Effect of dispersants on the physicochemical properties of ultra-fine ZrB2 powder in Sol-gel synthesis

Boride-based ultra-high temperature ceramics have been extensively utilized as high temperature thermal protection materials due to its excellent physical and mechanical properties . Yet, the synthesis of boride-based ceramic powder with high purity, ultra-fine structure and excellent dispersity remains a great challenge to reach. In this work, zirconium diboride (ZrB 2 ) ultra-high temperature ceramic powder with high purity and ultra-fine structure (size of hundreds of nanometers) was prepared by carbothermal reaction combined with sol-gel method. Various dispersants including oleic acid (OA), polyethylene glycol (PEG) and polyvinyl pyrrolidone (PVP) were employed during the preparation procedure to tune the physicochemical properties of the resultant ZrB 2 . According to the X-ray diffraction and microscopy characterizations, it was revealed that the OA turned up as the most effective dispersant to obtain the ZrB 2 powder with hundreds-nanometer-scale and high purity. Besides, the thermogravimetry-differential thermal analysis and Fourier transformed infrared spectroscopy analysis were performed, unveiling the function of OA in enhancing the dispersity of the ZrB 2 . Such a work on the effect of dispersant on the preparation of ultra-high temperature ceramic powder could shed some important light for the development of high temperature resistant materials.