Lignin-Silica-Titania Hybrids as Precursors for Si–Ti–C–O Fibers

Lignin-silica-titania and lignin-titania hybrid fibers have been prepared by sol-gel processing from lignin, tetraethoxysilane, and titanium tetrakis(2,4-pentanedionate) using a mixture of 2,4-pentanedione and tetrahydrofuran as solvent and H2SO4 as catalyst. Amounts of H2O and H2SO4, to add to the solutions with the Si-to-Ti atomic ratios of 0–1.0, were determined for achieving favorable spinnability of fibers from the solutions. The FT-IR spectrum of the fibers indicated the formation of hybrid fibers. The hybrid fibers, cured in air to avoid coalescense, could be converted into Si–Ti–C and TiC fibers upon pyrolysis at 1500°C in Ar.