Hybrid nanostructured particles via surfactant-free double miniemulsion polymerization

Abstract

Double emulsions are complex fluid systems, in which droplets of a dispersed liquid phase contain even smaller dispersed liquid droplets. Particularly, water-in-oil-in-water double emulsions provide significant advantages over simple oil-in-water emulsions for microencapsulation, such as carrier of both aqueous and oily payloads and sustained release profile. However, double emulsions are thermodynamically unstable systems consisting typically of relatively large droplets. Here we show that nanoscale water-in-oil-in-water double emulsions can be prepared by adding a silica precursor polymer, hyperbranched polyethoxysiloxane, to the oil phase without any additional surfactants. The resulting double miniemulsions are transformed to robust water@SiO2@polymer@SiO2 nanocapsules via conversion of the precursor to silica and polymerization of the oil phase. Other intriguing nanostructures like nanorattles and Janus-like nanomushrooms can also be obtained by changing preparation conditions. This simple surfactant-free double miniemulsion polymerization technique opens a promising avenue for mass production of various complex hybrid nanostructures that are amenable to numerous applications.

Fundamentals and Design‐Led Synthesis of Emulsion‐Templated Porous Materials for Environmental Applications

“…However, the typical double emulsions are thermodynamically unstable systems owing to their relatively large droplet size. [35,36,[52][53][54] Usually, the preparation of the double emulsions involves a two-step emulsification process, wherein a primary emulsion is formed under high shear conditions followed by the subsequent dispersion of the primary emulsion into another incompatible phase under a relatively mild shear force in order to avoid rupture of the internal water droplets. [35,36,52] An example of how a W/O/W emulsion can be prepared is illustrated in Figure 2d.…”

“…However, the typical double emulsions are thermodynamically unstable systems owing to their relatively large droplet size. [ 35 , 36 , 52 , 53 , 54 ]…”

“…Double emulsions are generally polydisperse and poorly controlled in structure because each emulsification step leads to a wider distribution of droplets in size. However, monodisperse double emulsions with better control of droplet size may be produced by membrane emulsification, [ 54 , 55 ] microcapillary device, [ 54 , 55 , 56 ] or microfluidics in general. [ 57 ]…”

Out‐of‐the‐Box Nanocapsules Packed with On‐Demand Hydrophobic Anticancer Drugs for Lung Targeting, Esterase Triggering, and Synergy Therapy

“…Polymer nanocapsules as one of popular DDSs [ 24–28 ] present enormous advantages: enhancing the solubility of hydrophobic drugs which can improve their bioavailability; low polymer content as compared to other nanoparticle drug delivery systems, which leads to the reduction of the stimulations of tissue; and controlled release of drugs in tumor microenvironment. [ 29–31 ] So far, many reaction residues are toxic and the reactions are complex with low drug entrapment efficiency, which greatly restrict the applications of nanocapsules in drug delivery. [ 32,33 ] Remarkably, those polymer nanocapsules generally need a careful design of conjugation, complexation, or co‐self‐assembly for drug loading, which limits the on‐demand hydrophobic anticancer drug delivery as well as loading other concomitant drugs for synergy therapy.…”

Miniemulsion of nano encapsulated dye for highly efficient polyester dying

“…It is an aqueous diffusion of comparatively settled oily droplets preparation by a system of oil/water with surfactant blind with low waterinsoluble compound by ultra-sonication or homogenization, so-called hydrophobic whose functionality responsible for restricting decaying of droplet [13]. The specifications of the mini emulsion polymerization are encapsulated of nanoparticles which can be taken out via instantly to dispersing the hydrophobic particles and nucleating all the droplets in miniemulsions [14].…”