Active nematic emulsions

Guillamat, Pau (author), Kos, Žiga (author), Hardoüin, Jérôme (author), Ignés-Mullol, Jordi (author), Ravnik, Miha (author), Sagués, Francesc (author)

The formation of emulsions from multiple immiscible fluids is governed by classical concepts such as surface tension, differential chemical affinity and viscosity, and the action of surface-active agents. Much less is known about emulsification when one of the components is active and thus inherently not constrained by the laws of thermodynamic equilibrium. We demonstrate one such realization consisting in the encapsulation of an active liquid crystal (LC)–like gel, based on microtubules and kinesin molecular motors, into a thermotropic LC. These active nematic emulsions exhibit a variety of dynamic behaviors that arise from the cross-talk between topological defects separately residing in the active and passive components. Using numerical simulations, we show a feedback mechanism by which active flows continuously drive the passive defects that, in response, resolve the otherwise degenerated trajectories of the active defects. Our experiments show that the choice of surfactant, which stabilizes the active/passive interface, allows tuning the regularity of the self-sustained dynamic events. The hybrid active-passive system demonstrated here provides new perspectives for dynamic self-assembly driven by an active material but regulated by the equilibrium properties of the passive component.

• Language: English
• Keywords: liquid crystals, nematic emulsions
• Work type: Article
• Typology: 1.01 - Original Scientific Article
• Organization: FMF - Faculty of Mathematics and Physics
• Publication status: Published
• Publication version: Version of Record
• Year: 2018
• Number of pages: 10 str.
• Numbering: Vol. 4, no. 4, art. eaao1470
• PID: 20.500.12556/RUL-128501
• UDC: 538.9
• ISSN on article: 2375-2548
• DOI: 10.1126/sciadv.aao1470
• COBISS.SI-ID: 3197796
• Publication date in RUL: 15.07.2021

Record is a part of a journal

• Title: Science advances
• Publisher: American Association for the Advancement of Science
• ISSN: 2375-2548
• COBISS.SI-ID: 523392025

Licences

• License: CC BY-NC 4.0, Creative Commons Attribution-NonCommercial 4.0 International
• Link: http://creativecommons.org/licenses/by-nc/4.0/
• Description: A creative commons license that bans commercial use, but the users don’t have to license their derivative works on the same terms.
• Licensing start date: 06.04.2018

Secondary language

• Language: Slovenian
• Keywords: tekoči kristali, nematske emulzije