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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Influence of multiwall carbon nanotubes on the structural and morphological features of Si-C-O ceramics derived from a hybrid polymeric precursor

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Author(s):
Segatelli, Mariana Gava [1, 2] ; Radovanovic, Eduardo [3] ; Nunes Pires, Alfredo Tiburcio [4] ; Goncalves, Maria do Carmo [1] ; Pagotto Yoshida, Inez Valeria [1]
Total Authors: 5
Affiliation:
[1] Univ Estadual Campinas, Inst Chem, BR-13083970 Campinas, SP - Brazil
[2] Univ Estadual Londrina, Dept Chem, BR-86051990 Londrina, PR - Brazil
[3] Univ Estadual Maringa, Dept Chem, BR-87020900 Maringa, PR - Brazil
[4] Univ Fed Santa Catarina, Dept Chem, BR-88040970 Florianopolis, SC - Brazil
Total Affiliations: 4
Document type: Journal article
Source: Materials Chemistry and Physics; v. 124, n. 2-3, p. 1216-1224, DEC 1 2010.
Web of Science Citations: 7
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 (AU)

FAPESP's process: 03/09926-1 - Polymeric and ceramic materials
Grantee:Inez Valeria Pagotto Yoshida
Support Opportunities: PRONEX Research - Thematic Grants