Interfacial Instability as Shaping Mechanism for Polystyrene Particles with Tunable Surface Texture

Abstract

Surfactant‐driven interfacial instability of emulsion droplets has recently emerged as a means for shaping polymeric particles with controllable surface texture. This paper presents a suspension polymerization‐based method to produce surface‐textured polystyrene particles by inducing an instability at the interface of prepolymerized emulsion droplets followed by rapid cooling. The interaction of two surface‐active components, i.e., arachidic acid and cetyltrimethylammonium bromide (CTAB) at the phase boundary triggers the interfacial deformation at a specific point in time. Rapid cooling freezes the deformed emulsion droplets in a nonequilibrium state. Viscosity is proposed as the key parameter influencing the particle morphology, which can be controlled by easily adjustable factors such as initiator concentration, temperature, time, and cooling rate. Contact angle hysteresis measurements of particle thin layers spread on a flat substrate reveal a strong influence of the particle surface texture on the wetting behavior. The presented particle synthesis method requires no specialized equipment and has a high potential for upscaling, making it promising for various applications including hydrophobic coatings, catalyst supports, separation technology, tissue engineering, or drug delivery.

Building block copolymer particles via self‐assembly within a droplet

“…The generation of interfacial instability of BCP emulsion droplets can be attributed to a reduction in interfacial tension between organic solvent and water, which is driven by the enrichment of surfactant. 73 The adsorption of interfacial active ingredients at the interface of emulsion droplets can cause the interfacial tension to vanish or transiently become negative. However, the role of the solvent can't be negligible, Zhu and Hayward 74 have investigated the influence of the component of organic solvents on the interfacial tension and instabilities of shrinking emulsion droplet containing PS-b-PEO.…”

Microfluidic Engineering of Crater–Terrain Hydrogel Microparticles: Toward Novel Cell Carriers

“…Several approaches have been developed to controllably tailor the surface texture of hydrogel microparticles, including solvent evaporation, , phase separation, and surfactant-driven interfacial instability . However, these methods have intrinsic limitations.…”

“…Several approaches have been developed to controllably tailor the surface texture of hydrogel microparticles, including solvent evaporation, 20,21 phase separation, 22 and surfactantdriven interfacial instability. 23 However, these methods have intrinsic limitations. First, they are usually material selective; that is, various methodologies need to be transformed to meet the customization requirements of different materials.…”

Supramolecular nanofibers via protrusion budding interfacial membrane

“…24 The procedure is facile, simply involving the dissolution of BCPs in cosolvents and emulsification of the polymer solution in the presence of surfactants. 25,26 The structure of the self-assemblies is greatly influenced by the type and concentration of the surfactants. 27 Recently, in our experiment to achieve robust Janus hollow spheres by crosslinking the self-assembled monolayer at the oil-water emulsion droplet stabilized with the triblock terpolymer of PS-P2VP-PEO, we serendipitously found that some filaments adhered to the oil/water emulsion membrane, which resembled the ''membrane budding'' 28 process in living organisms.…”

“…24 The procedure is facile, simply involving the dissolution of BCPs in co-solvents and emulsification of the polymer solution in the presence of surfactants. 25,26 The structure of the self-assemblies is greatly influenced by the type and concentration of the surfactants. 27…”