Hairy Uniform Permanently Ligated Hollow Nanoparticles with Precise Dimension Control and Tunable Optical Properties

Abstract

The ability to tailor the size and shape of nanoparticles (NPs) enables the investigation into the correlation between these parameters and optical, optoelectronic, electrical, magnetic, and catalytic properties. Despite several effective approaches available to synthesize NPs with a hollow interior, it remains challenging to have a general strategy for creating a wide diversity of high-quality hollow NPs with different dimensions and compositions on demand. Herein, we report on a general and robust strategy to in situ crafting of monodisperse hairy hollow noble metal NPs by capitalizing on rationally designed amphiphilic star-like triblock copolymers as nanoreactors. The intermediate blocks of star-like triblock copolymers can associate with metal precursors via strong interaction (i.e., direct coordination or electrostatic interaction), followed by reduction to yield hollow noble metal NPs. Notably, the outer blocks of star-like triblock copolymers function as ligands that intimately and permanently passivate the surface of hollow noble metal NPs (i.e., forming hairy permanently ligated hollow NPs with superior solubility in nonpolar solvents). More importantly, the diameter of the hollow interior and the thickness of the shell of NPs can be readily controlled. As such, the dimension-dependent optical properties of hollow NPs are scrutinized by combining experimental studies and theoretical modeling. The dye encapsulation/release studies indicated that hollow NPs may be utilized as attractive guest molecule nanocarriers. As the diversity of precursors are amenable to this star-like triblock copolymer nanoreactor strategy, it can conceptually be extended to produce a rich variety of hairy hollow NPs with different dimensions and functionalities for applications in catalysis, water purification, optical devices, lightweight fillers, and energy conversion and storage.

Silver Metallic Cyclodextrin‐Core Star mPEG

“…From the viewpoint of molecular aggregation states, they may be unimolecular micelles, or multi‐molecular self‐assemblies (even ones with novel morphology) . Therefore, star polymers have found wide applications in some fields such as drug delivery, catalytic systems, and nanoreactors . With respect to construction of star polymers, β‐cyclodextrin (β‐CD) is widely used as the core, due to its 21 hydroxy groups for reactive sites.…”

“…Therefore, star polymers have found wide applications in some fields such as drug delivery, catalytic systems, and nanoreactors . With respect to construction of star polymers, β‐cyclodextrin (β‐CD) is widely used as the core, due to its 21 hydroxy groups for reactive sites. In our previous work, we synthesized β‐CD‐core star copolymer with Y‐shaped ABC miktoarms poly(ethylmethacrylate(‐ b ‐poly(2‐(diethylamino)ethyl methacrylate)‐ b ‐methoxypolyethylene glycol (PEMA(‐ b ‐PDEA)‐ b ‐mPEG) and the doxorubicin (DOX)‐conjugated β‐CD‐core star nano‐copolymer prodrugs .…”

“…It is expected that they exhibit metallic unimolecular micelles in aqueous solution. Currently, examples of metallic β‐CD‐core star polymers are limited, especially ones with direct water solubility.…”

“…So far it has been an efficient strategy for incorporation of functional groups into a macromolecular architecture to synthesize metallic polymers in situ or to have metal nanoparticles stabilized by a polymer. The functional groups should be ones, which are able to reduce metal ions into zerovalent, or to coordinate or to electrostatically interact with metal ions, guaranteeing the fact that metal ions are able to be directed onto the target position of a macromolecular architecture and then metal nanoparticles are produced in situ . For example, Black et al .…”

Asymmetric attachment and functionalization of plasmonic nanoparticles on ceramic interfaces

“…Beside conventional preparation methods, such as solvothermal reactions, a variety of specialized protocols for nanocluster formation, e.g., using nanoreactors [2] are reported in the literature. In the field of biomedicine, nanoparticles (NPs) have become more and more important.…”