Controlling Colloidal Superparticle Growth Through Solvophobic Interactions

Abstract

A supramolecular chemistry approach is used to make supercrystalline spherical colloidal superparticles (SPs, see picture) from nanoparticles. Detailed mechanistic studies show that the formation of the SPs is a two‐step process. The major driving force for superparticle formation is the solvophobic interaction between nanoparticle building blocks and the growth solution; fine‐tuning the interaction led to a size‐controlled synthesis.

Quantum‐Dot‐Tagged Reduced Graphene Oxide Nanocomposites for Bright Fluorescence Bioimaging and Photothermal Therapy Monitored In Situ

“…As illustrated schematically in Figure 1 b, when TOPO is partially substituted by 11-mercaptoundecanoic acid (MUA), a monolayer organic shell of a well-defi ned thickness was formed on the QD surfaces. This became apparent by examination of the self-assembled QD aggregates, each of which formed a face-centered-cubic (fcc) array of QDs [22][23][24] with a lattice parameter of 7.4 nm and a closest QD spacing of 5.36 nm (see Figure S1); this is clearly shown in Figure 1 c by the "110-lattice fringe imaging" [ 22 ] of the fcc QD array oriented in the 001 zone axis, under transmission electron microscopy (TEM). These fi gures and their enlargement (e.g., Figure) show a well-ordered particle (3.6 nm) array separated by gaps of 1.7 nm, which may be attributed to the organic coating.…”

A Nanoparticle Size Series for In Vivo Fluorescence Imaging

“…The hydrodynamic diameter (HD) of waterdispersible single QDs can range from 5-40 nm depending on the organic capping ligands. [11,12] Larger sized nanoparticle constructs (>40 nm) have been previously achieved by aggregation [13,14], by adsorbing QDs to larger particles [15], or by growing silica shells around individual QDs. [16] However, these larger constructs tend to have limitations either in their size range, their stability in aqueous solution, or in their brightness.…”

Tunable Localized Resonances of Spherical Composite Particles at Optical and Near-Infrared Frequencies

“…However, less is known about how to fabricate nano-particles in the form of SCPs with well-controlled size and shape. Zhuang et al reported an approach which leads to synthesis of high-quality composite particles [21]. The proposed composite particles are similar in structure to the so-called colloidal superparticles that comprise metal oxide nano-particles and that experience growth controlled through solvophobic interactions.…”