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Influence of Size Effects on Homogeneous Nucleation Inside Nanoparticles
Levdansky, V.V. ; Smolík, Jiří ; Ždímal, Vladimír ; Moravec, Pavel
It is known that many physicochemical processes in aerosol systems with nanoscale particles and in nanoparticles themselves depend on the particle size. The influence of size dependence of the condensation coefficient on gas-phase nucleation was discussed in (Levdansky et al., 2010). Some problems related to nucleation in confined space, in particular the depletion effect of the ambient phase, were considered in (Kožíšek et al., 2011; Schmelzer and Abyzov, 2011). Here we study the size effects in homogeneous nucleation inside nanoparticles related to size dependence of the effective rate constant for the attachment of monomers to the critical cluster.
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Aerosol Nanoparticles Formed during Plasma Deposition
Ždímal, Vladimír ; Moravec, Pavel ; Doležal, B. ; Brožek, Vlastimil ; Neufuss, Karel
Results of pilot-plant experiments on a plasmatron WSPR constructed at the Institute of IPP AS CR are shown in this paper, dealing with plasma deposition of the ultrafine and fine aerosol fractions of some metallic materials. In this work we concentrated on its side-product investigating the ultrafine particles released during the process into the aerosol phase. The aerosol particle size distribution was studied in a near real time using the state-of-the-art aerosol spectrometers operated by the ICPF AS CR. It was verified that these instruments are able to take aerosol samples in the close vicinity of a high-temperature plasma and still provide sensible results. In the present work we discussed the possibility to produce aerosol nanoparticles of a defined composition and properties by the plasmatron technique.
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Application of Nanofibres in Filtration Processes
Kimmer, D. ; Vincent, I. ; Petras, D. ; Fenyk, J. ; Zatloukal, M. ; Sambaer, W. ; Slobodian, P. ; Salmela, H. ; Lehtimaki, M. ; Ždímal, Vladimír
The metod making possible to achieve the requireed of the nanofibres is demonstrated on the influence of telative humidity and solvent type on the fibre- forming process taking place in an electrostatic field. the effect of homogenity of the nanofibre deposition on the collection substrate is assessed empoying images from scanning electron microscopy (SEM) and tests of filtering abilities oh the nanofibre layers. Also, some measurements obtained when nanofibres were used in filtation of air, liquids and dispersions of carbon nanotubes in a liquid are presented.
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