General Approach to the Evolution of Singlet Nanoparticles from a Rapidly Quenched Point Source

Abstract

Among the numerous point vapor sources, microsecond-pulsed spark ablation at atmospheric pressure is a versatile and environmentally friendly method for producing ultrapure inorganic nanoparticles ranging from singlets having sizes smaller than 1 nm to larger agglomerated structures. Due to its fast quenching and extremely high supersaturation, coagulational growth already begins at the atomic scale at room temperature. On the basis of this knowledge, we develop a simple semiempirical yet versatile model for predicting the size distribution of singlet particles as a function of the process conditions. The model assumes that a plume of a turbulent aerosol flow flares out from a concentrated point source, eventually reaching the walls of the confinement where a fraction of the particles is deposited. Despite the complexity of the entire process, the concentration and size evolution of particles can be adequately described by a first-order differential equation accounting for coagulation, turbulent dilution, and diffusional deposition to the walls. The model provides a simple and practical tool that can generally be used to design and control point vapor source reactors for the synthesis of singlets with tunable sizes starting from that of single atoms.

Scalable and Environmentally Benign Process for Smart Textile Nanofinishing

“…1.5 nm, which is corroborated by model predictions. 31 Interestingly, an increase in Q q does not diminish the deposition efficiency of the NPs significantly (cf. Section S2 in the Supporting Information).…”

Green manufacturing of metallic nanoparticles: a facile and universal approach to scaling up

“…7,19,[24][25][26][27] In addition, the method offers good control over particle size which can range from that of atomic clusters to that of singlets or agglomerates consisting of sub-10 nm primary particles. 25,28,29 This technique have focused on fabricating NPs using spark ablation (at low frequencies) for a number of new applications (Table S1). 3,6,7,19,25,29,[33][34][35][36][37][38]31,[39][40][41][42][43][44] Note that carrier gases and electrodes determine the particle composition.…”

“…25,28,29 This technique have focused on fabricating NPs using spark ablation (at low frequencies) for a number of new applications (Table S1). 3,6,7,19,25,29,[33][34][35][36][37][38]31,[39][40][41][42][43][44] Note that carrier gases and electrodes determine the particle composition. 25 Although manufacturing electrodes may not be particularly green, the use of recycled metals allows the green manufacturing of NPs.…”

“…To make the process also sustainable with respect to its energy consumption, one could couple it with a source of renewable energy (e.g., solar panels). Apart from the importance of having sub-10 nm primary particles, 29 achieving a high yield in NP synthesis is a vital prerequisite for numerous applications. The mass production rate of spark ablation is proportional to the spark repetition frequency and to the mass ablated per spark, which is related linearly to the spark energy as have been recently demonstrated both experimentally and theoretically.…”

“…The mass production rate of spark ablation is proportional to the spark repetition frequency and to the mass ablated per spark, which is related linearly to the spark energy as have been recently demonstrated both experimentally and theoretically. 29 Spark discharges using resistance-inductance-capacitance (RLC) circuits (referred to as RLCS from this point onwards; cf. Figure S1) 7,31 have an upper operating frequency threshold of a few hundred Hz.…”