Wyniki wyszukiwania - BazTech

1

Intercalated nanohybride structures of non-organic/organic polymer of GaSe and GaSe configuration

Grygorchak I., Ivashchyshyn F., Shvets R., Pokladok N., Stotsko Z.

Przetwórstwo Tworzyw

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2012

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[R.] 18, nr 3

200-204

EN

The introduction of polyaniline into a semiconductor GaSe matrix leads to decrease in specific resistance of GaSe system almost in 10 times, as compared to the initial expensed GaSe matrix. Under the exposure of such structure to light, a deformation of the spectrum ρ(ω) with simultaneous increase in specific resistance and in inductive response of the system takes place; increase in dielectric permittivity is also observed at a dielectric losses angle value less than unity, this is of prospect from the point of view of the application of such system in the manufacturing technology for high-quality radio-frequency capacitors and time-delay lines. The co-intercallation of the given structure with iodine leads to decrease of ρ(ω) in two times and to increase of photoconductance in two times. In GaSe structure, thermogalvanic and abnormal photovoltaic effects are detected.

2

Preparation and characterization of highly electrically and thermally conductive polymeric nanocomposites

Tavman I., Krupa I., Cecen V., Omastova M., Novak I., Ozdemir I., Turgut A.

Archives of Materials Science

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2008

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Vol. 29, nr 1-2

77-83

EN

The conducting polymers and polymeric composites have attracted considerable attention in recent years because of their potential applications in advanced technologies, for example, in antistatic coatings, electromagnetic shielding. The introduction of electrically conductive fillers such as graphite, carbon black, metal and metal oxide powders into the polymeric matrix is a promising approach to fabricate electrically conductive polymeric materials. The recent advancement of nano-scale compounding technique enables the preparation of highly electrically conductive polymeric nanocomposites with very low loading of conductive fillers. Compared with traditional composites, nanocomposites may offer enhanced physical features such as increased stiffness, strength, barrier properties and heat resistance, without loss of impact strength in a very broad range of common synthetic or natural polymers. In this study the conductive fillers were expanded graphite (EG) and untreated graphite (UG), the base material was ethylene- vinyl acetate copolymer (EVA). Nanocomposites containing up to 30 volume % of filler material were prepared by mixing them in a Brabender Plasticorder. The increase in thermal conductivity was more pronounced for EVA-UG nanocomposites than EVA-EG nanocomposites.

3

Fabrication of Al2O3/Ni-P nanocomposites with phase percolation by high pressure sintering of chemically coated alumina powders.

Michalski J., Wejrzanowski T., Konopka K., Bieliński J., Gierlotka S., Kurzydłowski K.J.

Archives of Materials Science

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2005

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Vol. 26, nr 1-2

53-58

EN

The present paper shows the possibility of fabrication, under high pressure, of composites with percolated structure from alumina powder coated with nanoparticles of Ni-P to electroless nickel plating process. This process leads to either uniformly dispersed nanoparticles of Ni-P (size range of 10-100 nm) or thin nanometric layers covering the entire grain surface of the ceramic powder. By high pressure sintering one can obtain two types of nanocomposites from coated powders: (a) Al2O3/Ni-P particulate system and (b) ceramic metal percolated structure. Three kinds of composites with percolated structures were fabricated at different temperatures and investigated by SEM and TEM. The results were compared with model structures for percolated structures.

4

Tworzywa nanokompozytowe sialon/Al2O3 otrzymywane metodą samorozwijającej się syntezy wysokotemperaturowej (SHS)

Kata D., Lis J., Morgiel J.

Archiwum Nauki o Materiałach

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1998

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t. 19, nr 3

167-177

PL

Przedstawiono wyniki badań nad preparatyką nowego materiału nanokompozytowego sialon/Al2O3. W celu wytworzenia tego nanokompozytu posłużono się techniką samorozwijającej się syntezy wysokotemperaturowej (SHS). Jest to jedna z nowych metod preparatyki tworzyw ceramicznych, dająca możliwość uzyskiwania materiałów o nowych i nie spotykanych właściwościach. Dzięki tej metodzie uzyskano nanokompozyt sialon/Al2O3 charakteryzujący się unikalną mikrostrukturą. Faza Al2O3 tworzy nanometryczne wtrącenia wewnątrz ziaren osnowy. Zastosowane przez autorów techniki badawcze, takie jak: analiza rentgenowska, transmisyjna mikroskopia elektronowa, EDS, pozwoliły na wyjaśnienie zjawiska tworzenia się nanocząstek glinu w ziarnach sialonu. Na podstawie rezultatów pracy można stwierdzić, że dzięki swoim zaletom technika SHS jest odpowiednią metodą preparatyki proszków ceramicznych do uzyskiwania materiałów nanokompozytowych.

EN

The authors present results on preparation of a new nanocomposite material in the Sialon/Al2O3 system. In order to prepare such nanocomposites the self propagating high temperature synthesis has been used. The self propagating high temperature synthesis (SHS) is a method providing special opportunities in the production of ceramic material having new very attractive properties. The Sialon/Al2O3 nanocomposite obtained by SHS is a material which is characterised by a unique microstructure. The Al2O3 phase creates nanometric inclusions in matrix grains. Transmission electron microscopy, XRD analysis and EDS technique have been used to determine this microstructure. Final results of the work have shown that the SHS method is appropriate for production of ceramic nanocomposites.