scholarly journals Janus Particles at Fluid Interfaces: Stability and Interfacial Rheology

Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 374
Author(s):  
Elton L. Correia ◽  
Nick Brown ◽  
Sepideh Razavi
Keyword(s):  
Colloidal Particles ◽  
Janus Particles ◽  
Shear Stresses ◽  
Fluid Interfaces ◽  
Interfacial Rheology ◽  
Pickering Emulsions ◽  
Interfacial Mechanics ◽  
Anisotropic Surface ◽  
Particle Anisotropy

The use of the Janus motif in colloidal particles, i.e., anisotropic surface properties on opposite faces, has gained significant attention in the bottom-up assembly of novel functional structures, design of active nanomotors, biological sensing and imaging, and polymer blend compatibilization. This review is focused on the behavior of Janus particles in interfacial systems, such as particle-stabilized (i.e., Pickering) emulsions and foams, where stabilization is achieved through the binding of particles to fluid interfaces. In many such applications, the interface could be subjected to deformations, producing compression and shear stresses. Besides the physicochemical properties of the particle, their behavior under flow will also impact the performance of the resulting system. This review article provides a synopsis of interfacial stability and rheology in particle-laden interfaces to highlight the role of the Janus motif, and how particle anisotropy affects interfacial mechanics.

Behavior of Janus Particles at Liquid Interfaces

2014 ◽  
Author(s):  
Hossein Rezvantalab ◽  
Shahab Shojaei-Zadeh
Keyword(s):  
Small Difference ◽  
Separation Distance ◽  
Janus Particles ◽  
Interface Plane ◽  
Fluid Interfaces ◽  
Liquid Interfaces ◽  
Ellipsoidal Particles ◽  
Particle Force ◽  
Energetic Interactions

We study the capillary-induced interactions and configuration of spherical and non-spherical Janus particles adsorbed at flat liquid-fluid interfaces. For Janus spheres, the equilibrium orientation results in each hemisphere being exposed to its more favored fluid. However, experimental observations suggest that some of these particles may take a tilted orientation at the interface, giving rise to a deformed interface. On the other hand, Janus ellipsoids with a large aspect ratio or a small difference in the wettability of the two regions tend to tilt even at equilibrium. The overlap of deformed menisci results in energetic interactions between neighboring particles. We numerically calculate the interface shape around the particles by minimizing the total surface energy of the system comprising of the interface and particle-fluid regions. We quantify these interactions through evaluation of capillary energy variation as a function of the orientation and separation distance between the particles. We find that Janus spheres with similar orientations undergo a relative realignment in the interface plane in order to minimize the capillary energy. In case of ellipsoidal particles, the particles assemble in a preferred side-by-side configuration. We evaluate the role of anisotropy and degree of amphiphilicity on the inter-particle force and the capillary torque. The results can be used to predict the migration and oriented assembly of Janus particles with various geometrical and surface properties at liquid-fluid interfaces.

scholarly journals Substrate wettability guided oriented self assembly of Janus particles

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Meneka Banik ◽  
Shaili Sett ◽  
Chirodeep Bakli ◽  
Arup Kumar Raychaudhuri ◽  
Suman Chakraborty ◽  
...  
Keyword(s):  
Self Assembly ◽  
Janus Particles ◽  
Water Molecules ◽  
Functional Coatings ◽  
Hexagonal Close Packed ◽  
Local Densities ◽  
Inhomogeneous Properties ◽  
Metal Polymer ◽  
Specific Orientation

AbstractSelf-assembly of Janus particles with spatial inhomogeneous properties is of fundamental importance in diverse areas of sciences and has been extensively observed as a favorably functionalized fluidic interface or in a dilute solution. Interestingly, the unique and non-trivial role of surface wettability on oriented self-assembly of Janus particles has remained largely unexplored. Here, the exclusive role of substrate wettability in directing the orientation of amphiphilic metal-polymer Bifacial spherical Janus particles, obtained by topo-selective metal deposition on colloidal Polymestyere (PS) particles, is explored by drop casting a dilute dispersion of the Janus colloids. While all particles orient with their polymeric (hydrophobic) and metallic (hydrophilic) sides facing upwards on hydrophilic and hydrophobic substrates respectively, they exhibit random orientation on a neutral substrate. The substrate wettability guided orientation of the Janus particles is captured using molecular dynamic simulation, which highlights that the arrangement of water molecules and their local densities near the substrate guide the specific orientation. Finally, it is shown that by spin coating it becomes possible to create a hexagonal close-packed array of the Janus colloids with specific orientation on differential wettability substrates. The results reported here open up new possibilities of substrate-wettability driven functional coatings of Janus particles, which has hitherto remained unexplored.

scholarly journals Active colloidal particles at fluid-fluid interfaces

2017 ◽  
Vol 32 ◽  
pp. 57-68 ◽  
Author(s):  
Wenjie Fei ◽  
Yang Gu ◽  
Kyle J.M. Bishop
Keyword(s):  
Colloidal Particles ◽  
Fluid Interfaces

scholarly journals Pickering emulsions stabilized by colloidal surfactants: Role of solid particles

Particuology ◽  
2021 ◽  
Author(s):  
Zhu Sun ◽  
Xiaoxiao Yan ◽  
Yao Xiao ◽  
Lingjie Hu ◽  
Max Eggersdorfer ◽  
...  
Keyword(s):  
Solid Particles ◽  
Pickering Emulsions

Surface activity of Janus particles adsorbed at fluid–fluid interfaces: Theoretical and experimental aspects

2016 ◽  
Vol 233 ◽  
pp. 240-254 ◽  
Author(s):  
Miguel Angel Fernandez-Rodriguez ◽  
Miguel Angel Rodriguez-Valverde ◽  
Miguel Angel Cabrerizo-Vilchez ◽  
Roque Hidalgo-Alvarez
Keyword(s):  
Surface Activity ◽  
Janus Particles ◽  
Fluid Interfaces

scholarly journals Multivalent weak interactions enhance selectivity of interparticle binding

2020 ◽  
Vol 117 (37) ◽  
pp. 22690-22697 ◽  
Author(s):  
M. R. W. Scheepers ◽  
L. J. van IJzendoorn ◽  
M. W. J. Prins
Keyword(s):  
Targeted Drug Delivery ◽  
Colloidal Particles ◽  
High Selectivity ◽  
Weak Interactions ◽  
Theoretical Work ◽  
Coated Particles ◽  
Receptor Interactions ◽  
Two Factors ◽  
Experimental Findings

Targeted drug delivery critically depends on the binding selectivity of cargo-transporting colloidal particles. Extensive theoretical work has shown that two factors are necessary to achieve high selectivity for a threshold receptor density: multivalency and weak interactions. Here, we study a model system of DNA-coated particles with multivalent and weak interactions that mimics ligand–receptor interactions between particles and cells. Using an optomagnetic cluster experiment, particle aggregation rates are measured as a function of ligand and receptor densities. The measured aggregation rates show that the binding becomes more selective for shorter DNA ligand–receptor pairs, proving that multivalent weak interactions lead to enhanced selectivity in interparticle binding. Simulations confirm the experimental findings and show the role of ligand–receptor dissociation in the selectivity of the weak multivalent binding.

Engineering functional alginate beads for encapsulation of Pickering emulsions stabilized by colloidal particles

RSC Advances ◽  
2016 ◽  
Vol 6 (103) ◽  
pp. 101267-101276 ◽  
Author(s):  
Hongshan Liang ◽  
Bin Zhou ◽  
Jing Li ◽  
Yun He ◽  
Yaqiong Pei ◽  
...  
Keyword(s):  
Sustained Release ◽  
Colloidal Particles ◽  
Alginate Beads ◽  
Delivery Systems ◽  
Pickering Emulsions ◽  
Pharmaceutical Industries ◽  
Hydrophilic Compounds

Pickering emulsions are widely used as delivery systems in food, cosmetics, and pharmaceutical industries for the encapsulation and sustained release of hydrophilic compounds.

Capillary interactions between spherical Janus particles at liquid–fluid interfaces

Soft Matter ◽  
2013 ◽  
Vol 9 (13) ◽  
pp. 3640 ◽  
Author(s):  
Hossein Rezvantalab ◽  
Shahab Shojaei-Zadeh
Keyword(s):  
Janus Particles ◽  
Fluid Interfaces ◽  
Capillary Interactions
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