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Crystal structure,morphology and luminescent properties of rare earth ion-doped SrHPO4 nanomaterials
Undoped and rare earth ions(Eu3+, Ce3+, Tb3+) doped β-Sr HPO4 nanomaterials were successfully prepared by a facile hydrothermal method. The crystal structure, morphology and luminescent properties were characterized by X-ray powder diffraction(XRD), scanning electron microscopy(SEM), transmission electron microscopy(TEM), photoluminescence(PL) spectra and luminescence decay curves. The results indicated that the undoped and rare earth ions doped Sr HPO4 nanomaterials(the doping concentration was not above 7%) were well crystallized, with the same crystal structure(β-Sr HPO4). Nevertheless, the doping of rare earth ions could lead to the changing of morphology from nanoflakes to nanocrystals. Under the excitation of UV light, rare earth ions(Eu3+, Ce3+, Tb3+) doped β-Sr HPO4 nanocrystals exhibited the characteristic emission of Eu3+, Ce3+ and Tb3+ ions, respectively. The luminescence decay curves of β-Sr HPO4:Eu3+ and β-Sr HPO4:Ce3+,Tb3+ nanocrystals conformed to the double exponential fluorescence decay, and the average lifetimes were 1.14 and 4.12 ms, respectively. The luminescence decay curve of β-Sr HPO4:Ce3+ was fitted into a single exponential function, and the lifetime was about 0.78 ns. 相似文献
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对硫酸亚铁铵制备实验进行了绿色化改进,并对改进前后实验方法进行了对比分析。结果表明,实验改进后有效利用了实验室废弃物硫酸铜粉末,避免了有毒气体对环境的污染;同时,简化了实验步骤,缩短了实验时间,提高了产品的产率和质量等级,符合绿色化学的原则。 相似文献
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以对乙酰氨基酚为模型药物分子,温敏水凝胶聚N-异丙基丙烯酰胺(PNIPAAm)为载体,研究了药物在凝胶上的负载和在不同温度(25和37℃)下磷酸盐缓冲溶液(pH 7.4)中的释放行为.结果表明,对乙酰氨基酚的负载量约为35wt%,并且与载体PNIPAAm存在氢键作用.药物在磷酸盐缓冲溶液中的体外模拟释放结果显示,当温度(37℃)高于凝胶的LCST时,对乙酰氨基酚释放的较慢;当温度(25℃)低于其LCST时,释放的较快.因此,可通过环境温度的改变达到APAP在载体PNIPAAm上控制释放的目的. 相似文献
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