Insights into the Microstructural Evolution Occurring during Pyrolysis of Metal-Modified Ceramers Studied through Selective SiO<sub>2</sub> Removal
Silicon oxycarbide ceramers containing 5% aluminum, zirconium, and cobalt with respect to the total Si amount are prepared from a commercial polysiloxane and molecular precursors and pyrolyzed at temperatures ranging from 500 to 1000 °C. HF etching is carried out to partially digest the silica phase...
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MDPI AG
2021-06-01
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| Online Access: | https://www.mdpi.com/1996-1944/14/12/3276 |
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| author | Aitana Tamayo Juan Rubio Fausto Rubio Mᵃ Angeles Rodriguez |
| author_facet | Aitana Tamayo Juan Rubio Fausto Rubio Mᵃ Angeles Rodriguez |
| author_sort | Aitana Tamayo |
| collection | DOAJ |
| description | Silicon oxycarbide ceramers containing 5% aluminum, zirconium, and cobalt with respect to the total Si amount are prepared from a commercial polysiloxane and molecular precursors and pyrolyzed at temperatures ranging from 500 to 1000 °C. HF etching is carried out to partially digest the silica phase, thus revealing structural characteristics of the materials, which depend upon the incorporated heteroatom. From the structural and textural characterization, it was deduced that when Al enters into the ceramer structure, the crosslinking degree is increased, leading to lower carbon domain size and carbon incorporation as well. On the contrary, the substitution by Zr induced a phase-separated SiO<sub>2</sub>-ZrO<sub>2</sub> network with some degree of mesoporosity even at high pyrolysis temperatures. Co, however, forms small carbidic crystallites, which strongly modifies the carbonaceous phase in such a way that even when it is added in a small amount and in combination with other heteroatoms, this transient metal dominates the structural characteristics of the ceramer material. This systematic study of the ceramer compounds allows the identification of the ultimate properties of the polymer-derived ceramic composites. |
| first_indexed | 2024-03-10T10:26:13Z |
| format | Article |
| id | doaj.art-48a390de2816474e8a37c45154bd376c |
| institution | Directory Open Access Journal |
| issn | 1996-1944 |
| language | English |
| last_indexed | 2024-03-10T10:26:13Z |
| publishDate | 2021-06-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Materials |
| spelling | doaj.art-48a390de2816474e8a37c45154bd376c2023-11-22T00:00:23ZengMDPI AGMaterials1996-19442021-06-011412327610.3390/ma14123276Insights into the Microstructural Evolution Occurring during Pyrolysis of Metal-Modified Ceramers Studied through Selective SiO<sub>2</sub> RemovalAitana Tamayo0Juan Rubio1Fausto Rubio2Mᵃ Angeles Rodriguez3Institute of Ceramics and Glass, CSIC, Kelsen 5, 28049 Madrid, SpainInstitute of Ceramics and Glass, CSIC, Kelsen 5, 28049 Madrid, SpainInstitute of Ceramics and Glass, CSIC, Kelsen 5, 28049 Madrid, SpainFaculty of Science, Department of Environmental, University of Extremadura, Avda. Elvas s/n, 06071 Badajoz, SpainSilicon oxycarbide ceramers containing 5% aluminum, zirconium, and cobalt with respect to the total Si amount are prepared from a commercial polysiloxane and molecular precursors and pyrolyzed at temperatures ranging from 500 to 1000 °C. HF etching is carried out to partially digest the silica phase, thus revealing structural characteristics of the materials, which depend upon the incorporated heteroatom. From the structural and textural characterization, it was deduced that when Al enters into the ceramer structure, the crosslinking degree is increased, leading to lower carbon domain size and carbon incorporation as well. On the contrary, the substitution by Zr induced a phase-separated SiO<sub>2</sub>-ZrO<sub>2</sub> network with some degree of mesoporosity even at high pyrolysis temperatures. Co, however, forms small carbidic crystallites, which strongly modifies the carbonaceous phase in such a way that even when it is added in a small amount and in combination with other heteroatoms, this transient metal dominates the structural characteristics of the ceramer material. This systematic study of the ceramer compounds allows the identification of the ultimate properties of the polymer-derived ceramic composites.https://www.mdpi.com/1996-1944/14/12/3276polymer-derived ceramicsceramermolecular precursorsHF etchingpyrolysisspectroscopy |
| spellingShingle | Aitana Tamayo Juan Rubio Fausto Rubio Mᵃ Angeles Rodriguez Insights into the Microstructural Evolution Occurring during Pyrolysis of Metal-Modified Ceramers Studied through Selective SiO<sub>2</sub> Removal Materials polymer-derived ceramics ceramer molecular precursors HF etching pyrolysis spectroscopy |
| title | Insights into the Microstructural Evolution Occurring during Pyrolysis of Metal-Modified Ceramers Studied through Selective SiO<sub>2</sub> Removal |
| title_full | Insights into the Microstructural Evolution Occurring during Pyrolysis of Metal-Modified Ceramers Studied through Selective SiO<sub>2</sub> Removal |
| title_fullStr | Insights into the Microstructural Evolution Occurring during Pyrolysis of Metal-Modified Ceramers Studied through Selective SiO<sub>2</sub> Removal |
| title_full_unstemmed | Insights into the Microstructural Evolution Occurring during Pyrolysis of Metal-Modified Ceramers Studied through Selective SiO<sub>2</sub> Removal |
| title_short | Insights into the Microstructural Evolution Occurring during Pyrolysis of Metal-Modified Ceramers Studied through Selective SiO<sub>2</sub> Removal |
| title_sort | insights into the microstructural evolution occurring during pyrolysis of metal modified ceramers studied through selective sio sub 2 sub removal |
| topic | polymer-derived ceramics ceramer molecular precursors HF etching pyrolysis spectroscopy |
| url | https://www.mdpi.com/1996-1944/14/12/3276 |
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