One-pot synthesis of fluorescent hybrid nanoparticles and their assembly into transparent and multi-coloured nanofilms

Abstract

We developed a route for one-pot synthesis of fluorescent hybrid nanoparticles and their assembly into a nanofilm by utilizing a fusion and fission-triggered nanoreactor system based on water-in-oil "miniemulsion". A fluorescent nanocrystal, ZnS:Mn 2+ , was produced in a confined system via fusion and fission of nanodroplets induced by ultrasonication and the amount of nanocrystals formed in each nanoreactor was easily controlled. Then, in situ polymerisation allowed for encapsulation of nanocrystals inside polymer nanoparticles, leading to an efficient surface capping of nanocrystals with polymers and hence a strong light emission under UV irradiation. Also, hybrid nanoparticles with different colours could be created by tuning of Mn 2+ doping into ZnS nanocrystals, which can give rise to an energy transfer from carboxylic groups of surface capping polymers to the Mn 2+ . These hybrid nanoparticles were then spin-coated to form hybrid nanofilms where nanocrystals were uniformly distributed. The multicolour tuning of nanofilms was achieved simply by mixing nanoparticles with ZnS-derived blue emission and those with ZnS:Mn 2+ -derived orange emission. We believe that our nanoreactor system would offer a viable way in creating fluorescent nanomaterials.

An Effective Two‐Emulsion Approach to the Synthesis of Doped ZnS Crystalline Nanostructures

“…Furthermore, unlike microemulsions, miniemulsion droplets retain their identity throughout the reaction and are therefore well suited to confine the crystallization process within their core 10. Fukui et al recently developed a miniemulsion‐based route to produce hybrid ZnS–polyhydroxyethyl methacrylate films 11. Their approach led to the possibility of obtaining multicolored films by varying the ratio of pure ZnS and ZnS:Mn II NPs encapsulated in thin films, which show blue and orange luminescence, respectively.…”

One‐pot preparation of multicolor polymeric nanoparticles with high brightness by single wavelength excitation

“…Nowadays, other fascinating routes involve multicolor fluorescent nanoparticles (MFNs) assembled from materials like polymer, gold, silica and other inorganic materials have also been investigated . Most of these nanoparticles were designed with the encapsulation of three or more tandem organic/inorganic fluorophores, to construct a cascade fluorescence resonance energy transfer (FRET) system upon excitation .…”