title: Controlling Chirality of Entropic Crystals.
abstract: 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.
authors.affiliation: Applied Physics Program, University of Michigan, Ann Arbor, Michigan 48109, USA.|Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Pablo F
authors.initials: PF
authors.lastname: Damasceno
authors.affiliation: Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, USA.|Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Andrew S
authors.initials: AS
authors.lastname: Karas
authors.affiliation: Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, USA.|Department of Physics, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Benjamin A
authors.initials: BA
authors.lastname: Schultz
authors.affiliation: Biointerfaces Institute, University of Michigan, Ann Arbor, Michigan 48109, USA.|Department of Chemical Engineering, University of Michigan, Ann Arbor, Michigan 48109, USA.
authors.forename: Michael
authors.initials: M
authors.lastname: Engel
authors.affiliation: 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.
authors.forename: Sharon C
authors.initials: SC
authors.lastname: Glotzer
mesh_terms: D003102:Colloids / Q000737:chemistry*; D003460:Crystallization; D019277:Entropy; D008956:Models, Chemical; D009010:Monte Carlo Method; D013237:Stereoisomerism
chemical_list: D003102:Colloids