十六烷基三甲基溴化铵对脱水四环素和异四环素荧光增强作用研究

在不同pH值的标准缓冲溶液及不同表面活性剂十六烷基三甲基溴化铵（CTMAB）浓度的胶束溶液环境中，研究了CTMAB对盐酸四环素的降解产物脱水四环素和异四环素的荧光强度的影响。结果表明，CTMAB对脱水四环素和异四环素具有荧光增强作用，荧光增强幅度与介质的pH值和CTMAB浓度有关，在中性和碱性条件下对脱水四环素荧光增强作用较大，在pH=9.2的条件下可使异四环素的荧光强度达到最大值，CTMAB对脱水四环素和异四环素的这种荧光增强作用，为建立较灵敏的盐酸四环素及其降解产物的荧光定量方法提供了依据。     

表面活性剂对HPTS荧光的单分子猝灭及胶束作用

研究了各种表面活性剂存在下,8-羟基-1,3,6-三磺酸芘钠盐(HPTS)的荧光光谱,结果表明、表面活性剂对其荧光特性的影响可分为两种类型:单分子猝灭(CMC以下)和胶束作用(CMC以上)。它们分别服从相应的Stern-Volmer稳态猝灭和溶质-胶束作用线性方程。按导出方程对应作图,求得CTMAB的单分子猝灭常数K=2.4×10~5L/mol;CTMAB胶束和TX100胶束对HPTS的键合常数分别为7.4×10~5L/mol和7.0×10~3L/mol。阴离子表而活性剂十二烷基硫酸钠,由于其电性与HPTS阴离子电性的不相容性,对HPTS荧光未见明显影响。     

胶束体系中荧光素与四溴荧光素间能量转移条件及模型研究

研究了阳离子表面活性剂(CSAA)在水溶液中与阴离子酸性染料四溴荧光素(TBF)的荧光反应,发现当CSAA单体与TBF形成离子缔合物时,TBF的荧光发生猝灭,而CSAA胶束与TBF作用又会产生一个新的、更强的荧光。进而研究了阳离子表面活性剂CTMAB及CPB胶束体系中酸性阴离子荧光染料荧光素与四溴荧光素间的能量转移条件。表明只有在带相反电荷的CSAA形成的胶束中,阴离子染料间的能量转移才可能发生,在2/3临界胶束浓度(CMC)时能量转移效率达到最大。并推测了胶束体系中染料间能量转移模型及染料间能量转移的一般规律。     

荧光胺与芳伯胺衍生反应的介质效应

研究了ｐＨ多种有机溶剂及其用量，表面活性剂，环糊等介质环境对荧光胺与对氨基苯磺酸衍生反应及其产物荧光特性的影响，该衍生反应需要有机溶剂，多种有机溶剂均可使用，但用量宜少，所试验的各类表面活性剂中。仅ＴｒｉｔｏｎＸ－１００有显著的增敏作用，且其增敏效应受有机溶剂用量的影响，显示出明显的竞争效应，本文还对荧光胺与对氯苯胺间的荧光衍生反应进行了对比研究。     

荧光增白剂VBL与阳离子Gemini表面活性剂溶液的光谱研究

研究了荧光增白剂VBL在阳离子Gemini表面活性剂相互作用的紫外光谱和荧光光谱.当加入表面活性剂浓度较低时,由于VBL和表面活性剂单体形成离子缔合物,紫外吸收下降,荧光发生静态猝灭;进一步加大表面活性剂的浓度到形成胶束时,由于胶束微环境的影响.使VBL的紫外吸收和荧光光谱增强;当表面活性剂的浓度远大于CMC(1.25×10-mol/L,25℃)时,这种变化趋缓.结果表明,在合适的表面活性剂浓度下.荧光增白剂VBL与阳离子Gemini表面活性剂之间存在强的相互作用.     

硫杂杯[4]芳烃基胶束自组装荧光探针的结构性质及检测性能的研究

水体中重金属污染因威胁生态环境和人类健康而被受广泛关注。荧光探针由于具有快速高效检测重金属的特性，一直是该领域的研究热点。通常，荧光探针在结构上包括对待测物质起识别作用的受体和能产生信号响应的荧光体，并逐步形成了内在型、共轭型、系综型和模板辅助自组装型等四种结构类型。近年来，基于受体和荧光体在表面活性剂胶束内自组装而形成的胶束自组装型荧光探针因结构简单、易于制备、能直接应用于水环境等特点逐渐受到重视。以对铜离子具有优异结合性能的对叔丁基硫杂杯[4]芳烃（TCA）为受体，以芘、荧蒽、蒽、菲、苝等分子为荧光体，通过表面活性剂胶束自组装制备针对Cu2+检测的胶束自组装型荧光探针，采用参比法测定了胶束自组装荧光探针的荧光量子产率，采用稳态荧光法测定了胶束聚集数，同时通过计算荧光猝灭率分别考察了荧光体种类、复配表面活性剂等因素对该探针的Cu2+检测性能的影响情况。实验结果显示，采用十二烷基硫酸钠（SDS）、曲拉通100（TX-100）、聚氧乙烯月桂醚（Brij35）等三种不同的表面活性剂对探针荧光体的荧光量子产率产生了明显影响，测得的荧光探针荧光量子产率介于0.25~0.47，且三者逐渐增大，说明表面活性剂改变了胶束内荧光分子芘所处微环境的极性，且不同类型表面活性剂对微环境极性的影响程度有所差异，微环境极性的增强对极性更大的激发态芘具有更强的稳定作用。而受体TCA的加入对荧光体所处微环境极性影响较小，未对荧光量子产率产生较大影响。但TCA的加入使探针的胶束聚集数明显减少，这归因于具有两亲性的受体TCA分子通过胶束自组装进入并分散在表面活性剂分子层中，形成共胶束结构，从而改变了表面活性剂分子的聚集状态。荧光体变更对荧光探针的Cu2+检测性能有显著影响，在同样条件下，以荧蒽、蒽、菲作为荧光体的探针检测Cu2+所得到的荧光猝灭率远高于芘、苝，这主要是因为不同荧光体在从激发态返回基态时辐射跃迁所释放能量不同，其能量与受体TCA识别Cu2+所需能量之间的匹配度越高，荧光猝灭率越大。不同类型的表面活性剂之间的复配能明显提升荧光探针检测性能，当非离子/阴离子、非离子/阳离子型复配表面活性剂之间的复配比例分别为7∶3和1∶1时荧光猝灭率达到最大值，且均高于单一表面活性剂时的荧光猝灭率。这说明不同类型表面活性剂复配的最佳比例存在较大差异，但均有效地增强了受体与荧光体的分散性及自组装性能，提高了对Cu2+的检测性能。研究结果将为新型胶束自组装荧光探针的设计和应用提供数据参考。     

表面活性剂对空气-乙炔火焰原子吸收法测定铝的增感效应研究

研究了溴化十六烷基三甲基胺、氯化十六烷基吡啶等10种表面活性剂对测定铝时的增感效应.结果表明,在实验所选择的表面活性剂中,阳离子表面活性剂对铝有明显增感作用,阴离子表面活性剂对铝有抑制作用,而特殊表面活性剂对铝没有作用.以溴化十六烷基三甲基胺(CTMAB)为增感剂,研究了空气-乙炔火焰原子吸收法测定铝镍合金样品中铝的工作条件、CTMAB用量、溶液介质和浓度及共存离子干扰的影响.测定铝的线性范围为0.10～2.0 g·L-1,方法的相对标准偏差为2.6%,标准加入回收率在97%～103%之间.     

稳态荧光探针法测定Tween系列非离子表面活性剂临界胶束浓度

以芘为荧光探针,测定了不同条件下的Tween系列表面活性剂增溶芘后的稳态荧光光谱,建立了Tween非离子表面活性剂的临界胶束浓度(CMC)的测试方法,研究了影响非离子表面活性剂临界胶束浓度的因素。根据I338/I333与Tween浓度的变化关系,可得到Tween20、40、60、80的临界胶束浓度分别为5.1×10-5、3.7×10-5、3.1×10-5、8×10-6mol/L。结果表明,同系列的非离子表面活性剂的分子结构对其临界胶束浓度有一定影响。同时,制备温度和外部添加的试剂如无机盐、乙醇、丙三醇均影响其临界胶束浓度。     

钨-3,5二溴水杨基荧光酮-CTMAB-Tween80多元配合物的分光光度法研究

在混合表面活性剂溴化十六烷基三甲铵 (CTMAB)和吐温 80 (Tween80 )存在下 ,研究了 3,5 二溴水杨基荧光酮 (DBSAF)与钨 (Ⅵ )显色反应的光度特性。在 0 6 0mol·L-1HCl介质中 ,钨 (Ⅵ )与DBSAF及表面活性剂形成胶束络合物 ,采用混合表面活性剂使增溶增敏作用更为显著 ,络合物表观摩尔吸光系数ε =2 6 4× 10 5L·mol-1·cm-1,λmax =5 2 7nm。用摩尔比法和连续变换法测得钨 (Ⅵ )与DBSAF所形成的络合物化学计量比为 1∶2。钨 (Ⅵ )含量在 0～ 4 0 0 μg·L-1范围服从比尔定律 ,拟定分析方法可直接用于合金钢样品中微量钨的测定     

Spectral Properties and Solubilization Location of 2''-Ethylhexyl 4-(N,N-Dimethylamino)benzoate in Micelles

在阳离子、非离子和阴离子表面活性剂胶束溶液中，研究了4-(N,N-二甲氨基)苯甲酸2'-乙基己基酯(EHDMAB)的双重荧光和紫外吸收．当EHDMAB增溶在不同的胶束溶液中，紫外吸收增强，在离子型胶束溶液中，可观察到具有较长波长的EHDMAB分子内扭转电荷转移(TICT)荧光，相反，在非离子型胶束溶液中，可观察到具有较短波长TICT荧光，特别是位于阳离子胶束Stern层中的吡啶阳离子可强烈猝灭EHDMAB分子的双重荧光，所吸收的紫外辐射主要通过TICT荧光和非辐射去活化衰减．按照EHDMAB分子TICT荧光在有机溶剂中的极性依赖性，EHDMAB分子的4-(N,N-二甲氨基)在离子型胶束和非离子型胶束中处于不同的极性环境；根据EHDMAB和表面活性剂分子的结构和大小分析，EHDMAB分子的4-(N,N-二甲氨基)应朝向胶束的极性头基团，而2'-乙基己基链则朝向疏水性的胶束内核．动态荧光猝灭测量为EHDMAB分子在不同胶束中的位置进一步提供了佐证．     

A thermodynamic and photophysical study of the effects of thiourea on the micellar properties of aqueous sodium dodecyl sulphate solution

The micellar properties of sodium dodecyl sulphate (SDS) in aqueous thiourea solutions were investigated with the aim of studying the effect of thiourea on these properties. The critical micelle concentrations (cmc) and the degree of dissociation of the micelle were determined by the conductometric method over the temperature range 298–323 K for different concentrations of thiourea. The cmc values of the surfactant in the presence of thiourea were obtained by following the change in the relative intensities of vibrational fine structure of the pyrene fluorescence spectra. The aggregation numbers were determined by employing the static quenching fluorescence method. The cmc values in the presence of varying electrolyte concentrations (NaCl) were obtained with 8-anilinonaphthalene 1-sulphonate (ANS) as a fluorescence probe, and from these values the degree of dissociation was calculated. The mass action model was applied in the present study to obtain various thermodynamic parameters of micellization. All these properties were compared with the micellar properties of an aqueous urea/SDS system, and it was found that thiourea is a better demicellization agent.     

Effect of surfactants on the aggregation of pyronin B and pyronin Y in aqueous solution

Molecular dynamics of pyronin B (PyB) and pyronin Y (PyY) in aqueous solution containing different surfactants were investigated by using absorption and fluorescence spectroscopy techniques. First, the interactions of PyB and PyY with the negatively charged surfactant sodium dodecyl sulphate (SDS) were investigated in the below and above critical micelle concentration (cmc). The H-aggregate formation of the dye compounds was observed for below the cmc of SDS surfactant. The absorbance of H-aggregate absorption band of PyB and PyY decreased according to the aggregate-monomer equilibrium by increasing SDS surfactant concentration towards the cmc. Therefore, equilibrium constants of the aggregate formation and oscillator strengths of monomer and aggregate of the dye compounds were calculated from spectral studies. Moreover, aggregate formation dynamics was discussed in terms of thermodynamic functions by using temperature studies. The interactions of PyB and PyY with the positively charged hexadecyltrimethylammonium bromide (CTAB) and neutral Triton X-100 (TX-100) were also studied and it was observed that there was no aggregate formation on the absorption and fluorescence spectra for below and above the cmc.     

环丙沙星的光谱性质、质子化作用与荧光量子产率

研究了环丙沙星(ciprofloxacin,CIP)在不同pH条件下的荧光光谱、紫外吸收光谱和质子化作用,测量了CIP在中性条件下的荧光量子产率。在H+浓度大于1mol·L-1的HCl介质中,CIP分子(简写为HL)可以结合3个质子而以H4L3+形式存在,有微弱的荧光,最大荧光发射波长(λmax)为456nm。在pH0～2的酸性条件下,CIP主要以H3L2+形式存在,λmax为450nm,荧光较弱,荧光强度随pH的升高而上升。在pH2～4时,CIP主要以H2L+形式存在,具有强荧光,λmax仍为450nm。当pH>4时,λmax逐步蓝移到414nm,荧光强度随pH的升高而稍有降低,同时紫外吸收光谱也有明显变化,表明H2L+随pH升高而失去质子,以双极离子HL形式存在。当pH>8时,荧光强度随pH升高而减弱至消失,表明HL逐步失去质子,转化为无荧光的阴离子L-。在分子形态变化过程中,最大荧光激发波长始终在275nm附近,但最大荧光发射波长有较大变化。在pH7.0的缓冲溶液中,以硫酸奎宁为参比,测得CIP在最大荧光激发波长275nm处的荧光量子产率为0.12。     

Molecular simulations of self-assembly processes of amphiphiles in dilute solutions: the challenge for quantitative modelling

We report on two recent developments in molecular simulations of self-assembly processes of amphiphilic solutions. We focus on the determination of micelle formation of ionic surfactants which exhibit the archetype of self-assembling compounds in solution. The first approach is centred on the challenge in predicting micellisation properties through explicit solvent molecular dynamics simulations. Even with a coarse-grained (CG) approach and the use of highly optimised software packages run on graphics processing unit hardware, it remains in many cases computationally infeasible to directly extract the critical micelle concentration (cmc). However, combined with a recently presented theoretical mean-field model this task becomes resolved. An alternative approach to study self-assembly is through implicit solvent modelling of the surfactants. Here we review some latest results and present new ones regarding capabilities of such a modelling approach in determining the cmc, and the aggregate structures in the dilute regime, that is currently not accessible through explicit solvent simulations, neither through atomistic nor through CG approaches. A special focus is put on surfactant concentration effects and surfactant correlations quantified by scattering intensities that are compared to recently published small-angle X-ray scattering data.     

Synthesis and optical properties of a new lipophilic derivative of rhodamine B1

In this paper, a new rhodamine B lauryl amine (RBL) lipophilic derivative was synthesized by amidation of phenyl carboxylic group of RB with lauryl amine, and then its optical properties were studied on different conditions, such as varied excitation wavelengths, different kinds of solvents, pH values, etc. The results show that the absorption and emission spectra are significant different with the different structures of RBL. The absorption intensity of RBL in solvents with weak acidic proton was stronger than that in aprotic solvent because the former one can form hydrogen bond and thus stabilize the opened form of RBL. The fluorescence emission of RBL in dichloromethane and ethanol was stronger than that in acetone, tetrahydrofuran and water. It indicated that most of RBL molecules were in opened form in dichloromethane and ethanol, but in closed form in acetone, tetrahydrofuran and water. Finally, the influence of pH values was studied, and found that the intensity and position of absorption and emission peaks were almost the same in the whole acidic range, but changed a lot in alkaline medium.     

微乳液介质中镓的荧光光度光谱行为的研究与应用

研究了十六烷基三甲基溴化铵(CTMAB)微乳液介质中,镓与三甲氧基苯基荧光酮的荧光光谱行为,在pH 4.95的缓冲溶液中,镓含量在0～0.045μg·mL-1范围内与荧光强度的变化呈良好的线性关系,检测限为1.2 ng·mL-1.采用乙酸丁酯进行萃取分离,消除共存离子的干扰,能显著提高方法的选择性和灵敏度.该方法已成功用于矿石样品中痕量镓的测定.     

多组分水溶液中的石油磺酸盐与OP—10的荧光发射光谱

含苯氧基的非离子型和阴离子型表面活性剂在一定激发波长下可发出特定波长的荧光，在稀溶液中荧光发射强度与其浓度成正比，不受溶液里存在的其他物质的影响，在适当条件下相互之间也无影响。本文报道了用荧光检测复合驱油体系中的ＯＰ１０、石油磺酸盐和ＯＰ１０＋石油磺酸盐的结果。此法选择性高，灵敏度高，操作简便，可望用于复合驱油体系中表面活性剂的分析、研究。     

咖啡酸及其衍生物光谱特性研究

研究了不同pH值条件下 ,咖啡酸类化合物溶液的荧光及紫外光谱特性。实验结果表明 :咖啡酸类化合物有很宽的pH发光范围 (2～ 1 2 ) ,发光强度、光谱形状及峰位随pH值不同而异 ,且在pH =9～ 1 0时 ,咖啡酸类化合物荧光强度最强。研究还发现 :咖啡酸类化合物 4 位酚羟基的解离可导致荧光强度显著增强 ,而 3 位酚羟基的解离可能会导致荧光猝灭 ,并且在强酸和强碱介质中发射荧光均被显著猝灭 ;此外 ,在强碱性介质中紫外光谱形状有很大变化 ,表明咖啡酸类化合物在强碱性下分子结构发生了明显改变。