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Nanocomposite varnishes
Hlavčo, Tomáš ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work deals with issues of nanoparts and nanotechnology and it’s applications in the sphere of dielectrics. Primary objective has been to make series of varnish samples filled with nanoparts. Then we have measured dependencies of absorber and resorber currents and we have been monitoring changes of dielectric properties against unfulfilled samples. Used materials were epoxy resin TSA 220S filled with nanoparts of silicon oxide.
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Nanocomposite varnishes
Hlavčo, Tomáš ; Rozsívalová, Zdenka (referee) ; Frk, Martin (advisor)
This work deals with issues of nanoparts and nanotechnology and it’s applications in the sphere of dielectrics. Primary objective has been to make series of varnish samples filled with nanoparts. Then we have measured dependencies of absorber and resorber currents and we have been monitoring changes of dielectric properties against unfulfilled samples. Used materials were epoxy resin TSA 220S filled with nanoparts of silicon oxide.
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Analytical electron microscopy of lead-free nanopowder solders
Buršík, Jiří ; Sopoušek, J. ; Zálešák, Jakub ; Buršíková, V.
During the last decade, the EU legislative regulations enforced lead-free solders and hence initiated an extensive search for the best replacement of lead-containing solders. Parallel to new binary and ternary bulk solders, metal nanoparticles are also considered as potential candidates for solder materials. It is known that physical, electric and thermodynamic properties of nanoobjects are significantly different from those of the bulk materials. The oxidation, high reactivity of the surfaces and aggregation are frequent problems of nanotechnology applications. The nanoparticles of pure metals and alloys exhibit the depression of the melting point compared to bulk material, hence they are able to aggregate and to form firm interlayer joints at low temperatures. Exploiting this effect can save energy, work and materials.
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Electron microscopy of nanoparticles for lead-free soldering prepared by wet chemical synthesis
Buršík, Jiří ; Škoda, D. ; Vykoukal, V. ; Sopoušek, J.
The nanoparticles of pure metals and alloys exhibit the depression of the melting point compared to bulk material, hence they are able to aggregate and to from firm interlayer joints at low temperatures. Exploiting this effect in soldering industry can save energy, work and materials. Using emulsions with nanopowders might be the solution of demanding task of replacing classical Sn-Pb solders by their lead-free substitutes. In this work, Ag- and Sn-based nanopowders were prepared as potential low-toxic constituents of novel solders by a chemical wet synthesis from chemicals of high purity. Various ways of preparation and further storage of the product were examined. Resulting nanoparticles (their size distribution, morphology and tendency for clustering) were characterization by means of scanning and transmission electron microscopy.
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