Plasma-assisted gas-phase aggregation of clusters for functional nanomaterials

Abstract

The application of low-temperature plasma-based methods for the synthesis of functional nanomaterials has been growing for several decades and nanoparticles (NPs) play an increasing role in this effort. NPs have been considered for numerous applications such as optoelectronic energy conversion, electrocatalysis for fuel cells, novel plasmonic materials, electroluminescence, macromolecular self-assembly, supramolecular chemistry, and biomedical applications. The focus of this review will be devoted to NPs prepared by vacuum-based plasma-assisted sources. In the majority of cases, plasma has been excited by a planar magnetron. At first, concisely, the state-of-the-art of plasma-based gas aggregation cluster sources is presented. Then, the stability of the deposition process and enhancement of the production yield as well as tailoring of the composition, structure, and shape of NPs are discussed. In addition, in-flight modification of NPs, the interaction of NPs with a substrate, and deposition onto the liquids are presented.

Challenges in the deposition of plasma polymer nanoparticles using gas aggregation source: Rebounding upon impact and how to land them on a substrate

“…While such pp‐NPs are quite easy to produce and their formation is relatively insensitive to the purity of the process, the greatest and often overlooked challenge is to collect them on the substrate. [ 55 ] Unlike metal or metal oxide NPs, the reflection of plasma polymer or plasma polymer containing NPs from a substrate readily occurs and has been observed in all our previous experiments, [ 37,40,41,49,52–54,56,57 ] even though it was not always realized at the time. In other words, while the NPs beam may be very intense (in the right conditions, the deposition rates were shown to reach values of micrometers per second), the incoming pp‐NPs may also completely rebound when they hit the substrate, leaving no deposit.…”

Resistive Switching Effect in Ag‐poly(ethylene Glycol) Nanofluids: Novel Avenue Toward Neuromorphic Materials

“…[22,23] The precise control over the process parameters, such as magnetron current or aggregation pressure, allows easy tuning of the properties of NPs. [24] Gas-aggregated NPs may serve as individual building units for solid-state nanoobject networks. Electrical phenomena in percolating NPs networks have been studied for ≈20 years [25][26][27] ; however, the resistive switching effect was first observed 10 years ago in percolating networks of tin NPs.…”

“…[ 22,23 ] The precise control over the process parameters, such as magnetron current or aggregation pressure, allows easy tuning of the properties of NPs. [ 24 ]…”