Controllable Fabrication of Highly Uniform Sub-10 nm Nanoparticles from Spontaneous Confined Nanoemulsification

Sub-10 nm nanoparticles are known to exhibit extraordinary size-dependent properties for wide applications. Many approaches have been developed for synthesizing sub-10 nm inorganic nanoparticles, but the fabrication of sub-10 nm polymeric nanoparticles is still challenging. Here, a scalable, spontaneous confined nanoemulsification strategy that produces uniform sub-10 nm nanodroplets for template synthesis of sub-10 nm polymeric nanoparticles is proposed. This strategy introduces a high-concentration interfacial reaction to create overpopulated surfactants that are insoluble at the droplet surface. These overpopulated surfactants act as barriers, resulting in highly accumulated surfactants inside the droplet via a confined reaction. These surfactants exhibit significantly changed packing geometry, solubility, and interfacial activity to enhance the molecular-level impact on interfacial instability for creating sub-10 nm nanoemulsions via self-burst nanoemulsification. Using the nanodroplets as templates, the fabrication of uniform sub-10 nm polymeric nanoparticles, as small as 3.5 nm, made from biocompatible polymers and capable of efficient drug encapsulation is demonstrated. This work opens up brand-new opportunities to easily create sub-10 nm nanoemulsions and advanced ultrasmall functional nanoparticles.

Automated summary

A scalable, spontaneous confined nanoemulsification strategy is proposed for the synthesis of uniform sub-10 nm polymeric nanoparticles. By introducing a high-concentration interfacial reaction, overpopulated surfactants insoluble at the droplet surface are formed as barriers, resulting in highly accumulated surfactants inside the droplet. These surfactants exhibit significantly changed packing geometry, solubility, and interfacial activity, leading to the creation of sub-10 nm nanoemulsions via self-burst nanoemulsification. Using the nanodroplets as templates, uniform sub-10 nm polymeric nanoparticles as small as 3.5 nm, made from biocompatible polymers and capable of efficient drug encapsulation, are demonstrated. This work opens up new opportunities for the creation of sub-10 nm nanoemulsions and advanced ultrasmall functional nanoparticles.