Creation of Gases with Interplanetary Oxygen Concentration at Atmospheric Pressure by Nanoparticle Aerosol Scavengers: Implications for Metal Processing from nm to mm Range

Abstract

A gas purification setup (GPS) is presented that is capable of producing ultrapure inert gases, such as nitrogen, at ambient pressure with residual oxygen concentrations of 10–13 ppm and below. The GPS relies on the interaction of metallic aerosol nanoparticles that capture residual oxygen, resulting in metal oxide particle formation. The finally reached residual oxygen level can be illustrated by the 6.8 billion years needed for the creation of one monolayer of oxygen on a substrate. Consequently, the processing of oxygen-affine materials of any size may be shifted from vacuum processes toward machining steps at atmospheric pressure, maintaining an oxygen-free environment in the future. As an outlook, the presented work includes measurements of the electron work function of nanoparticles under purified (10–13 ppm-level) and unpurified process gas (100 ppm-level), pointing at the strong influence of residual oxygen on nanostructured materials with reference to copper nanoparticles. Future syntheses and applications of nanoscaled structures will be inspired by the opportunity to work with true inert gases at ambient pressure, which has been inaccessible so far.