Compound droplets derived from a cholesteric suspension of cellulose nanocrystals. Issue 47 (23rd November 2018)

• Record Type: Journal Article
• Authors: Suzuki, Toyoko; Li, Yunfeng; Gevorkian, Albert; Kumacheva, Eugenia
• Is Part Of: Soft matter. Volume 14:Issue 47(2018)
• Page Start: 9713
• Page End: 9719
• Publication Date: 2018-11-23
• Subjects: Soft condensed matter -- Periodicals; 530.413
• DOI: 10.1039/c8sm01716f
• Languages: English
• ISSNs: 1744-683X

Abstract

Abstract : Compound Janus droplets were generated using microfluidic emulsification of the cholesteric suspension of cellulose nanocrystals and mineral oil. The capability to fine-tune droplet composition and the shape of the cholesteric phase is shown. The droplets were used to generate cholesteric microgels with non-conventional shapes. Abstract : This study reports microfluidic generation of Janus droplets that consist of a liquid crystal component (a cholesteric aqueous suspension of cellulose nanocrystals, Ch-CNC) and a mineral oil (MO) component. The composition of the droplets was controlled by varying the relative flow rates of MO and Ch-CNC suspension. The shape of the Ch-CNC component of the droplets was changed from a truncated sphere to a hemisphere to a crescent moon. For these three Ch-CNC phase shapes, the Ch packing of the CNC pseudolayers was preserved, however the Ch pitch reduced, which was ascribed to the change in CNC orientation at the Ch-CNC/MO interface from perpendicular to parallel. The shape of the compound droplets was tuned from a dumbbell to a sphere by reducing interfacial tension between the Ch-CNC suspension and MO phases. Photopolymerization of the monomer mixture introduced in the Ch-CNC phase of the droplets and the removal of the sacrificial MO phase enabled the generation of Ch microgels. The results of this work can be used for exploring new applications of Janus colloids and the fabrication of programmable active soft matter.