Authors: A. Sonnenfeld, P. Reichen, Ph.R. von Rohr
Affilation: ETH Zürich, Switzerland
Pages: 263 - 266
Keywords: nanoparticles, low temperature, normal pressure, plasma synthesis, powder processing, surface treatment, flowability, wettability
The precipitation of solid-state sphere-like nanostructures from an organosilicon precursor at atmospheric pressure is investigated in the prospect of the improvement of powder flowability by the attachment of nanoscopic spacers to the powder particles surfaces. Tetrametylsilane (TMS) is admixed to the afterglow of a low power (< 0.5 W) barrier discharge (BD). The BD occurs in a single miniature flow-channel, where Ar or He enriched with O2 are excited favoring homogeneous gas phase reactions of atomic oxygen and TMS in the afterglow. The chemical and morphological influence of Ar or He on the formation of nanostructures is explored at two positions in the afterglow by FTIR spectroscopy and SEM. For the Ar based BD, larger spherical nanostructures (100–1000 nm) of higher oxide content are evidenced, while for He polymeric deposits with characteristic sizes below 100 nm are found. In addition, the processing capability of a BD device consisting of a set of 64 miniature flow-channels is probed by means of the wettability improvement of polymer powder particles having been conveyed through the BD afterglow zone of the multi-channel device. The treatment is shown to decreases the benzyl alcohol contact angle (BACA) significantly with increasing oxygen feed.