نوع مقاله : تالیفی
نویسندگان
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Carbon foams based on polymeric resins and precursors, due to such properties as low
thermal conductivity, good thermal stability, high specific strength and low density,
are used in different industries, especially aerospace, as high temperature insulator, thermal
shields and material protecting structures. In this study, current methods of preparing
carbon nanostructures are introduced. By a polymeric template method polymeric foam and
aerogel are produced using the foaming process of polymer precursors of phenolic resins
and sol-gel formation. Then, the polymeric nanostructure transforms into carbon foams
in a carbonization process. Nevertheless, structural destruction due to oxidation reaction
has limited the application of these nanostructures at temperature higher than 400˚C in
the air atmosphere. In the next step, the oxidation mechanism of carbon foams is studied.
In addition to control and optimization of the process parameters such as temperature of
carbonization process, the oxidation-resistant material such as silicon carbide compounds
can be used to improve the oxidation resistance of carbon aerogel. Finally, the role of
formation of a silicon carbide layer on the surface of carbon pores wall, and the formation
of SiC bonds in the carbon aerogel structure by alkoxy silane polymers, as efficient methods
that increase the oxidation resistance of the carbon foam, is investigated.
کلیدواژهها [English]
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