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稳态荧光探针法测定临界胶束聚集数 总被引:32,自引:0,他引:32
以芘为荧光探针、二苯甲酮为猝灭剂,用稳态荧光探针法测定了SDS和AS的胶束聚集数(Nm).以芘的饱和水溶液为溶剂配制表面活性剂溶液,二苯甲酮的适宜浓度取小于1.00 mmol•L-1时,可以获得满意的实验结果.当表面活性剂溶液浓度为5~9倍cmc时,Nm随表面活性剂浓度增大而线性增大,而随温度的变化略有波动.cSAA=cmc时,Nm值为一本征值,定义为临界胶束聚集数[Nm].[Nm]值可从Nm-cSAA实验曲线外延得到.25℃时SDS的临界胶束聚集数[Nm]为57;40℃时SDS的[Nm]为49,AS的[Nm]为55. 相似文献
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荧光和动态光散射方法研究两性表面活性剂胶束的聚集和相互作用 总被引:4,自引:0,他引:4
以芘为荧光探针、二苯酮为猝灭剂,利用荧光方法测定了两性表面活性剂N-十二烷基-N,N-二甲基氨基丙磺酸盐(DDAPS)胶束在不同温度和不同NaCl浓度下的聚集数。利用动态光散射方法得到了胶束的水力半径Rh.结果表明,DDAPS的胶束聚集数和Rh值随NaCl浓度的升高略有增大;随温度的升高而稍有下降。DDAPS胶束之间的作用力以排斥力为主。 相似文献
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We developed a new method to measure the average aggregation number of large rod-like micelles using static fluorescence self-quenching of a solubilized fluorophore. The method is based on the increase of self-quenching of micelle-solubilized pyrene through excimer formation. We consider the effect of random distribution of pyrene in micelles and the micellar size distribution. The measured average aggregation <n> M is based on a new M-weighted raging similar to our exponential-weighted averaging in the transient decay method. We apply this method to study the effect of a large concentration of salt on the average aggregation behavior of sodium dodecyl sulfate (SDS) and cetyle tetraammonium bromide (CTAB). The sizes increase with increasing ionic concentrations. For SDS, we used the thermodynamic model developed by Missel et al. to calculate < n > M which we compare with experimental results. 相似文献
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稳态荧光探针法测定三聚季铵盐表面活性剂的胶束聚集数 总被引:5,自引:0,他引:5
以芘为荧光探针, 十六烷基氯化吡啶(CPC)为猝灭剂, 以芘的饱和水溶液为溶剂配制表面活性剂溶液, 根据芘的荧光强度之比I1/I3随表面活性剂水溶液浓度的变化, 测定了三聚季铵盐表面活性剂CTTTA的cmc值, 测定值与表面张力法测定的cmc值一致;当猝灭剂CPC的浓度取0.1~0.3 mmol·L-1范围时, 用稳态荧光探针法测定了CTTTA的胶束聚集数. 实验数据表明, 表面活性剂溶液浓度为6~10倍cmc时, 胶束聚集数N随表面活性剂浓度增大而线性增大, 并用外推法得到CTTTA的临界胶束聚集数. 相似文献
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《Journal of Dispersion Science and Technology》2013,34(4):323-328
The fluorescence characteristics of 2-methyl naphthalene have been studied in ionic micelles of sodium dodecyl sulphate (SDS) and cetyl trimethyl ammonium bromide (CTAB) and in nonionic micellar medium of p-t-octylphenyl polyethoxyethanol (Triton X-100). The fluorescence quenching of fluorophore by halides and pseudohalide obeys the Stern-Volmer Equation up to a certain concentration of quencher. A quenching sphere of action model has been considered to explain the deviations from Stern-Volmer behaviour. The distribution of quenchers in the micellar phase has been calculated. 相似文献
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空间分辨荧光分析技术 总被引:1,自引:0,他引:1
空间分辨荧光分析技术突破了传统荧光分析的局限,为获得空间定位信息提供了技术保障。系统地综述了构成该技术的共焦荧光法、全内反射荧光法、多光子荧光法以及近场荧光法等4种方法的原理、特点、发展及其应用,并且强调了其在单分子测定中的作用。引用文献64篇。 相似文献
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《Analytical letters》2012,45(20):1633-1645
Abstract The effects of micelles on the fluorescence detection of phenolic compounds are described. Micelles were found to enhance the fluorescence of the drugs apomorphine (APO), and N-n-propylnorapomorphine (NPA), and a series of model hydroxybiphenyls. The fluorescence enhancements were pH dependent and biphasic behavior in hexadecyltrimethylamnonium chloride was observed for APO and NPA. Multiple equilibria and formation of zwitterions of the phenolic aporphines in the micellar environment is proposed to explain this behavior. Micellar fluorescent enhancements should be useful in improving the sensitivity of fluorometric determinations of polar compounds. 相似文献
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聚集导致的荧光增强与双分子膜上能量转移吴立新,郑惠(吉林大学理论化学研究所,长春,130023)(吉林粮油食品专科学校)梁映秋(南京大学化学系)关键词聚集,双分子膜,荧光增强,能量转移在模拟生物膜功能研究中,以表面活性剂聚集体系为模拟剂研究其自组织行... 相似文献
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离子选择电极法测定胶团的反离子结合度 总被引:2,自引:0,他引:2
胶团的反离子结合度(K)对于胶团各种性质的研究是一个至关重要的参数[1~3]。已有不少方法用于K值的测定,其中以离子选择电极法最为方便[4~8],且此法赋予K值的含义也与热力学要求相同[9]。 相似文献
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《Analytical letters》2012,45(7):379-385
Abstract A fluorescence quenching method for the determination of fluoride ion over the concentration range from 10?9 to 10?6M is presented. The fluoride ion is added to the fluorescent chelate of aluminum(III) and PAN [1- (2-pyridylazo)-2-naphthol]: the fluoride preferentially complexes the aluminum (III), displacing nonfluorescent PAN. Of the anions tested as possible interferences at equimolar levels, phosphate interferred seriously and iodide interferred somewhat. 相似文献
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The photophysical property of the tricarbocyanine dye IR144 has been extensively studied in non‐aqueous solvents. However, as a potential near‐infrared biomedical imaging probe, the photophysical property of IR144 in water is still little known. So, the aggregation behaviors of IR144 in water with steady‐state absorption spectroscopy and integrated polarization dependent femtosecond pump‐probe spectroscopy were investigated. Through comparing the absorption spectral bandshape of IR144 in water and in water pool of AOT reverse micelles, It is found that IR144 form dimer aggregates in water even at very low concentration (<1.0×10?7 mol·L?1). And the absorption spectrum of the IR144 aggregates always displays a bimodal feature, which is independent of the dye concentration ranging from 1.0×10?7 to 1.0×10?4 mol·L?1. For better understanding the aggregation behaviors of IR144 in water, we measured the ground state recovery kinetics and the reorientation kinetics of IR144 in water and in water pool of AOT reverse micelles (W0=[H2O]/[AOT], W0=40). It is found that the fluorescence quantum yield of IR144 in water is lower than that in water pool of AOT reverse micelles, and the reorientation time of IR144 in water is slower than that in water pool of AOT reverse micelles. Those kinetic measurements also verify that IR144 exists as dimer aggregates in water. 相似文献
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We have investigated the effect of salt concentration and temperature on the average aggregation number and micro-polarity of the interior of micelles of sodium dodecyl sulfate (SDS). sodium tetradecyl sulfate (STDS) and lithium dodecyl sulfate (LiDS). The transient fluorescence decay of micelle-solubilized pyrene has been measured and analyzed. An exponent weighted average aggregation number <n>e was obtained by this technique. For SDS and STDS in NaCl solution, <n>e increases as the temperature is lowered or salt concentration is increased <n>e increased from ~ 50 to ~ 250 over [NaCl] = 0 to 0.8 M. Due to the strong counterion binding of lithium in the micellar solution, the LiDS micelle is much, smaller and does not increase appreciabily even at [LiCl] =0.8 M. From the fluorescence spectrum fine structure of pyrene and the fluorescence decay of the monomer and excimer, we can understand the local polarity and the water penetration to the interior of the micelle upon addition of salts and with changing temperature. The interior of the micelle becomes more nonpolar as the salt concentration is increased and the temperature is lowered. A complete kinetic analysis of the time–dependence of the fluorescence is given. The kinetic analysis is in agreement with the results reached by fluorescence spectral analysis. 相似文献
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新型聚合物胶束电动色谱法分离5种植物激素 总被引:1,自引:0,他引:1
随着植物激素的滥用及使用不当导致的食品安全问题逐渐增多,加强食品中植物激素的痕量检测显得日益重要。本研究制备了具有两亲性的聚(甲基丙烯酸苄基酯-甲基丙烯酸)胶束,成功地将5种植物激素分离,建立了一种植物激素痕量检测的聚合物胶束毛细管电动色谱方法,本方法高效、快速、重现性好。经过优化,得到了最佳色谱条件:2 g/L聚合物胶束,50 mmol/L Na OH-H3BO3缓冲液(p H 9.2);运行电压15 k V。采用此方法分析实际样生根粉溶液,成功检测到萘乙酸。 相似文献
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《Analytical letters》2012,45(11):835-844
Abstract The fluorescent analogue 8-hydroxy-1,3,6-pyrene-trisulfonate is known to bind to the 2,3-diphosphoglyceric acid binding site of deoxy hemoglobin. We have used this property to monitor temperature dependent changes in concentrated solutions of deoxy hemoglobin S. By monitoring the polarization of fluorescence from the bound fluorophore, we have been able to demonstrate that the polarization of fluorescence goes through a temperature maximum analogous to that which has been observed with temperature versus viscosity measurements when following aggregation of deoxy hemoglobin S. Results of experiments with deoxy hemoglobin A and deoxy hemoglobin S suggest that difference in aggregation may be related more to quantitative differences than to qualitative differences. 相似文献
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荧光信号对环境变化的敏感程度主要取决于其产生本源。一般而言,聚集诱导激基缔合物荧光对其所处微环境变化异常敏感,因而引起了荧光传感器研究领域学者的高度关注。除此之外,荧光传感器的传感性能还与其所采用的荧光物种的类型和传感元素的结构密切相关。基于这些认识,本文概括介绍了笔者实验室多年来以聚集诱导激基缔合物荧光为基础的荧光传感器研究进展,特别是以芘为例,系统介绍了该类传感器在液相或气相中的检测应用,其中部分传感器已经实现了仪器化。同时,还介绍了由本课题组提出的用于理解荧光薄膜传感器传感机理和指导新型传感薄膜设计的"二维溶液模型"。最后,展望了荧光传感器研究和应用前景,指出了此类研究面临的主要挑战。 相似文献