Estimation of particle size distributions obtained by gas phase processes

• Published in: Journal of nanoparticle research : an interdisciplinary forum for nanoscale science and technology Vol. 13; no. 9; pp. 3899 - 3909
• Main Author: Vollath, Dieter
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.09.2011; Springer Nature B.V
• Subjects: Characterization and Evaluation of Materials; Chemistry and Materials Science; Inorganic Chemistry; Lasers; Markov chains; Materials Science; Mathematical models; Nanocomposites; Nanomaterials; Nanoparticles; Nanostructure; Nanotechnology; Optical Devices; Optics; Particle size; Particle size distribution; Photonics; Physical Chemistry; Precursors; Research Paper; Residues; Aerosols; Particle size distribution; Conventional process; Rf-process; Microwave process
• ISSN: 1388-0764; 1572-896X
• DOI: 10.1007/s11051-011-0343-x

Nanoparticles intended for high value added applications often require special size distributions. Based on model calculations, this article compares the particle size distributions obtained with conventional and plasma processes. The model is based on an estimation of the probability for collisions; either for neutral or equally charged particles, whereas the growth of the particles is calculated using a model derived from Markov chains. The results of these calculations confirm the empirical knowledge that, under the special conditions of particles carrying electric charges of equal sign, plasma processes deliver products with the narrowest particle size distribution. Synthesis of extremely small particles with conventional processes leads to a significant residue of unreacted precursor. This finding is important in cases of expensive educts. The results of these model calculations are in perfect agreement with experimental findings.