Carboranyl Units Bringing Unusual Thermal and Structural Properties to Hybrid Materials Prepared by Sol-Gel Process
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- 作者：Ará ; ntzazu Gonzá ; lez-Campo ; Bruno Boury ; Francesc Teixidor ; Rosario Nú ; ñ ; ez
- 刊名：Chemistry of Materials
- 出版年：2006
- 出版时间：September 5, 2006
- 年：2006
- 卷：18
- 期：18
- 页码：4344 - 4353
- 全文大小：708K
- 年卷期：v.18,no.18(September 5, 2006)
- ISSN：1520-5002
文摘
Strategies for the preparation of carboranyl-containing hybrid materials by hydrolytic sol-gel processwere investigated with carboranyl-containing poly-trialkoxysilyl precursors: 1,2-[(CH2)3Si(OEt)3]2-1,2-C2B10H10 (P1) and 1-R-2-Si[(CH2)2Si(OEt)3]3-1,2-C2B10H10 (R = Me, P2 or Ph, P3). When P1 is used,the integrity of the precursor is preserved whatever is the catalyst (F-, H+), while for P2 and P3, cleavageof the Ccluster-Si bond is observed with F- and OH- as catalysts. Such Si-Ccluster bond cleavage leads toporous hybrid materials templated by the carborane, which is further eliminated from the material andtotally recovered. In contrast, nonporous materials are obtained when carborane is preserved in thematerials. Part of this hybrid material exhibits a lamellar structure in relation to the presence of thecarborane units. In dry air, high thermal stability is observed for such materials and results in a verylimited oxidation of the material at 1200 
C (weight gain of <5%). In an inert atmosphere, high thermalstability combined with several chemical transformations leads to a limited weight loss, graphitization,and oxide and under-oxide mixtures. Materials were characterized by IR, solid-state NMR (29Si,13C),porosimetry, X-ray diffraction, SEM, TEM, TGA, and XPS.
C (weight gain of <5%). In an inert atmosphere, high thermalstability combined with several chemical transformations leads to a limited weight loss, graphitization,and oxide and under-oxide mixtures. Materials were characterized by IR, solid-state NMR (29Si,13C),porosimetry, X-ray diffraction, SEM, TEM, TGA, and XPS.