The HF etching of a silicon(boron)oxycarbide glass was, for the first time, followed in situ by synchrotron radiation X-ray diffraction. The starting Si(B)OC glass is formed by two interpenetrating nano-sized networks, one SiO2-rich and the other C-rich comprising β-SiC nanocrystals and nanocrystalline graphite. The silica-based phase is dissolved by the HF forming a porous C-rich Si(B)OC. The XRD analysis shows the quantitative evolution with the etching time of all nanocrystalline phases, including the amorphous SiO2-based one. The rate-limiting step for the dissolution is the diffusion of the reactants/products through the porous C-rich Si(B)OC. The XRD analysis shows also a trend of the basal spacing of the sp2 carbon phase as a function of the dissolution time suggesting the presence, in the un-etched glass, of a in-plane residual compressive stress which is relaxed by etching out the SiO2–based network. At the end of the dissolution process the BET analysis shows the formation of a micro-meso porous C-rich Si(B)OC with a SSA of 595 m2/g, mesopore size in the range 2-10 nm and pore volume of 0.863 cm3/g.
C-rich micro/mesoporous Si(B)OC: in situ diffraction analysis of the HF etching process / Sorarù, Gian Domenico; R., Pena Alonso; Leoni, Matteo. - In: MICROPOROUS AND MESOPOROUS MATERIALS. - ISSN 1387-1811. - STAMPA. - 172(2013), pp. 125-130. [10.1016/j.micromeso.2013.01.026]
Titolo: | C-rich micro/mesoporous Si(B)OC: in situ diffraction analysis of the HF etching process | |
Autori: | Sorarù, Gian Domenico; R., Pena Alonso; Leoni, Matteo | |
Autori Unitn: | ||
Titolo del periodico: | MICROPOROUS AND MESOPOROUS MATERIALS | |
Anno di pubblicazione: | 2013 | |
Codice identificativo Scopus: | 2-s2.0-84874713591 | |
Codice identificativo WOS: | WOS:000316923900017 | |
Digital Object Identifier (DOI): | http://dx.doi.org/10.1016/j.micromeso.2013.01.026 | |
Handle: | http://hdl.handle.net/11572/96365 | |
Citazione: | C-rich micro/mesoporous Si(B)OC: in situ diffraction analysis of the HF etching process / Sorarù, Gian Domenico; R., Pena Alonso; Leoni, Matteo. - In: MICROPOROUS AND MESOPOROUS MATERIALS. - ISSN 1387-1811. - STAMPA. - 172(2013), pp. 125-130. [10.1016/j.micromeso.2013.01.026] | |
Appare nelle tipologie: | 03.1 Articolo su rivista (Journal article) |
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