罗丹明6G/MCM-41纳米复合物的发光蓝移

介孔分子筛MCM-41具有规则排列的纳米量级的孔道，可以作为宿主封装其他材料。利用这一性质，将激光染料罗丹明6G分子封装在介孔分子筛MCM-41中形成了纳米复合物。用透射电镜、小角度X射线衍射和荧光光谱等方法对纳米复合物的性质进行了分析。用波长为480nm的光对纳米复合物进行激发，得到的发光峰为531nm。与无限稀罗丹明6G乙醇溶液的发光峰相比，这一发光峰有15nm的蓝移和明显的宽化。我们认为当罗丹明6G分子封装在MCM-41的介孔中时，罗丹明6G分子与介孔分子筛孔道表面分子之间存在较强的相互作用(包括氢键、静电吸引等)，导致电子云被局域在具有较强吸引力的分子筛表面原子周围。引起激发态能量升高，发光峰蓝移。     

罗丹明6G在醇溶液中的荧光频移特性分析

罗丹明6G在甲醇、乙醇、乙二醇溶液中均发出较强的荧光。当醇溶液浓度为33.3%时,基本不存在频移现象。当醇溶液浓度为99.7%时,荧光峰发生蓝移或红移,分析认为该频移是由罗丹明6G和醇类物质分子相互作用(如氢键、静电吸引)导致激发态能量升高、荧光峰蓝移,与醇类物质分子中羟基OH的孤对电子跃迁导致荧光能量降低、荧光峰红移,这两种因素相互竞争的结果,且在高浓度醇溶液中,羟基OH数量越多,红移越明显。     

Investigation of Rhodamine 6G in oleic acid solution fluorescence under high pressure

Interesting behavior has been observed in the absorption spectra of the solution of Rhodamine 6G [C₂₈H₃₁N₂O₃Cl] in oleic acid [C₁₈H₃₄O₂] [K. Wieja et al., Pressure-induced changes in electronic absorption spectrum in oleic acid, High Press. Res. 30 (2010), pp. 130–134]. Application of high pressures to the solution has caused the reshaping of the absorption spectra curve, and the maximum of absorption has been shifted towards the longer wavelength. One of the most possible explanations of the changes in the absorption spectra is the formation of charge-transfer complexes in the solution. Pressure-induced changes of the VIS absorption spectrum in the mixture of Rhodamine 6G and oleic acid have been observed in comparison with the absorption spectrum of the mixture of Rhodamine 6G in ethanol. Moreover, changes have been observed in the fluorescence spectrum of the examined mixture, which indicated a fluorescent electronic band of a CT complex.     

A non-mixing technique for enhancement of the tuning range of Rhodamine 6G using Rhodamine B

An optical scheme for extension of spectral tuning range of Rhodamine 6G by Rhodamine B is reported. The dye solutions are kept separately in a specially designed coupled resonator. The tuning range of Rhodamine 6G dye laser is extended from 564–609 to 564–645 nm.     

掺杂Rhodamine 6G的平面波导型PMMA聚光器研制

通过聚光波导提高光的转换和收集效率,是提高太阳能电池效率、减少电池用量、降低光伏发电系统成本的重要途径。利用PMMA作为波导基质材料,Rhodamine 6G(罗丹明6G)作为荧光染料,通过涂覆方法,在表面积为50 mm×50 mm、厚度为5 mm的洁净PMMA衬底上制备出了荧光层厚度约为32 μm的平面波导型聚光器,并研究了荧光染料的掺杂浓度对其聚光比和光伏性能的影响。结果表明,当掺杂浓度为0.250%时,聚光器的聚光比和器件的光伏性能达到了最优,分别为0.45%和0.49%。     

胶束中的若丹明6G荧光增强和激光行为

使用阴离子表面活性剂十二烷基硫酸钠 (SDS)有效的增强了若丹明 6G染料水溶液的荧光 ,在若丹明 6G浓度分别为 5 47× 10 -7和 5 47× 10 -4 mol·L-1时 ,最大增强比率分别为 1 95和 9 7。在后一浓度下SDS的加入使若丹明 6G染料激光阈值降低 ,能量转化效率提高。不加SDS时的激光阈值功率密度约为 6 5MW·cm-2 ,加入 4 1× 10 -2 mol·L-1的SDS后 ,激光阈值功率密度降为 0 8MW·cm-2 。泵浦光功率密度为 6 5MW·cm-2 时 ,能量转化效率达到 2 5 %。同时还观察到SDS的加入使溶液吸收谱、荧光谱和染料激光发生了红移。对以上现象的物理机制进行了讨论。     

Development of temporal spectroscopic properties for Xerogel matrices doped with Rhodamine 6G dye

The solid host of a laser dye modifies its spectroscopic properties with respect to its liquid host. During the Sol-Gel process the dye molecules suffer from changing their environment. Two parameters affect this matter, the change in the concentration due to the evaporation of the solvent (drying) and the caging of dye molecules inside the pores or attachment to the silica network. Rhodamine 6G absorption and fluorescence spectra with different concentrations, during Sol-Gel time processing, have been studied. Both, absorption and fluorescence spectra of the dye in the solid host, for different concentrations, show a blue-shift relative to its liquid phase.     

氧化石墨烯如何猝灭罗丹明6G的荧光

考察了水相溶液中氧化石墨烯对罗丹明6G的高效荧光猝灭．借助稳态及时间分辨荧光光谱测量,结合对该二元体系线性吸收谱变化的细致分析,澄清了相关荧光猝灭机理,即动态猝灭与静态猝灭的联合猝灭机制．提出在静态猝灭过程中罗丹明6G与氧化石墨烯所形成的可能的基态复合物,并进一步讨论了二者之间的光致电子转移过程．     

R6G染料荧光对CS_2受激拉曼散射的高效放大(英文)

本文报道荧光介质(R6G乙醇溶液)对CS2受激拉曼散射Stokes波的高效放大,在共线配置下CS2的一阶、二阶Stokes波分别获得了1.7和96.6的增益。对荧光介质放大Stokes波机制进行了分析讨论。     

Study of absorption spectrum and dynamics evaluation of the indocyanine‐green first singlet excited state

Excited state absorption and excited state dynamics of indocyanine‐green (ICG) dissolved in dymethyl sulfoxide were measured using white‐light continuum Z‐scan (WLCZScan) and white‐light continuum pump–probe (WLCPP) techniques. The excited state absorption spectrum, obtained through Z‐scan measurements, revealed saturable absorption (SA) for wavelengths longer than 630 nm, while reverse saturable absorption (RSA) appeared, as indicated by a band at approximately 570 nm. Both processes were modeled by a three‐energy‐level diagram, from which the excited state cross‐section values were determined. SA and RSA were also observed in pump–probe experiments, with a recovery time in the hundreds of picoseconds time scale due to the long lifetime of the first excited state of ICG. Such results contribute to the understanding of ICG optical properties, allowing application in photonics and medicine. Copyright © 2010 John Wiley & Sons, Ltd.     

有机染料HEASPS在不同波长时的激发态吸收和双光子吸收性质研究

提出了有机染料反式 4 [4′ (N 羟乙基 N 乙基胺基 )苯乙烯基 ] N 甲基吡啶对甲苯磺酸盐 (简称HEASPS)非线性吸收的三态模型。认为在较短波长 (<1 0 0 0nm)时 ,双光子吸收和激发态吸收同时存在。成功地解释了该染料双光子吸收峰相对线性吸收峰的两倍的明显蓝移 ,以及最高上转换效率波长相对最强吸收波长的明显红移。提出了一种新的计算方法 ,利用不同波长的非线性透过率和不同波长的上转换效率 ,求出了该染料的双光子吸收截面和激发态吸收系数。     

罗丹明6G.四溴荧光素双显色体系浮选光度法测定锗的研究

向锗与茜素氨羧络合剂罗丹明６Ｇ形成的Ｇｅ（ＡＷＬＣ３（Ｒ６Ｇ）５甲苯浮选物，加入０．１ｍｏｌ／Ｌ的ＮａＯＨ的溶液，使Ｒ６ＧＹ颜色相同的四溴荧光互，形成等色染料离子对Ｒ６Ｇ＾＋；ＴＢＦ＾－再被甲苯浮选。将浮先物溶于丙酮，于５３０处进行光度测定，由于１０个染料分子同时吸光，使本方法具有很高的灵敏度：ε＝５．８×１０＾５Ｌ．ｍｏｉｌ＾－１，ｃｍ＾－１，锗含量在０．００４０－０．１ｍｇ／Ｌ服从比耳定律。     

Time-resolved studies on the photoisomerization of a phenylene-silylene-vinylene type compound in its first singlet excited state

In femtosecond laser-flash photolysis experiments, the first singlet excited state of trans-ST, ((E,E)-{1,4-bis(2-dimethylphenylsilyl)ethenyl}benzene) showed a strong S1(π,π^?)-Sn absorption band at 540 nm in acetonitrile and at 550 nm in hexane. The lifetime of this state was determined to be 13.2±2.0 and 11.1±1.5 ps, respectively. Intersystem crossing was shown not to be a principal route for the deactivation of this S1 state of trans-ST. Evidence for this conclusion involved two complementary nanosecond laser-flash photolysis experiments. In one experiment involving direct excitation, no transient absorption spectrum was detected in the 350-650 nm spectral range. Yet, in the second experiment, on triplet sensitization, using xanthone, a transient absorption at 400 nm was tentatively assigned to the triplet state absorption of trans-ST. Photoisomerization was monitored in nanosecond time-resolved bleaching experiments. From these experiments the trans-cis photoisomerization quantum yield was determined to be 0.23 on direct trans-ST excitation. In a xanthone-sensitized stationary-state excitation experiment, the trans-cis isomerization quantum yield was determined to be 0.32. The main deactivation route of trans-ST in its S1 state is repopulation of the ground state directly through internal conversion or with the intermediacy of conformers with twisted geometry.     

Fluorescence quantum yield of rhodamine 6G using pulsed photoacoustic technique

Experimental method for measuring photoacoustic(PA) signals generated by a pulsed laser beam in liquids is described. The pulsed PA technique is found to be a convenient and accurate method for determination of quantum yield in fluorescent dye solutions. Concentration dependence of quantum yield of rhodamine 6G in water is studied using the above method. The results indicate that the quantum yield decreases with increase in concentration in the quenching region in agreement with the existing reports based on radiometric measurements.     

The theory and experiment of solute migration caused by excited state absorptions

Nonsymmetrical transition from reverse-saturable absorption (RSA) to saturable absorption (SA) caused by excited state absorption induced mass transport of the CuPcTs dissolved in dimethyl sulfoxide is observed in an open aperture Z-scan experiment with a 21-ps laser pulse. The nonsymmetrical transition from RSA to SA is ascribed neither to saturation of excited state absorption nor to thermal induced mass transport, the so-called Soret effect. In our consideration, strong nonlinear absorption causes the rapid accumulation of the non-uniform kinetic energy of the solute molecules. The non-uniform kinetic field in turn causes the migration of the solute molecules. Additionally, an energy-gradient-induced mass transport theory is presented to interpret the experimental results, and the theoretical calculations are also taken to fit our experimental results.     

罗丹明6G缔合微粒共振散射光谱法测定过氧化氢

在0.020mol.L-1HCl-4.0×10-4mol.L-1KI-1.6×10-5mol.L-1Mo(Ⅵ)介质中,罗丹明6G(RhG)在540nm处有1个荧光峰,在540nm处有1个同步荧光峰。当有H2O2存在时,H2O2与过量的I-反应生成I3-,I3-与RhG形成缔合微粒,在320,400,595nm处产生3个共振散射(RS)峰;而在540nm处荧光峰猝灭。H2O2浓度在0.068~34μg.mL-1范围内与400nm波长处的共振散射光强度呈线性关系。据此建立了一个测定水中H2O2的共振散射光谱分析法。光谱研究结果表明,(RhG-I3)n缔合微粒和界面的形成是导致体系RS增强和荧光猝灭的根本原因。     

Spectroscopic and Laser Studies of Mixed Rhodamine 6G and 10-Phenyl-9-acetoxyanthracene Solutions

The spectroscopic and laser parameters of a mixed donor (10-phenyl-9-acetoxyanthracene derivations)-acceptor (rhodamine 6G) solutions have been determined. The studies performed show that rhodamine 6G is responsible for the lasting of the mixed solution. The 10-phenyl-9-acetoxyanthracene added to the R6G lasing solution decreases the spectral range of lasing and the gain value, G(), of the solution. These changes in the lasing parameters are caused by electron energy transfer processes of different types. The results of fluorescence studies of the mixed donor-acceptor solutions point out that the long-range dipole-dipole interaction mechanism of the static quenching accompanied by the formation of nonemitting complexes in the dye mixture is responsible for the noted lasing and fluorescence changes.     

氧化石墨烯猝灭罗丹明6G荧光的机理研究

The fluorescence quenching of Rhodamine 6G (R6G) by graphene oxide (GO) was interrogated by R6G fluorescence measurements using a set of controlled GO samples with varied C/O ratios as the quencher.The carbonyl groups on the GO nanosheet turned to play a dominant role in quenching the R6G fluorescence.The quenching in the static regime can be described by the "sphere of action" model.The significant absorption of the R6G fluorescence by the ground-state complex formed between R6G and GO was identified to be responsible for the static quenching.This work offers helpful insights into the fluorescence quenching mechanisms in the R6G/GO system.     

用非简并泵浦探测方法研究C70/甲苯溶液的激发态吸收动力学

通过非简并的时间分辨泵浦探测技术对C70富勒烯/甲苯溶液的非线性光学性质进行了研究。在532 nm波长的皮秒激光脉冲泵浦下,用600 nm的皮秒激光脉冲测量了C70富勒烯的激发态非线性吸收动力学响应。利用五能级模型对实验结果进行了数值模拟,得到了非简并情况下C70富勒烯分子的光物理参数。实验结果表明:C70富勒烯在简并和非简并情况下的激发态寿命没有变化,但非简并情况下的单重态吸收截面要比简并情况下单重态吸收截面小。     

Determination of the rate constant of oxygen quenching of the excited states of molecules from the singlet oxygen luminescence

We have pioneered a method of determining the rate constant of quenching of the excited electronic states of molecules by molecular oxygen from measurements of the kinetics of photosensitized luminescence of singlet molecular oxygen (^lδ_g). The method can be used in the case where the lifetime of the excited electronic state in an air-saturated solution is comparable with or larger than the luminescence time of the singlet molecular oxygen in the given solvent. It is shown that this situation is implemented on quenching, by molecular oxygen, of the excited triplet states associated with the biopolymers of tetrapyrrole molecules in aqueous (H₂O and D₂O) solutions. Translated from Zhurnal Prikladnoi Spektroskopii, Vol. 67, No. 3, pp. 401–404, May–June, 2000.