Electrospinning of preceramic polymers for the preparation of SiBNC felts and their modification with semiconductor nanowires

Preceramic polymers obtained from the aminolysis of dichloroboryl-methyl-trichlorosilyl-amine (DMTA) were processed to ceramic felts of SiBNC by electrospinning, followed by curing in ammonia and subsequent pyrolysis. An amorphous ceramic with the composition SiBN2.4C1.4 was obtained in 60% yield, which was stable against crystallization and mass loss above 1565 °C. The pyrolysed felts showed a fiber thickness ranging between 2 and 3 μm and revealed seamless connectivity among the fibers. The rheological properties of the precursor could be tuned by adjusting the polymer/solvent ratio. Solutions with 40 wt% polymer were reproducibly spun into preceramic felts, whereas lower concentrations (10 wt%) mainly led to agglomerated powders containing few fibers. Given their intertwined morphology and high-temperature stability, the SiBNC felts were used as substrates to grow tin oxide nanowires by chemical vapour deposition for potential application as electrode materials in gas sensing, demonstrated by preliminary experiments.