Study On Preparation And Properties Of Pb₃B₁₀O₁₆[OH]₄

With the rapid development of nuclear science and aerospace technology, humans will increasingly frequent activities in the presence of a variety of radiation, including alpha particles, beta particles,?-rays, neutron environment and serious threat the health and future generations of mankind, the need to take effective measures for prevention and control. Among them, the most difficult protection of the two types of radiation is the gamma rays and neutrons, and their characteristics are different, very representative. Simultaneously effective protection neutrons and ?-rays of other materials can also be effective in protecting the function of other rays, such as ceramics,cement or combination of lead and boron composite plates, etc..However, these materials can not meet the requirements of quality,volume, strength and toughness, such as aerospace, mobile nuclear facilities. Therefore, it is of great practical significance to prepare a kind of material that can protect the neutron and gamma rays.In this paper, Successfully prepared along the direction of [210]preferential growth and has good thermal stability Pb3B10O16[OH]4hexagonal crystal by a simple solvothermal method and phase,characterized by means of XRD, SEM and TEM. Pb3B10O16[OH]4crystals with different morphologies were prepared by adjusting the reaction conditions, different doses of H3BO3 and reaction temperature have great influence on the morphology of the product, however, the reaction time has little effect on the morphology. Preliminary explore the formation mechanism of different morphologies crystals, reactant concentration and temperature controlled crystal nucleus and the influence of crystal growth, once the formation of crystal nucleus with special morphologies formed by crystal Ostwald ripening process.Crystal photoluminescence tests by fluorescence spectrophotometer,the gamma ray shielding properties and thermal stability of the composites were analyzed by the gamma ray spectrometer and thermalanalyzer, and the shielding ability of the composite material to the thermal neutron was simulated. The results showed that the crystals with different size and morphology in 496 nm has a strong blue green photoluminescence peak, indicating that the photoluminescence properties mainly influence factors is the crystal structure, crystal defects on the surface of many flower-like structure showed the strongest photoluminescence intensity, followed by whiskers, and the strength of urchin-like crystal was the weakest. The simulated shielding rate of thermal neutron is as high as 95.23%, the gamma ray shielding rate is 39.73%, the shielding ability of different morphologies of the crystal is different, the whisker is the best, the structure of the flower is the second, the sea urchin like crystal is relatively poor. The initial thermal decomposition temperature of the composite is higher than that of the PS to 400 C, and the whisker is more favorable for improving the thermal stability of the composite. Therefore, the more regular morphology, better crystallinity, better dispersion of the whisker can help to improve the thermal neutron gamma ray shielding performance and thermal stability.