Dong Xiangting

Fabrication of Eu(III) complex doped nanofibrous membranes and their oxygen-sensing properties

In this paper, we report the synthesis, characterization, and photophysical properties of Eu(TTA)₃ECIP, where TTA=2-thenoyltrifluoroacetonate, and ECIP=1-ethyl-2-(N-ethyl-carbazole-yl-4-)imidazo[4,5-f]1,10-phenanthroline. Its elementary application for oxygen-sensing application is also investigated by doping it into a polymer matrix of polystyrene (PS). Experimental data suggest that the 2.5 wt% doped Eu(TTA)₃ECIP/PS nanofibrous membrane exhibits a high sensitivity of 3.4 towards oxygen with a good linear relationship of R² = 0.9962. In addition, the 2.5 wt% doped Eu(TTA)₃ECIP/PS nanofibrous membrane owns a quick response of 8s towards oxygen, along with its excellent atmosphere insensitivity and photobleaching resistance. All these results suggest that both Eu(TTA)₃ECIP and Eu(TTA)₃CIP/PS system are promising candidates for oxygen-sensing optical sensors.

Fabrication and Characterization of Gd2O3:Eu3+Luminescent Nanofibres via Electrospinning

采用静电纺丝技术制备了PVA/[Gd(NO3)3+Eu(NO3)3]复合纳米纤维,并将其进行热处理,得到Gd 2 O 3 :Eu 3+ 发光纳米纤维。X射线衍射分析表明,复合纤维为无定型,Gd 2 O 3 :Eu 3+ 发光纳米纤维属于体心立方晶系,空间群为Ia3。扫描电子显微镜(SEM)分析表明,复合纳米纤维的平均直径约为200 nm,经过800 ℃焙烧后,获得了直径约50 nm的Gd 2 O 3 :Eu 3+ 发光纳米纤维。差热热重分析表明,温度高于600 ℃时,复合纳米纤维中水份、有机物和硝酸盐分解挥发完毕,样品不再失重,总失重率为71.9%。傅里叶转换红外光谱(FTIR)分析表明,复合纳米纤维的红外光谱与纯聚乙烯醇的红外光谱基本一致,600 ℃以上生成了Gd 2 O 3 :Eu 3+ 发光纳米纤维。荧光光谱分析表明,在251 nm紫外光激发下,Gd 2 O 3 :Eu 3+ 发光纳米纤维发射出Eu 3+ 离子特征的609 nm明亮红光。讨论了Gd 2 O 3 :Eu 3+ 发光纳米纤维的形成机理,该技术可以推广用于制备其他稀土氧化物发光纳米纤维。

Preparation of nanocrystalline ZrO2 by reverse precipitation method

Nanocrystalline ZrO2 particulates with different sizes were prepared by precipitation method using ethanol as dispersive and protective reagent. XRD patterns show that the synthesized ZrO2 is monoclinic in structure with space group P21/a when calcination temperature is in the range of 400–1000°C. It is found that the smaller the particle, the bigger the crystal lattice distortion, the worse the crystal growth, and the lower the diffraction intensity. TEM images reveal that ZrO2 particles are spherical in shape, and the particle size distribution is in, narrow range. The mean sizes of the particles increase with the increase of calcination temperatures. It is first to observe the streaks of different crystallographic planes. Thermogravimetric analysis indicates that the crystallization temperature of ZrO2 is 461.32°C. Measurement of ZrO2 relative density shows that the relative density of nanocrystalline ZrO2 powders increases with the increasing of ZrO2 particle sizes.