2D Particles at Fluid–Fluid Interfaces: Assembly and Templating of Hybrid Structures for Advanced Applications

Abstract

Fluid-fluid interfaces have widespread applications in personal care products, the food industry, oil recovery, mineral processes, etc. and are also important and versatile platforms for generating advanced materials. In Pickering emulsions, particles stabilize the fluid-fluid interface, and their presence reduces the interfacial energy between the two fluids. To date, most Pickering emulsions stabilized by 2D particles make use of clay platelets or GO nanosheets. These systems have been used to template higher order hybrid, functional materials, most commonly, armored polymer particles, capsules, and Janus nanosheets. This review discusses the experimental and computational study of the assembly of sheet-like 2D particles at fluid-fluid interfaces, with an emphasis on the impact of chemical composition, and the use of these assemblies to prepare composite structures of dissimilar materials. The review culminates in a perspective on the future of Pickering emulsions using 2D particle surfactants, including new chemical modification and types of particles as well as the realization of properties and applications not possible with currently accessible systems, such as lubricants, porous structures, delivery, coatings, etc.

Multifunctional phase change microcapsules based on graphene oxide Pickering emulsion for photothermal energy conversion and superhydrophobicity

“…Even though the above method, to some extent, can alleviate the problem of microPCMs, the superfluous organic surfactants pollute the environment and restrain the applications. The effective and economical strategy is to bring in Pickering stabilizer, which can even substitute classical organic surfactants . Various types of particles, such as SiO 2, CNTs, nanocellulose, and so on, can be served as Pickering stabilizer.…”

“…The effective and economical strategy is to bring in Pickering stabilizer, which can even substitute classical organic surfactants. 18,19 Various types of particles, such as SiO 2, 20 CNTs, 21 nanocellulose, 22,23 and so on, can be served as Pickering stabilizer. According to several innovative reports, [24][25][26][27] graphene oxide (GO), an excellent two-dimensional material with amphipathy, can be worked as a Pickering stabilizer.…”

Sculpting Liquids with Two-Dimensional Materials: The Assembly of Ti3C2Tx MXene Sheets at Liquid–Liquid Interfaces

“…22,23 Their versatile properties, two-dimensional nature, inherent surface functionalization/ negative charge, and solution processability make MXenes ideal candidates for interfacial assembly and incorporation into structured liquids. The interface between immiscible liquids presents a versatile landscape for the assembly of functional nanomaterials, 24 which can be used to prepare films 25 and emulsions. 26,27 Nanoparticle (or for MXenes, nanosheet) surfactant assemblies have become an ubiquitous process for the preparation of nanomaterials and have been demonstrated with graphene oxide (GO), 28 carbon nanotubes (CNTs), 29 and metallic/semiconducting nanoparticles, among other materials.…”

Gas Barrier Polymer Nanocomposite Films Prepared by Graphene Oxide Encapsulated Polystyrene Microparticles

“…The introduction of NaCl prior to preparation of the monomer suspension results in charge screening of the oxygen containing hydroxyl and carboxylic acid groups in GO. 23,31 As the concentration of NaCl increases the negative zeta potential of the system tends towards zero, reducing the intersheet electrostatic repulsion and inducing flocculation and stacking of the GO sheets. 23,[32][33] In our experiment, the probe sonication used to disperse the GO sheets reduced their diameter slightly, as shown in Figure S6, however they are still present as multilayer stacks approximately 10 µm in diameter.…”