Structure and properties of white Si–O–C(–H) ceramics derived from polycarbosilane by thermal oxidation curing and H₂ decarbonization process

Abstract

SiOC(H) ceramics were synthesized from polycarbosilane (PCS) by a combinatorial procedure of thermal oxidation curing and H 2 decarbonization. In the case of PCS precursor with particle form (diameters of 100500 nm), thermal oxidation curing at 340°C was most effective to achieve white appearance with photoluminescence even after H 2 decarbonization at 800 or 1100°C. In the case of fiber form (diameter of 10¯m), the curing temperature of 290°C was effective to obtain white PL fiber after the decarbonization at 800°C. Heat treatment at 1100°C, however, changed the color of the fiber to black. Spectroscopic analysis of the decarbonized products revealed that structure of the white materials with strong PL mainly consisted of SiO 4 SiO 3 C mixed units, whereas incorporation of SiC 4 units decreased PL intensity. In addition, the materials with apparent PL usually exhibited a sharp absorption band at 880 cm ¹1 in FT-IR spectra, which was possibly assigned to a kind of SiC bonds modified by hydrogen incorporated in the amorphous network.

Microphase Separation 3D Printing of Binary Inorganic Polymer Precursors to Prepare Nanostructured Carbon‐Ceramic Multimaterials

“…These are assigned to Si 1s→ 𝜎* transitions, where 𝜎* corresponds to the valence antibonding Si-X (Si-C or Si─O) orbitals, respectively (Table S9, Supporting Information). [30,48,49] The broadness of the main peak suggests the co-existence of two distinct chemical states of Si within the materials, originating from both C and O atoms. This observation aligns with our prior work on PIMS 3D-printed SMP-10-derived ceramic materials, where similar SiOC phases were identified.…”