Interfacially-adsorbed particles enhance the self-propulsion of oil droplets in aqueous surfactant

Understanding the chemo-mechanical mechanisms that direct the motion of self-propulsive colloids is important for the development of active materials and exploration of dynamic, collective phenomena. Here, we demonstrate that the adsorption of solid particles on the surface of solubilizing oil droplets can significantly enhance the droplets’ self-propulsion speeds. We investigate the relationship between the self-propulsion of bromodecane oil droplets containing silica particles of varying concentration in Triton X-100 surfactant, noting up to order of magnitude increases in propulsion speeds. Using fluorescently labeled silica, we observe packing of the particles at the oil-water interfaces of the rear pole of the moving droplets. For bromodecane oil droplets in Triton X-100, the highest droplet speeds were achieved at approximately 40% particle surface coverage of the droplet interface. We find particle-assisted propulsion enhancement in ionic surfactants and different oil droplet compositions as well, demonstrating the breadth of this effect. While a precise mechanism for the propulsion enhancement remains unclear, the simple addition of silica particles to droplet oil-water interfaces provides a straightforward route to tune active droplet dynamics.



Work Title Interfacially-adsorbed particles enhance the self-propulsion of oil droplets in aqueous surfactant
Open Access
  1. Seong Ik Cheon
  2. Leonardo Batista Capaverde Silva
  3. Aditya S. Khair
  4. Lauren D. Zarzar
License In Copyright (Rights Reserved)
Work Type Article
  1. Soft Matter
Publication Date July 28, 2021
Publisher Identifier (DOI)
Deposited November 15, 2021




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Work History

Version 1

  • Created
  • Added manuscript.pdf
  • Added Creator Seong Ik Cheon
  • Added Creator Leonardo Batista Capaverde Silva
  • Added Creator Aditya S. Khair
  • Added Creator Lauren D. Zarzar
  • Published
  • Updated
  • Updated