Please use this identifier to cite or link to this item:
|Type:||Artigo de periódico|
|Title:||Influence of multiwall carbon nanotubes on the structural and morphological features of Si-C-O ceramics derived from a hybrid polymeric precursor|
|Abstract:||This study describes the effect of multiwall carbon nanotubes MWCNT as an additional C-source on the structural and morphological features of silicon oxycarbide ceramics obtained by different heat treatment times of a hybrid polymeric precursor at 1500 degrees C under an Ar atmosphere The precursor was prepared by a hydrosilylation reaction from poly(methylsiloxane) and divinylbenzene The presence of MWCNT promoted a more effective crystallization of the SIC and c-SiO(2) phases in the resulting ceramics in comparison with those without MWCNT The heat treatment time at 1500 degrees C also affects the crystallization of the ceramic product In addition an Increase of the defect density in the Csp(2) sheets of the C(free) dispersed phase together with higher disordering of this phase were observed in the ceramics obtained from MWCNT-containing precursor The presence of MWCNT resulted in a ceramic matrix with a different morphology in relation to that observed in the absence of MWCNT with lower resistance to oxidation Moreover the extra C-source present in the ceramic matrix introduced as MWCNT reduced the solubility of SiO(2) in this matrix promoting the early segregation of SiO(4)-rich sites Consequently a more effective crystallization of SiO(2) with relatively large c-SiO(2) crystals and of beta-SiC occurred in the material with the increase of the heat treatment time (C) 2010 Elsevier B V All rights reserved|
|Editor:||Elsevier Science Sa|
|Appears in Collections:||Unicamp - Artigos e Outros Documentos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.