of sizes, shapes, mass distributions (e.g. hollow, rattle-type, core-shell particles), and compositions are today routinely synthesized by a growing set of techniques involving "wet chemistry": sol-gel, solvothermal, ionothermal, and soft- and hard-templating approaches, to name a few.The self- and/or directed assembly of these nanoscale building blocks into purposeful, organized superstructures with complex symmetries and tunable functionality and properties is attractive for a host of existing and emerging applications in biomedical diagnostics and sensing, electrical-energy storage, nanocomputing, optoelectronics, photonics, photovoltaics, and gas purification. The spontaneous assembly of nanostructures is also of fundamental scientific interest, as it offers uncountable possibilities for the creation of metamaterials with properties that rival those accessible from the assembly of atomic building blocks.It also enables direct exploration of the interplay between all of the fundamental forces in condensed matter. Over the last decade, a torrent of new results from experiments, as well as molecular-dynamics and Monte Carlo computer simulations of repulsive or weakly attractive particles,have justified this interest by confirming that easy-to-control variables, such as particle shape, magnetization, symmetry, surface chemistry, and the concentration of depletants, can be used to independently manipulate the range and magnitude of interparticle forces that control assembly. Recent results from the epitaxial growth of films even suggest that upon minor changes, rules that govern the kinetics of the assembly of atoms may be applicable to colloidal and nanoparticle building blocks.