Synthesis of titanium nitride fibers from electrospun titania/polymer composite nanofibers

Abstract

Titanium nitride (TiN) is a non-oxide ceramic with high thermal, mechanical and chemical stabilities. Titanium nitride fibers were synthesized by carbothermal reduction and nitridation of titania/polymer composite nanofibers that were obtained from sol-gel process combined with electrospinning technique. The titania/polymer composite nanofibetrs were pyrolyzed in argon atmosphere at 600 degree Celsius to break long hydrocarbon chains into free carbon. The obtained products were still in the form of fibers and exhibited significant shrinkage as well as a reduction in fiber diameter. After that, these pyrolyzed fibers were converted to titanium nitride by the carbothermal reduction and nitridation process at 1400 degree Celsius. TiC was occurred during heating up to the reaction temperature. Titanium nitride was formed when gas supplying to the reactor was changed to nitrogen. The diameter of the obtained titanium nitride fibers was in nanometer scale when hight molecular-weight polyvinylpyrolydone was used as carbon source. In addition, the use of carbon black as carbon source was also investigated in this study. As the result, the conversion of titainium nitride obtained, when carbon black was used, was higher than that from polyvinylpyrolydone. Moreover, doubled flow rate of nitrogen did not affect the reaction, such that the conversion was not different from regular flow rate.