Core–Shell Particles: From Fabrication Methods to Diverse Manipulation Techniques

Abstract

Core–shell particles are micro- or nanoparticles with solid, liquid, or gas cores encapsulated by protective solid shells. The unique composition of core and shell materials imparts smart properties on the particles. Core–shell particles are gaining increasing attention as tuneable and versatile carriers for pharmaceutical and biomedical applications including targeted drug delivery, controlled drug release, and biosensing. This review provides an overview of fabrication methods for core–shell particles followed by a brief discussion of their application and a detailed analysis of their manipulation including assembly, sorting, and triggered release. We compile current methodologies employed for manipulation of core–shell particles and demonstrate how existing methods of assembly and sorting micro/nanospheres can be adopted or modified for core–shell particles. Various triggered release approaches for diagnostics and drug delivery are also discussed in detail.

Photonic Crystal Films Based on Polymer Particles with a Core/Shell Structure Responding to Ethanol

“…Kim and coauthors considering core/shell particles with poly­(butyl acrylate)-based shell attributed the formation of such a structure of the surface layer to the contraction of the domains of the forming polymer-monomer shell parts. As the conversion of butyl acrylate increases, the swollen polymer chains contracts with the formation of “dents” in the surface layer of particles . During the synthesis of PSt@P­(MMA-BA) particles by semi-batch emulsion polymerization, the shell is enriched by butyl acrylate polymer chains, therefore, such a shell is “soft”.…”

“…As the conversion of butyl acrylate increases, the swollen polymer chains contracts with the formation of "dents" in the surface layer of particles. 31 During the synthesis of PSt@P(MMA-BA) particles by semibatch emulsion polymerization, the shell is enriched by butyl acrylate polymer chains, therefore, such a shell is "soft". As a result, the interparticle space in 3D-ordered films based on such PSt@P(MMA-BA) particles is filled with a shell polymer (Figure 2e,f, inset), since at a temperature of ∼45 °C the shell polymer passes into a viscous-flow state.…”

“…At the same time, the shape and size of the core particles should not be deformed under the influence of external factors (temperature, pressure, solvents, etc.). On the contrary, the shell should be formed based on thermoplastic polymers or elastomers. , Generally, PSt is used as a polymer for the core, while both a homopolymerpoly­(ethyl acrylate), poly­(methyl methacrylate), poly­(butylacrylate), etc., or a copolymer may form a shell. − In order to synthesize core/shell particles, both semi-batch emulsion polymerization and seed emulsion polymerization are being investigated. − Earlier we have studied the method of seed emulsion polymerization for the synthesis of polymeric particles of the core/shell structure with molecular imprints of aromatic compounds (benzene, toluene, etc.) .…”

Enhanced Optical Management in Organic Solar Cells by Virtue of Square-Lattice Triple Core-Shell Nanostructures

“…We can say that the effect of triple core-shell nanospheres above the PEDOT:PSS layer was at a higher percentage of 80%, compared to introduction of triple core-shell nanospheres in the other layers of OSC with a ZnO optical spacer layer. The different methods and techniques for fabrication of core-shell nanoparticles have been investigated in recent years [ 41 ], which helps select the appropriate method for suitable applications.…”

Synthesis and active sorting of magnetic liquid beads

“…Liquid beads differ from liquid marbles (Aussillous and Quéré 2006) based on their shell composition; liquid beads have solid shells whereas liquid marbles have a soft powdered coating as shells. The shell material of the liquid beads can be either organic polymers or inorganic substances such as metal, metal oxides, and silica or some combination of organic-inorganic materials (Chong et al 2015;Yadav et al 2023). Liquid beads have gained increasing attention due to their distinctive core and shell structure leading to promising applications.…”