Nanoparticle-laden droplets of liquid crystals: Interactive morphogenesis and dynamic assembly

• Published in: Science advances Vol. 5; no. 7; p. eaav1035
• Main Authors: Li, Yunfeng, Khuu, Nancy, Prince, Elisabeth, Alizadehgiashi, Moien, Galati, Elizabeth, Lavrentovich, Oleg D, Kumacheva, Eugenia
• Format: Journal Article
• Language: English
• Published: United States American Association for the Advancement of Science 01.07.2019
• Subjects: Chemical Physics; Materials Science; Physics; SciAdv r-articles
• ISSN: 2375-2548; 2375-2548
• DOI: 10.1126/sciadv.aav1035

Defects in liquid crystals serve as templates for nanoparticle (NP) organization; however, NP assembly in cholesteric (Ch) liquid crystals is only beginning to emerge. We show interactive morphogenesis of NP assemblies and a Ch liquid crystalline host formed by cellulose nanocrystals (CNCs), in which both the host and the guest experience marked changes in shape and structure as a function of concentration. At low NP loading, Ch-CNC droplets exhibit flat-ellipsoidal packing of Ch pseudolayers, while the NPs form a toroidal ring- or two cone-shaped assemblies at droplet poles. Increase in NP loading triggers reversible droplet transformation to gain a core-shell morphology with an isotropic core and a Ch shell, with NPs partitioning in the core and in disclinations. We show programmable assembly of droplets carrying magnetic NPs. This work offers a strategy for NP organization in Ch liquid crystals, thus broadening the spectrum of architectures of soft nanostructured materials.