Raman光谱方法研究三氯甲烷与苯分子间的 C/H···π相互作用

测量了不同浓度三氯甲烷(CHCl₃)与苯(C₆H₆) 二元溶液的Raman光谱,随C₆H₆浓度的增加, 受分子间C/H···π相互作用的影响, CHCl₃中C-H键伸缩振动频率向低波数移动;当 CHCl₃体积分数小于40%, C-H键伸缩振动频率不变, 分子间C/H···π相互作用达到饱和.分别以 CHCl₃和 C₆H₆体积分数为70%的 CHCl₃-C₆H₆混合溶液为研究对象, 测量了它们的高压和低温Raman光谱.根据 CHCl₃中C-H键伸缩振动频率随压强和温度的变化关系, 得出了分子间C/H···π相互作用对压强和温度的扰动表现出不稳定性.     

SDS胶束溶液在石油类污染物荧光光谱测量中的应用

提出了一种以十二烷基硫酸钠(SDS)胶束溶液为溶剂增溶、增敏、增稳石油类物质的新方法。研究了石油类物质的荧光强度随SDS胶束溶液浓度的变化规律,确定了其溶剂SDS胶束溶液的最佳浓度为0.1 mol·L-1。使用FLS920荧光光谱仪测量得到不同稀释浓度的汽油、柴油、煤油SDS胶束溶液的三维荧光光谱矩阵(EEMs),分析了瑞利(Rayleigh)散射、拉曼(Raman)散射以及仪器光谱特性对测量光谱的影响,经过光谱校正,建立了三种油的SDS胶束溶液在激发波长为250～400 nm、发射波长为260～500 nm范围内的三维荧光光谱图,并确定了在一定浓度范围内荧光强度与浓度具有良好的线性关系。在相同条件下,用同样的方法配制各种浓度汽油、柴油、煤油水溶液作对比,验证了SDS胶束溶液作为石油类物质的溶剂可以使水中石油类物质的溶解度增加、荧光强度增大、稳定性更好,实现了石油类物质可以不依赖于某些有毒溶剂萃取,又解决了其水中溶解度低不宜定量的问题。     

胶束形成前十二烷基硫酸钠与天青A变色机理的研究

应用光谱探针技术研究了胶束形成前十二烷基硫酸钠(SDS)与天青A(AA)相互作用的吸收光谱,比较了SDS和硫酸软骨素(CS)与AA相互作用的光谱曲线,考察了乙醇和NaCl对SDS-AA复合物吸收光谱的影响,对胶束形成前SDS与AA变色反应的机理进行了研究。研究结果表明,SDS-AA反应体系呈现蓝色→紫红色→蓝色的颜色变化,主要是由于SDS有序集合体中结合态AA分子定向聚集,形成聚集体的程度不同所造成的。依据c_SDS和ΔA₄₉₈/Δc_SDS的关系,确定了SDS水溶液的临界预胶束浓度(critical premicelle concentration,CPC),其数值为1.0×10-4 mol·L-1。     

The effect of hydration of ions of inorganic salts on the shape of the Raman stretching band of water

The shape of the Raman stretching band of water molecules in aqueous solutions of electrolytes KBr, KCl, KI, NaCl, and NaI is studied. It is confirmed that the characteristics of the stretching band strongly depend on the concentration and type of salt. The behavior of different parameters of the band is explained in terms of the theory of hydration of salts.     

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.     

用激光拉曼光谱研究液态乙醇的水合作用过程

为研究室温下乙醇-水二元混合物内部的分子间缔合情形,测得了不同体积配比溶液的拉曼光谱,发现位于2 800~3 050 cm-1波数区间的C—H伸缩振动频率随乙醇中加入水量的增加整体呈现蓝移趋势,而位于1 048 cm-1附近的CO伸缩振动频率的变化规律却与此相反。分析认为,这种现象主要由溶液内部分子间发生的不同水合作用所致,并据此阐明了液态乙醇的水合作用过程:水分子首先与纯乙醇中的自缔合短链发生氢键缔合作用,形成了含有较多乙醇分子数的乙醇水合团簇,直到溶液中水的体积含量达到50%时,乙醇的水合作用达到暂时饱和;而当水的体积含量继续增加到70%以后,水分子致使原有乙醇水合团簇解离形成较小尺寸的团簇,并与解离点位上的乙醇分子羟基发生进一步水合作用;而后,当水体积含量增至一定程度后,还会导致乙醇分子疏水基CH基团与水分子间形成弱氢键C—H…O。     

十二烷基硫酸钠(SDS)增强若丹明6G水溶液激光激发荧光谱研究

报道了若丹明6G水溶液添加不同浓度的表面活性剂十二烷基硫酸钠(SDS)时激光激发染料的变化,发现较低的掺入量导致R6G荧光减弱,适量SDS的加入使荧光增强,在5×10-5 mol·L-1的R6G水溶液中,加入6×10-2 mol·L-1 SDS,荧光增强因子达到3.1。当R6G浓度为1×10-4 mol·L-1时,加入2×10-2 mol·L-1,染料激光阈值显著降低。测量了不同浓度的R6G溶液的吸收光谱及加入不同浓度SDS后的荧光谱,分析了不同SDS加入量下R6G荧光减弱及增强的物理机制。     

不同水质的拉曼光谱研究

测量了不同浓度杂质水的拉曼光谱的,并与蒸馏水的拉曼光谱线进行比较和分析.结果表明,水中所含杂质的浓度越高其对应拉曼谱线弯曲振动的强度就越大,弯曲振动与伸缩振动的强度比也越大,而且拉曼光谱线峰下的面积也随着杂质浓度的增大而增加.     

NOE Effect of Sodium Dodecyl Sulfate in Monomeric and Micellar Systems by NMR Spectroscopy

This paper describes the particular nuclear Overhauser effect (NOE) of sodium dodecyl sulfate (SDS) in monomeric and micellar systems. Two-dimensional NOE spectroscopy nuclear magnetic resonance (NMR) spectra of SDS in solution with concentration lower and higher than critical micellar concentration were recorded. In the first case diagonal and cross-peaks have different signs, and the opposite one was in the second case. This paper discusses theoretical background of this effect and we supposed that particular NOE can be used for inspection of SDS micelle formation during NMR researches. As a rough estimate of micelles formation an approach based on the difference between the chemical shifts in the monomer and micellar form of SDS was used.     

自发射荧光猝灭测定Gemini阴离子表面活性剂胶团聚集数

Gemini表面活性剂C11pPHCNa分子联接链上的对苯氧基在激发下自发射荧光。当浓度超过0.45 mmol·L-1时,激发光谱谱带的拓扑结构发生一系列变化,导致不同于对应的吸收光谱。由于联接链上的对苯氧基明显猝灭了外加探针芘发射的荧光,所以不能用传统的方法测定这类胶团的聚集数。文章利用甲基紫精(MV2+)可有效猝灭C11pPHCNa分子自发射荧光的原理,建立了测定这类胶团平均聚集数的方法。由该方法获得C11pPHCNa胶团平均聚集数为20.6;在溶液体相摩尔比为3∶7的C11pPHCNa/C₁₂-S₂-E₁-C₁₂·2Br体系中,混合胶团的平均聚集数为11.8。