(418r) Synthesis and Assembly of Anisotropic Particles
AIChE Annual Meeting
Tuesday, October 18, 2011 - 6:00pm to 8:00pm
Due to the presence of anisotropy in the physical properties, chemical compositions, surface functionalities, or geometric shapes, anisotropic particles can assemble via directional interactions, forming large numbers of superstructures with novel collective properties that are not manifested in single particle or in bulk material. As such, anisotropic particles are excellent candidates for more than molecular models and have broad ranges of industrial-level applications.
Here, we present our synthetic strategies to make one particular kind of anisotropic particles: colloidal dimers. By combination of phase separation, elastic contraction/expansion, and surface coating, we have made a variety of colloidal dimers with different characteristics, such as (1) homogeneous dimers with identical chemical composition but different sizes on each lobe; (2) heterogeneous dimers with different surface functionalities on each lobe; (3) heterogeneous dimers with different chemical compositions on each lobe; and (4) heterogeneous dimers with opposite signs of charges on each lobe. The precise control of (physical, chemical, geometrical) anisotropy on colloidal dimers allows us to study the self- and guided assembly of colloidal dimers systematically. We will also demonstrate intriguing results of assembling those anisotropic particles under different external fields, such as the electric field and convective flow field. Rich phase behaviors and transient states will be presented.