Abstract
Si–O–C(–H) ceramics were synthesized from polycarbosilane (PCS) by a combinatorial procedure of thermal oxidation curing and H2 decarbonization. In the case of PCS precursor with particle form (diameters of 100–500 nm), thermal oxidation curing at 340°C was most effective to achieve white appearance with photoluminescence even after H2 decarbonization at 800 or 1100°C. In the case of fiber form (diameter of 10 µm), 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 SiO4–SiO3C mixed units, whereas incorporation of SiC4 units decreased PL intensity. In addition, the materials with apparent PL usually exhibited a sharp absorption band at 880 cm−1 in FT-IR spectra, which was possibly assigned to a kind of Si–C bonds modified by hydrogen incorporated in the amorphous network.
