Title :
Synthesis and characterization of hollow nanoparticles in RF dusty plasma
Author :
Matsoukas, T. ; Cao, Jun
Author_Institution :
Dept. of Chem. Eng., Pennsylvania State Univ., University Park, PA, USA
Abstract :
Summary form only given. Here we report the formation of hollow nanoparticles by low-pressure processing. The presence of hydrocarbons in a glow discharge leads to the formation cross-linked solids, often referred to as plasma polymers. We show that plasma polymerization can under certain conditions lead to the formation of submicron spherical particles with a hollow center. These particles are formed in the plasma, become trapped in the electrode sheath and eventually deposit on the electrodes when the plasma is extinguished. The samples are analyzed under TEM, by FTIR and by image analysis. Sixteen organic vapors, both aliphatic and aromatic, were investigated of which 14 were found to result in reproducible formation of submicron spheres with a hollow center. Particle sizes vary from 70 nm to almost a micron while the size of the core varies from 20 nm to 150 nm. We hypothesize that the formation of solid particles is preceded by the formation of a liquid-like droplet which solidifies under prolonged exposure of its surface to the plasma. This hypothesis predicts a linear relationship between core and outside diameter which is verified experimentally for all 14 precursors that produce hollow particles.
Keywords :
Fourier transform spectra; dusty plasmas; glow discharges; infrared spectra; materials preparation; nanoparticles; particle size; plasma materials processing; plasma pressure; plasma sheaths; polymerisation; transmission electron microscopy; FTIR spectroscopy; RF dusty plasma; TEM; cross-linked solids; glow discharge; guest molecules; hollow nanoparticles; hydrocarbons; image analysis; imaging applications; liquid-like droplet; low pressure processing; nanoencapsulation; organic vapors; particle sizes; photonic applications; plasma polymerization; plasma polymers; plasma sheath; plasma surface; submicron sphere formation; submicron spherical particles; surface-mass ratio; well-defined geometrical properties; Dusty plasma; Electrodes; Hydrocarbons; Image analysis; Nanoparticles; Plasma materials processing; Plasma sheaths; Polymers; Radio frequency; Solids;
Conference_Titel :
Plasma Science, 2004. ICOPS 2004. IEEE Conference Record - Abstracts. The 31st IEEE International Conference on
Conference_Location :
Baltimore, MD, USA
Print_ISBN :
0-7803-8334-6
DOI :
10.1109/PLASMA.2004.1340166