Fabrication of continuous ZrB2 nanofibers derived from boron-containing polymeric precursors

Continuous ceramic nanofibers of ZrB2 were synthesized via electrospinning combining with polymeric precursor method. The electrospinning solution was prepared from the reaction of Polyzirconoxane (PZO) with 2-Hydroxybenzyl alcohol and boric acid followed by the addition of polyvinylpyrrolidone (PVP). The influences of the solution properties and B/Zr molar ratio on electrospinning were investigated. The electrospun precursors and heat-treated nanofibers were characterized by XRD, SEM, EDS, TEM and Raman. The results showed that pyrolysis at 350 °C helped to stabilize the fibers morphology and ZrB2 nanofibers were obtained by pyrolyzing the precursor fibers at 1400 °C for 2 h in argon. ZrB2 nanofibers maintained the excellent fibrous morphology in all the samples. ZrB2 nanofibers are composed of uniformly nanosized ZrB2 particles. The average crystallite size of ZrB2 particles using Scherrer equation is 25 nm. The atomic percentages of zirconium and boron in the product formed in argon at 1400 °C were 17.06% and 33.73% respectively, which is very close to the stoichiometric ZrB2.