Yuan Ye, Keller Patrick, Smalyukh Ivan I
Department of Physics, University of Colorado, Boulder, CO 80309, USA.
Soft Matter. 2021 Mar 21;17(11):3037-3046. doi: 10.1039/d0sm02135k. Epub 2021 Jan 25.
Control of physical behaviors of nematic colloids and colloidal crystals has been demonstrated by tuning particle shape, topology, chirality and surface charging. However, the capability of altering physical behaviors of such soft matter systems by changing particle shape and the ensuing responses to external stimuli has remained elusive. We fabricated genus-one nematic elastomeric colloidal ring-shaped particles and various microstructures using two-photon photopolymerization. Nematic ordering within both the nano-printed particle and the surrounding medium leads to anisotropic responses and actuation when heated. With the thermal control, elastomeric microstructures are capable of changing from genus-one to genus-zero surface topology. Using these particles as building blocks, we investigated elastomeric colloidal crystals immersed within a liquid crystal fluid, which exhibit crystallographic symmetry transformations. Our findings may lead to colloidal crystals responsive to a large variety of external stimuli, including electric fields and light. Pre-designed response of elastomeric nematic colloids, including changes of colloidal surface topology and lattice symmetry, are of interest for both fundamental research and applications.
通过调整颗粒形状、拓扑结构、手性和表面电荷，已证明可以控制向列型胶体和胶体晶体的物理行为。然而，通过改变颗粒形状来改变此类软物质系统的物理行为以及随之而来的对外部刺激的响应能力，仍然难以捉摸。我们使用双光子光聚合制备了一类向列型弹性体胶体环形颗粒和各种微观结构。纳米打印颗粒和周围介质中的向列有序导致加热时的各向异性响应和驱动。通过热控制，弹性体微观结构能够从一类表面拓扑结构转变为零类表面拓扑结构。使用这些颗粒作为构建块，我们研究了浸没在液晶流体中的弹性体胶体晶体，其表现出晶体学对称性转变。我们的发现可能会导致对包括电场和光在内的多种外部刺激做出响应的胶体晶体。弹性体向列型胶体的预先设计的响应，包括胶体表面拓扑结构和晶格对称性的变化，对于基础研究和应用都具有重要意义。
