共查询到19条相似文献,搜索用时 62 毫秒
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一种Q态纳米CdS的新型制备法——聚合物分散法 总被引:6,自引:0,他引:6
采用一种Q态CdS的新型制备法——聚合物分散法, 即用水溶性聚合物溶液作为分散剂, 用2-巯基乙醇(或十二硫醇)作表面修饰剂, 在聚合物网络中构筑出四种粒径的、单分散性的Q-CdS. 通过UV-Vis光谱和TEM考察了Q-CdS的粒径及分布情况, 并用FL光谱研究了不同尺寸的Q-CdS的荧光性能. 结果表明, 采用聚合物分散法可以方便、快捷地得到粒径小且分布窄的Q-CdS纳米粒子, 这些粒子在紫外光谱及荧光光谱上均表现出明显的量子尺寸效应. 相似文献
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Pt/CdS光催化剂表面修饰和表面结构 总被引:1,自引:0,他引:1
Pt/CdS光催化剂表面修饰和表面结构张虎勤陈开勋*金振声(西北大学化工系西安710069)(中国科学院兰州化学物理研究所兰州)关键词光催化剂,半导体,表面组成,表面修饰1996-05-20收稿,1996-09-28修回近年来对在Pt/CdS催化剂上... 相似文献
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用硫脲分子表面修饰的CdS纳米粒子的合成和表征 总被引:15,自引:0,他引:15
报道了用硫脲分子进行表面化学修饰的CdS纳米粒子的合成方法,并引入了AOT(磺基琥珀酸双-2-乙基己基酯钠盐)作为平衡反离子,进一步对CdS表面作了修饰,增加了CdS纳米粒子在有机溶剂中的稳定性和可分散性。我们还探讨了温度、浓度、pH等因素对合成的影响,并通过TEM、XRD、FT-IR等手段对产物结构进行了表征。所得微粒粒径为5 nm左右,呈球形,硫脲分子与CdS纳米粒子富Cd2+表面通过形成Cd-S配位键而修饰在粒子表面。这种表面修饰的CdS纳米粒子将在非线性光学及自组装方面具有优 相似文献
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荧光纳米晶制备及其与聚合物的复合组装 总被引:1,自引:0,他引:1
纳米尺寸无机晶体(纳米晶)具有特殊的光、电和磁等性能, 但这类材料通常以胶体溶液或固体粉末的状态存在, 稳定性和分散性较差. 实现这类材料的应用, 需要将其与一些惰性介质复合, 从而提高稳定性和加工性. 聚合物材料作为一种有机惰性介质, 具有良好的材料兼容性和可加工性, 是稳定纳米晶材料的首选介质. 此外, 很多聚合物材料本身也具备特殊的性能, 可以对纳米晶性能进行有益的补充和调节. 因此, 功能纳米晶材料与聚合物复合, 将成为开启材料性能宝库的钥匙. 我们研究组结合自己的相关研究, 系统总结了荧光纳米晶材料与聚合物的复合组装方法, 着重阐述不同方法的优势及意义, 希望对从事这一前沿领域研究的人们有所启发. 相似文献
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基于表面修饰聚丙烯酸合成超顺磁/荧光纳米复合粒子 总被引:3,自引:1,他引:3
在聚丙烯酸修饰的Fe3O4纳米粒子表面共价结合罗丹明B, 获得分散性和荧光信号均得到改善的超顺磁/荧光复合纳米材料. 分别用透射电子显微镜(TEM)、傅里叶变换红外光谱仪(FTIR)、热重分析仪、荧光光谱仪、X射线衍射仪(XRD) 和振动样品磁强计(VSM) 对合成的粒子进行了表征. 结果表明, 羧基化的Fe3O4纳米粒子和Fe3O4-荧光纳米复合材料的粒径基本相同, 为6~10 nm. Fe3O4-荧光纳米复合材料的饱和磁化强度为39.2 A•m2/kg, 室温下呈现超顺磁性, 具有较强的荧光信号. 相似文献
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胃蛋白酶对CdTe纳米粒子的表面修饰及分析应用 总被引:1,自引:0,他引:1
以巯基乙酸为稳定剂和表面修饰剂, 在有机相中合成了平均粒径为3 nm左右的CdTe纳米粒子, 用胃蛋白酶改变纳米粒子的表面修饰状态并研究其系列特性. CdTe纳米粒子在320 nm处有强的紫外吸收, 在524.8 nm处有荧光发射. 经胃蛋白酶对其表面修饰后, 紫外吸收峰位不变, 但吸光强度升高, 荧光峰位蓝移至467.2 nm, 荧光强度降低. 温度、pH值及离子强度均对表面修饰产生影响. 在最佳实验条件下, 胃蛋白酶质量浓度在4—40 mg/L范围内与荧光降低值之间呈线性关系, 检测限(3σ)为0.28 mg/L(n=10), 该方法已被用于人体胃液胃蛋白酶的测定. 相似文献
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医用高分子材料表面的润滑改性进展 总被引:4,自引:0,他引:4
综述了医用高分子材料表面的润滑改性方法,对影响表面润滑性的因素进行了讨论,简述了材料表面润滑性的测定方法,润滑机理及润滑表面的形态,概述了表面润滑的医用高分子材料在临床中的应用。 相似文献
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An ascorbic acid (AA) sensor was constructed based on the fluorescence resonance energy transfer (FRET) between CdS quantum dots (CdS QDs) and polydopamine (PDA) to detect trace AA sensitively. FRET occurred due to the broad absorption spectrum of PDA completely overlapped with the narrow emission spectrum of CdS QDs. The fluorescence of CdS QDs was quenched and in the “off” state. When AA was present, the conversion of DA to PDA was hindered and the FRET disappeared, resulting in the fluorescence of CdS QDs in an “on” state. Importantly, the degree of fluorescence recovery of CdS QDs displayed a desirable linear correlation with the concentration of AA in the range of 5.0–100.0 μmol/L, the linear equation is , and the detection limit is 1.16 μmol/L (S/N = 3, n = 9). There was almost no interference with common amino acid, glucose and biological sulfhydryl small molecules to AA. Trace amount of AA in vitamin C tablets were determined and satisfactory results were obtained; the recoveries were observed to be 98.01–100.7%. 相似文献
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Preparation,morphology, size quantization effect and photocatalytic properties of CdS Q-nanocrystals
Intercommunity of lots of molecules and perturbation of few molecules have been shown in bulk materials because the intermolecular force is very much smaller than that of intramolecules. So, macroscopic solid theories have been applied to investigating their properties. On the other hand, microscopic quantum mechanical theory (or molecular orbital theory) has enabled the study of single molecule. However, it becomes much more complicated to the study on the small-parti- cle species representin… 相似文献
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CdS quantum dots (QD) were capped with SiO2 via a microemulsion method for reducing the toxicity and imparting the biocompatibility of the CdS QD. The resulting CdS/SiO2 core/shell nanoparticles (NP) showed an improved water‐solubility and stability even in pH 4.0 acidic medium. Their fluorescence could be effectively enhanced in the presence of bovine serum albumin (BSA), due to the passivation effect of BSA on the surface of the NP. Furthermore, the concentration dependence of the fluorescence intensity obeys the Langmuir‐type binding isotherm. Thus a novel fluorescence enhancement method for the determination of BSA has been developed using the less‐toxic CdS/SiO2 core/shell NP as probes. Under optimal conditions, the linear range of calibration curve is 0.6–30 µg·mL?1, and the detection limit is 0.18 µg·mL?1. Compared with the water‐soluble CdS NP without SiO2 shell, the CdS/SiO2 core/shell NP exhibited slightly lower fluorescence response to BSA as well as other coexisting substances, such as heavy and transition metals, due to the inhibition of SiO2 shell. The proposed method was applied to the quantification of BSA in synthetic and serum samples with satisfactory results. 相似文献
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Dr. Maria J. Ruedas‐Rama Dr. Angel Orte Prof. Elizabeth A. H. Hall Prof. Jose M. Alvarez‐Pez Dr. Eva M. Talavera 《Chemphyschem》2011,12(5):919-929
Semiconductor nanocrystals, namely, quantum dots (QDs), present a set of unique photoluminescence properties, which has led to increased interest in using them as advantageous alternatives to conventional organic dyes. Many applications of QDs involve surface modification to enhance the solubility or biocompatibility of the QDs. One of the least exploited properties of QDs is the very long photoluminescence lifetime that usually has complex kinetics owing to the effect of quantum confinement. Herein, we describe the effect of different surface modifications on the photoluminescence decay kinetics of QDs. The different surface modifications were carefully chosen to provide lipophilic or water‐soluble QDs with either positive or negative surface net charges. We also survey the effect on the QD lifetime of several ligands that interact with the QD surface, such as organic chromophores or fluorescent proteins. The results obtained demonstrate that time‐resolved fluorescence is a useful tool for QD‐based sensing to set the basis for the development of time‐resolved‐based nanosensors. 相似文献