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Self-assembly of colloidal particles due to elastic interactions in nematic liquid crystals promises tunable composite materials and can be guided by exploiting surface functionalization, geometric shape and topology, though these means of controlling self-assembly remain limited. Here, we realize low-symmetry achiral and chiral elastic colloids in the nematic liquid crystals using colloidal polygonal concave and convex prisms. We show that the controlled pinning of disclinations at the prism edges alters the symmetry of director distortions around the prisms and their orientation with respect to the far-field director. The controlled localization of the disclinations at the prism's edges significantly influences the anisotropy of the diffusion properties of prisms dispersed in liquid crystals and allows one to modify their self-assembly. We show that elastic interactions between polygonal prisms can be switched between repulsive and attractive just by controlled re-pinning the disclinations at different edges using laser tweezers. Our findings demonstrate that elastic interactions between colloidal particles dispersed in nematic liquid crystals are sensitive to the topologically equivalent but geometrically rich controlled configurations of the particle-induced defects.
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Directing and reconfiguring colloidal assembly by disclination networks in nematic liquid crystal as templates
Exotic structures with interesting physical and chemical properties can be achieved by self-organizing engineered building blocks. The central aim for self-assembly is to precisely control the position and orientation of individual building blocks. In this work, we use topological defects (disclinations) in nematic liquid crystals as templates to direct the self-assembly of colloidal particles into designable 3D structures. By photopatterning preprogrammed molecular orientations at two confining surfaces, we created pre-designable disclination networks and characterized their interactions with spherical colloidal particles. We find that colloidal particles are attracted to different disclinations depending on the orientation of the point defect (elastic dipole) around the colloids. We demonstrate that the positions, network structures, and orientation of the elastic dipoles of the colloidal chains can be pre-designed and reconfigured with remote illumination of polarized light.
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- PAR ID:
- 10509686
- Publisher / Repository:
- Elsevier
- Date Published:
- Journal Name:
- Giant
- Volume:
- 17
- Issue:
- C
- ISSN:
- 2666-5425
- Page Range / eLocation ID:
- 100228
- Subject(s) / Keyword(s):
- Topological defects Self-assembly Photopatterning Optical reconfiguration
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
-
Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.giant.2023.100228
