Controlling Chirality of Entropic Crystals

作     者：Pablo F. Damasceno Andrew S. Karas Benjamin A. Schultz Michael Engel Sharon C. Glotzer 

作者机构：Applied Physics Program University of Michigan Ann Arbor Michigan 48109 USA Biointerfaces Institute University of Michigan Ann Arbor Michigan 48109 USA Department of Chemical Engineering University of Michigan Ann Arbor Michigan 48109 USA Department of Physics University of Michigan Ann Arbor Michigan 48109 USA Department of Materials Science and Engineering University of Michigan Ann Arbor Michigan 48109 USA 

出 版 物：《Physical Review Letters》 (Phys Rev Lett)

年 卷 期：2015年第115卷第15期

页      面：158303-158303页

核心收录：

学科分类：07[理学] 0702[理学-物理学] 

基　　金：U.S. Army Research Office [W911NF-10-1-0518] DOD/ASD (RE) [N00244-09-1-0062] National Science Foundation, Division of Materials Research [DMR 1120923] 

主　　题：COLLOIDAL crystals CHIRALITY ENTROPY PHOTONIC crystals MONTE Carlo method 

摘      要：Colloidal crystal structures with complexity and diversity rivaling atomic and molecular crystals have been predicted and obtained for hard particles by entropy maximization. However, thus far homochiral colloidal crystals, which are candidates for photonic metamaterials, are absent. Using Monte Carlo simulations we show that chiral polyhedra exhibiting weak directional entropic forces self-assemble either an achiral crystal or a chiral crystal with limited control over the crystal handedness. Building blocks with stronger faceting exhibit higher selectivity and assemble a chiral crystal with handedness uniquely determined by the particle chirality. Tuning the strength of directional entropic forces by means of particle rounding or the use of depletants allows for reconfiguration between achiral and homochiral crystals. We rationalize our findings by quantifying the chirality strength of each particle, both from particle geometry and potential of mean force and torque diagrams.