Synthesis of aluminium nanoparticles by arc plasma spray under atmospheric pressure

• Published in: Materials science & engineering. B, Solid-state materials for advanced technology Solid-state materials for advanced technology, 2013-01, Vol.178 (1), p.22-30
• Main Authors: Mandilas, Charalampos, Daskalos, Emmanouil, Karagiannakis, George, Konstandopoulos, Athanasios G.
• Format: Article
• Language: English
• Subjects: Aluminium; Arc discharges; Nanoparticles synthesis; Plasma
• ISSN: 0921-5107; 1873-4944
• DOI: 10.1016/j.mseb.2012.10.004

► A customized arc-plasma spraying based system has been designed and implemented. ► The system is relatively simple, robust and operates at atmospheric pressure. ► Preparation of aluminium nanoparticles from micron-sized powder was successful. ► Various nano-sized distributions were possible depending on operating parameters. ► Optimization of the proposed design will lead to higher efficiencies and throughput. The present study addresses the feasibility to synthesize aluminium nanoparticles (NPs) from micron-sized aluminium powder with the use of a customized atmospheric plasma spraying (APS) technique. Using APS, nanoparticle synthesis can be achieved via rapid melting and vaporization of the initial micrometric particles and their subsequent re-nucleation. A custom mantle system was designed and developed with the aid of relevant simplified CFD simulations. The mantle provided the necessary inert environment (argon), at ambient pressure, in order to avoid any oxidation of the metal during plasma spraying while promoted rapid quenching of the gasified metal. The particles formed were collected with the aid of a quartz filter downstream of the plasma flame and the production rate achieved was 2gmin−1. Ex situ post-characterization of the particles via X-ray diffraction, specific surface area measurement (BET), transmission electron microscopy (TEM) coupled with energy dispersive spectrometry (EDS) and thermogravimetric analysis (TGA) under air revealed that the powders obtained primarily comprised of monocrystalline metallic aluminium nanoparticles of almost spherical shape. The NPs possessed a 2–5nm oxide coating layer. By regulating the conditions inside the mantle, a variety of different size distributions were obtained.