Direct Visualization of Symmetry Breaking During Janus Nanoparticle Formation

Abstract

The straight-forward synthesis of Janus nanoparticles composed of Ag and AgBr is reported. For their formation, cucurbit[n]uril (CB)-stabilized AgBr nanoparticles are first generated in water by precipitation. Subsequent irradiation with an electron beam transforms a fraction of each AgBr nanoparticle into Ag(0) , leading to well-defined Janus particles, stabilized by the binding of CB to the surface of both AgBr and Ag(0) . With the silver ion reduction being triggered by the electron beam, the progress of the transformation can be directly monitored with a transmission electron microscope.

DNA-modulated photo-transformation of AgCl to silver nanoparticles: visiting the formation mechanism

“…For instance, the nanostructures obtained at pH 3 were of a widely distributed morphology and size, and those obtained at pH 4 showed cubic structures with small spherical deposits. These differences could be attributed to the distinct features of AgX-bearing heterogeneous Ag nanostructure growth under these pH conditions [66]. Interestingly, spherical nanostructures were increasingly observed at pH 5, as well as some branched and merged spherical nanostructures.…”

Metal‐halide Nanoparticle Formation: Electrolytic and Chemical Synthesis of Mercury(I) Chloride Nanoparticles

“…[7][8][9] Other methods include the controlled precipitation of metal halides in aqueous media, for example, AgBr NP suspensions stabilised in solution by materials such as gelatine [10] and cucurbit[n]uril macrocycles. [11] Although the area has seen significant development, there are few examples for the formation of particles of sizes 20-100 nm without complex multi-step chemical processes and stabilising organic coatings. [12] The use of stabilising materials has also been shown to effect the size of the NPs depending on the sample preparation for analysis, with drying of the NPs resulting in significantly different structures to those in suspension.…”

“…[12] The use of stabilising materials has also been shown to effect the size of the NPs depending on the sample preparation for analysis, with drying of the NPs resulting in significantly different structures to those in suspension. [11] A new method for the analysis of NPs in suspension is the electrolysis of individual NPs by using the nanoimpact technique. [13,14] This involves the characterisation of NPs according to their interaction with an electrode when colliding under Brownian motion.…”

Electrochemical Nanoparticle Sizing Via Nano‐Impacts: How Large a Nanoparticle Can be Measured?

“…These techniques, however, are not always applicable. Electron microscopes are ex situ, have an inherently high cost associated with their operation, and require drying of the sample, which has been shown to promote particle agglomeration . Optical techniques such as DLS, whilst in situ, suffer from the inability to characterise polydisperse or optically opaque samples, as well as being challenged by smaller NPs.…”

“…Electron microscopes are ex situ, have an inherently high cost associated with their operation, and require drying of the sample, which has been shownt op romote particle agglomeration. [2] Optical techniques such as DLS, whilst in situ, suffer from the inability to characterise polydisperse or optically opaque samples, as well as being challenged by smaller NPs. Nanoparticle tracking analysis( NTA) is an alternative in situ light-scattering technique which tracks individual NPs and can be accurate for sizing both monodisperse andp olydisperse samples.…”