Janus Cylinders at Liquid–Liquid Interfaces

Abstract

We describe the first study on the self-assembly behavior of Janus cylinders at liquid/liquid interfaces. The Janus cylinders are characterized by a phase separation along the major axis into two hemicylinders of different wettability. The pendant drop technique and microscopic imaging were used to characterize the adsorption behavior and self-assembly of Janus cylinders at perfluorinated oil/dioxane and perfluorinated oil/dimethyl sulfoxide interfaces. According to the evolution of the interfacial tension and a series of TEM images taken during the cylinder adsorption, we will specify the characteristics of early to late stages of the Janus cylinder adsorption at a liquid-liquid interface and discuss the effect of Janus cylinder length and their concentration. We also establish that the broken symmetry of the corona leads to significantly higher interfacial activity as compared to homogeneous core-shell cylinders. The adsorption is characterized by three different adsorption stages: first, free diffusion to the interface, followed by continuous adsorption of cylinders including ordering and domain formation and, finally, additional packing with a rearrangement of domains and formation of a loose multilayer system.

The equilibrium shape of fluid-fluid interfaces: Derivation and a new numerical method for Young’s and Young-Laplace equations

“…II, we have presented a short proof that the Young-Laplace Eq. (18) and Young's Law (24) derive from the minimization of the thermodynamic potential (Eq. (1)) of the fluid-fluid system.…”

“…(24). Thus, given the fluid volumes and the configuration of the external solid surfaces, the input parameters that determine the shape of the fluid-fluid interface are cos θ and ℓ.…”

“…The capillary interactions induced by these deformations can be exploited, for example, in the selfassembly of interface adsorbed colloidal particles, [13][14][15][16] which can be directed by manipulating, e.g., the interface shape, [17][18][19] the particle shape, [20][21][22][23] or the particle concentration. 24,25 The capillary deformations may also play an important role in the adsorption of a single non-spherical colloidal particle at a fluid-fluid interface, which is a recurrent issue in soft matter (e.g., Refs. [26][27][28][29][30].…”

Fabrication of Janus particles composed of poly (lactic-co-glycolic) acid and hard fat using a solvent evaporation method

“…Janus particles have been reported to show unique properties that conventional homogeneous particles do not possess, and have been proposed for use in various applications including as amphiphilic surfactants (16), elementary particles of the display in an electric field (17), and particles for magnetolytic therapy (18). Recently, the pulmonary delivery of hydrophilic and hydrophobic anticancer drugs has been reported (19).…”

Design, Synthesis, and Application of Anisotropic Janus Particles

“…Also, they studied the self-assembly of Janus cylinders at liquid/liquid interfaces. They found that the Janus cylinders can significantly enhance surface activity in comparison to homogeneous cylindrical copolymer particles although such Janus cylinders are slightly amphipathic [54]. Further, the Janus concept also can be extended to A-B-A and A-B-C structures except for the general A-B structure.…”