Hydrothermal & Microwave Synthesis Of Morphology Controlled Nanoscale Functional Ceramic Powders

Compared with metal and plastic, ceramic materials have many advantages such as heat resistant and anti-rusty, which have been extensively applied to advanced technological fields. With the development of nanotechnology, nanoceramics come into being, which improve the strength and toughness of the materials. Studying on the nanoceramics becomes one of the most important tasks in the development of advanced ceramic. Ceramic powder is a necessary ingredient for the ceramics. The performance characteristics of a ceramic component are greatly influenced by precursor powder characteristics. The most crucial factor for the development of advanced ceramic is to prepare the satisfying ceramic powders. Many methods are applied for preparing the ceramic powders, such as solid state reaction, precipitation, sol-gel and hydrothermal method and so on. The hydrothermally prepared powders offer many advantages, such as high degree of crystallinity, well-controlled morphology, high purity and narrow particle size distribution. This method has been widely used in preparation of various powders in recent years. Compared with conventional method, microwave synthesis has the advantages of very short time, small particle size, narrow particle size distribution, and high purity, which make it become an active domain of scientific researches. The present thesis is aimed at exploring novel low-temperature hydrothermal & microwave irradiation methods to synthesize nanoscale functional ceramic powders, and studying the formation and morphology controlled mechanism of the ceramic powders under the hydrothermal & microwave conditions. The main researches achieved are summed up as following: 1. We succeeded in the synthesis of well crystallined phase-pure HAP nanoparticles by a simple hydrothermal method at 100~140oC. The effects of the pH value and the reaction temperature on the formed phase and morphology of HAP during the hydrothermal process were also investigated. The results indicated that they are all influencing factors on the phase and morphology of the final products. Lower pH value is favorable for the formation of needle like HAP. On controlling the above factors, well crystallined and uniform HAP nanowiskers were obtained. 2. We adopted microwave irradiation method to synthesize pure phase HAP powders in 10min. During the microwave treatment process, the effects of the pH value and complex reagent on the properties of the obtained product such as...