Toward industrial scale synthesis of ultrapure singlet nanoparticles with controllable sizes in a continuous gas-phase process

Abstract

Continuous gas-phase synthesis of nanoparticles is associated with rapid agglomeration, which can be a limiting factor for numerous applications. In this report, we challenge this paradigm by providing experimental evidence to support that gas-phase methods can be used to produce ultrapure non-agglomerated “singlet” nanoparticles having tunable sizes at room temperature. By controlling the temperature in the particle growth zone to guarantee complete coalescence of colliding entities, the size of singlets in principle can be regulated from that of single atoms to any desired value. We assess our results in the context of a simple analytical model to explore the dependence of singlet size on the operating conditions. Agreement of the model with experimental measurements shows that these methods can be effectively used for producing singlets that can be processed further by many alternative approaches. Combined with the capabilities of up-scaling and unlimited mixing that spark ablation enables, this study provides an easy-to-use concept for producing the key building blocks for low-cost industrial-scale nanofabrication of advanced materials.

Scalable and Environmentally Benign Process for Smart Textile Nanofinishing

“…The size of the particles produced by spark ablation can be easily controlled by varying Q q . 27 When Q q increases from 20 to 50 slm, d p decreases from ca. 3.6 to ca.…”

“…27 Predictions by equation (1) are validated with inductively coupled plasma mass spectrometry (ICP-MS) (cf. Table S3).…”

“…38 Coalescence ceases when the NPs reach a critical size beyond which agglomerates becomes dominant. 27 Comparing the peaks of the WAXS curves corresponding to the raw fabric with those of the nanofinished fabric, an additional peak at 2θ = 38.1º is related to crystalline phase Ag (111). The acquired signals are relatively weak due to the low NP loading on the fabric (cf.…”

“…Figure 2) confirm that the NPs remain non-agglomerated singlets when suspended in the gas. 27 The deposition of such singlets should decrease particle release in conjunction with strong particle adhesion to the fibers when compared to larger particles or agglomerates. Both enhanced adhesion and a large exposed surface can thus be achieved by making the particles small.…”

“…Here, we propose a sustainable and universal approach to textile nanofinishing that relies on a single-step NP synthesis and deposition process. Among the various aerosol processes, electrical discharges allow the high-yield synthesis of a wide range of well-defined NPs [20][21][22][23][24][25] (with respect to NP concentration, size, 26,27 crystallinity, 28 and chemical composition 29,30 ) that can be directly deposited onto textile fibers by diffusion, in a green and universal manner. The uniqueness of the proposed process lies in that diffusional deposition can be easily integrated into textile nanofinishing while providing a controlled loading profile within the textiles.…”