氟化物中Eu^2＋,Ce^3＋的浓度猝灭及其机理

本文详细地研究了ＢａＹＦ５和ＫＣａＦ３基质中Ｅｕ＾２＋、Ｃｅ＾３＋浓度对其发光的影响，发现两基质中Ｅｕ＾２＋、Ｃｅ＾３＋的猝灭浓度都较低；提出了Ｅｕ＾２＋、Ｃｅ＾３＋的浓度猝灭机理，计算了猝灭浓度和临界距离，并与实验结果进行了比较。     

Gd3+,Eu3+在介孔Y2O3中的能量传递

通过模板法与溶胶-凝胶法相结合,在温和的条件下制备了介孔Y2O3.再采用水热反应法制得Eu3+、Gd3+单掺杂及Eu3+,Gd3+双掺杂的三种介孔Y2O3组装体(介孔Y2O3∶Eu3+,介孔Y2O3∶Gd3+,介孔Y2O3∶Eu3+,Gd3+).利用广角和小角X射线衍射(XRD)、透射电子显微镜(TEM)对介孔Y2O3进行了表征,结果表明,所制备的介孔Y2O3为立方相,具有六方孔道结构,孔径约10nm.对介孔Y2O3和组装体系进行了荧光光谱(PL)分析,发现在550℃热扩散处理后,介孔Y2O3∶Eu3+的发光存在基质对Eu3+的能量传递,Y2O3∶Eu3+,Gd3+体系中Gd3+对Eu3+也有能量传递作用.     

Synthesis and characterization of needle-like BaAleO4：Eu,Dy phosphor via hydrothermal-homogeneous precipitation method

A needle-like Eu2+ and Dy3+ co-doped BaAl2O4 long-lasting phosphor was synthesized via a hydrothermal-homogeneous precipitation method assisted by cetyl trimethyl ammonium bromide(CTAB) as a template.The crystal structure,morphology and optical properties of the composites were characterized.XRD results showed that the single-phase BaAl2O4 was formed at 900 ℃ in an active carbon atmosphere,which was much lower than that prepared by traditional solid-state reaction method.Scanning electron microscopy(SEM) and transmission electron microscopy(TEM) observation revealed that the precursor had well-dispersed distribution and showed needle-like morphology with the average diameter of about 100 nm and the length up to 1 μm.The final product,BaAl2O4:Eu2+,Dy3+ phosphor,inherited the needle-like shape from precursor via adding the surfactant CTAB.After irradiation by ultraviolet radiation with 355 nm for 5 min,the phosphors emitted bluish green color long-lasting phosphorescence corresponding to the typical emission of Eu2+ ion.Both the photoluminescence spectra and luminance decay revealed that the phosphor had efficient luminescent and long-lasting properties.     

Preparation and characterization of flower-like SrAl2O4:Eu2+,Dy3+ phosphors by sol-gel process

A flower-like Eu2+ and Dy3+ co-doped SrAl2O4 long-lasting phosphorescent (LLP) phosphor was synthesized via the inorganic- salt-based sol-gel method.The crystal structure,morphology and optical properties of the composite were characterized.X-ray diffraction diffu-sion (XRD) data and DSC-TG curves of the phosphor revealed that the SrAl2O4 crystallites have been formed after the precursor was calcined at 900 °C and to be single-phase SrAl2O4 at 1100 °C.The SEM photographs indicated that the sample exhibited ...     

一种简单的溶剂热法合成炭微球

利用一种简单的溶剂法合成炭微球.采用无水乙醇作为碳源和溶剂,以无水乙醇还原Ni(Ac)_2得到的Ni作为催化剂,最佳反应条件:温度500℃、时间48h.采用X-射线衍射仪(XRD)、透射电子显微镜(TEM)、扫描电子显微镜(SEM)以及Raman光谱对样品的成分、晶体结构和形貌进行了分析.结果表明:产品为圆球形和纺锤形两种形貌的炭微球,圆球形炭微球直径为1μm～2μm,纺锤形炭微球直径为1μm～2μm,长度为3μm～6μm.此法简便易行,炭微球的产率高达95%以上,且具有较规则的形貌和窄的尺寸分布.     

季铵盐改性蒙脱土的抗菌活性及抗菌机理

采用离子交换法将不同季钱盐插层到钠基蒙脱土中制备了改性蒙脱土.改性蒙脱土对革兰氏阳性菌(S.aereus)和革兰氏阴性菌(E coli)均有很强的抗菌作用,并且随着季铵盐在蒙脱土中的质量分数增加其抗菌活性增强.不同季铵盐改性蒙脱土的抗菌活性不同,其中双季铵盐改性蒙脱土的抗菌活性最好,对S.aereus和E coli的最小抑菌浓度分别为6.25 mg/L和12.5 mg/L.用扫描电镜对与细菌接触不同时间后的改性蒙脱土进行观察,结果表明:细菌先吸附到改性蒙脱土的表面,然后慢慢的变形死亡.同时,对在0.9%的生理盐水中浸泡不同时间后的改性蒙脱土进行X射线衍射和热重分析.结果表明:随着浸泡时间的增加,蒙脱土中的有机物质量分数及层间距均逐渐减少,说明季铵盐能从蒙脱土的层间解吸出来,并进入溶液中直接杀死细菌.因而,改性蒙脱土的抗菌活性是吸附与释放到溶液中的季铵盐离子协同作用的结果.     

TiO2包覆CaAl2O4：Eu^2＋，Dy^3＋新型复合材料的制备及性能研究

采用溶胶-凝胶法在发光材料(CaAl2O4:Eu2+,Dy3+)表面包覆了TiO2膜。研究了包覆颗粒的形貌、结构和发光性能。对包覆颗粒进行了光催化实验,并对其发光机理做了初步的探讨。     

抗菌水性乳胶漆制备及其性能研究

先采用离子交换法将十二烷基二甲基苄基氯化铵插层到钠基蒙脱土中制备了复合抗菌剂,再将其加入水性乳胶漆中制备了抗菌水性乳胶漆。当成膜物质为硅丙乳液、抗菌剂的添加量为1.0W t%时,该乳胶漆的主要检测项目都达到国标规定的的技术指标,其对大肠杆菌和金黄色葡萄球菌的抗菌率均大于99%,长霉等级为0级,且水浸泡后抗菌防霉性能没有明显下降,显示长效抗菌防霉性能。     

晶种法制备单分散的金纳米粒子及光学性能研究

加入聚乙烯吡咯烷酮(PVP)做稳定化试剂,用硼氢化钾还原氯金酸,结合晶种生长法制备了单分散性、粒径小的胶体金。通过晶种生长法,在反应中加入PVP试剂,用抗坏血酸做还原剂,制备了单分散的金纳米棒。结果表明,PVP试剂对金纳米粒子的形貌有重要的影响;加入PVP试剂得到的金纳米粒子(胶体金和金纳米棒)分散性好,无明显的团聚现象。应用透射电镜,纳米粒度分析仪和紫外-可见分光光度计对不同粒径的纳米金进行了表征。     

纳米晶富铈稀土储氢合金制备及电化学性能

通过双辊快淬法制备的AB5型富铈稀土储氢合金,经X射线衍射(XRD)、扫描电镜(SEM)以及元素分析(ICP),表明该合金具有纳米晶结构,其组成成分为La0.37Ce0.41Pr0.1Nd0.12Ni4.0Co0.45Mn0.3Al0.25.同时对合金电化学性能以及循环性能进行了表征,在100mA/g放电比容量为295mA·h/g,用300 mA/g充放电120次循环后,容量衰减仅为4.8%.