Electric-field-induced deformation, yielding, and crumpling of jammed particle shells formed on non-spherical Pickering droplets

Abstract

We studied the behavior of a nonspherical Pickering droplet subjected to an electric stress. We explained the effect of droplet geometry, particle size, and electric field strength, on the deformation and collapsing of particle-covered droplets.

Electrically modulated relaxation dynamics of pre-stretched droplets post switched-off uniaxial extensional flow

“…In the past couple of decades, there has been a growing interest in investigating droplet dynamics under electrical field, broadly under the scope of droplet electrohydrodynamics (EHD), via extensive theoretical, experimental, and numerical investigations. [32][33][34][35][36][37][38][39][40][41] In electrically mediated flows, droplet breakup is a well-known phenomenon, [42][43][44][45][46][47][48] preceding large deformation at high electrical capillary number, Ca E , signifying a decisive dominance of the electric stress over capillary stress. Fundamentally, in electric field, the droplet deforms to a new shape that is typically characterized by a discriminating function f T (R, S, l), originally introduced by Taylor, 49 where R, S and l are the ratios of electrical conductivity, permittivity and viscosity, respectively, of the droplet and the continuous phase.…”

Armored Droplets as Soft Nanocarriers for Encapsulation and Release under Flow Conditions

“…The numerical simulations discussed above allowed us to explore the design and dynamical stability of a distinctive class of soft nanocarriers inspired by Pickering nanoemulsions, which can have potential in targeted-oriented active molecule encapsulation and release under specific flow conditions. The success in controlling the creation of crater-like depressions on the surface of Pickering micron-sized droplets recently reported by Rozynek et al 26 demonstrates the plausibility of our predictions as well as the dynamics here presented. The interplay between the evolution of the structural morphology of the armored nanodroplets and the organization of the NP interfacial network, when the volume of the system is reduced, is in qualitative agreement with experimental observation.…”

“…The morphological and physicochemical properties of soft nanomaterials provide advantages that enable the design of autonomous nanoscale devices that can more closely mimic or interact with biological structures with stimulus-responsive characteristics. In this context, emulsions stabilized with nanoparticles (NPs), also know as Pickering emulsions, offer real advantages in a wide range of fundamental − or industrial and medical applications. − They can serve as a template for autonomous platforms that are able to change their shape and adopt different functionalities as a result of morphological transformation obtained via interfacial self-assembly and cross-linking, , dynamical control of the NP distribution with electric or magnetic fields, − or dynamical control of the fluidic environment, , among other techniques.…”

Emulsion-Based Delivery Systems to Enhance the Functionality of Bioactive Compounds: Towards the Use of Ingredients from Natural, Sustainable Sources

“…These emulsion-based systems present high stability and high biocompatibility without the addition of surfactants. Even under high stress, the shells covering the emulsion droplets have been found to remain in the systems [ 77 , 78 , 79 ]. Moreover, they present an adjustable permeability, meaning that the release of the encapsulated bioactive compounds can be controlled under the action of external factors such as ultrasonic waves [ 80 ].…”