Uniform Nonspherical Colloidal Particles with Tunable ShapesC

摘要

Colloidal particles are ubiquitous for a broad spectrum of applications. Many current applications require nonspherical particles. They have been used for modifying optical properties'11 and as a building block for self-assembled biomateri-als. They are also beneficial for controlling suspension rheology and for engineering colloidal composites. In general, synthesizing uniform nonspherical particles is difficult because surface tension favors spherical shapes in overall length scales. This limitation may be overcome with advanced techniques such as microfluidics and clusterization separations; these precision processes generally produce small yields, severely limiting their utility for practical applications. Recently, several methods that can produce nonspherical particles such as dimers and higher-order clusters have produced larger yields. These methods all rely on random coagulation of single particles or on the formation of clusters by using emulsification techniques. However, a common limitation of these synthesis techniques is that a single batch contains many particle types, requiring a sorting process to produce homogeneous samples, thus limiting the yield for any given sample type. Thus, there exists a need for flexible and robust techniques to generate nonspherical particles with well-defined shapes and high yields.