光生酸剂光分解行为的研究

论文以对酸敏感的罗丹明B为示踪剂，通过采用分光光度法和荧光光谱法，建立了光生酸剂在溶剂中和在高分子薄膜中光分解行为的评价方法。研究结果表明，本研究提出的光生酸剂在溶液中和在高分子薄膜中产酸效率的评价方法切实可行，能够准确地定量评价光生酸剂的光化学反应和产酸行为，用这种测量方法可以评价现有的三嗪类与硫翁盐类光生酸剂的产酸优劣。     

高效光生酸剂的设计合成与性能研究

成功合成了一类新型硫铭盐光生酸剂，其结构经^1HNMR、IR分析确证，同时对其物理性质进行了基本考察。利用研究室确定的测定产酸效率的方法对新型硫铺盐和三嗪类光生酸剂的产酸性能进行了基本评价。通过比较实验结果得到，PAGC25′和PAGC17在405nm光源照射下，具有良好的产酸性能，从而筛选出比较高效的光生酸剂。     

新型锍鎓盐类光生酸剂的产酸性能研究

对合成的两种新型锍鎓盐光生酸剂进行了基本物性考察，表明它们有较高的热分解温度和在常用有机溶剂中有较好的溶解性，并考察了其在405、365nm下乙腈中的分解及产酸性能。根据本实验室研究的方法计算出分解量子产率和产酸效率。     

几种硫鎓盐类光产酸剂的合成与性质

硫鎓盐类光产酸剂因其较高的产酸效率和好的热稳定性而广泛应用于化学增幅光致抗蚀剂中。本论文选择不同的酚化合物为原料,使之与二甲基亚砜和氯化氢反应,合成了一系列硫鎓盐化合物,研究了其在有机溶剂中的溶解性、热稳定性、紫外吸收性质及其光解特性。以低压汞灯为曝光光源,测定了该类光产酸剂的光解量子效率在0.2—0.7范围。     

光产酸源的新进展

本人已对UV产酸物质、UV产酸过程及UV固化作过综述。在UV产酸固化过程中,光产酸物质(光产酸源)事实上是作为一种酸引发剂,去引发一些物质发生开环聚合、加成聚合或交联反应的。它是一个由小分子变为大分子或由线型高分子变为体型硕大分子的过程。其用途是作光硬化涂料和负     

酸修饰氮化碳的制备及其可见光催化性能研究

采用水热法以酸修饰石墨相氮化碳，考察酸种类、酸用量、及水热温度对g-C₃N₄结构及光催化性能的影响，并以罗丹明B水溶液模拟废水，于可见光下对催化剂活性进行评价分析。利用X射线衍射(XRD)、傅里叶红外光谱仪(FT-IR)、紫外-可见-近红外分光光度计(UV-Vis)、物理吸附仪(N₂-physisorption)、荧光光谱(PL)等多种表征方法进行测试。结果表明：酸修饰对氮化碳起到了氧化作用，影响了g-C₃N₄的能带结构，带隙能增加，光吸收边有蓝移现象。且酸处理刻蚀了体相g-C₃N₄,有效地增大了其比表面积，增强其暗吸附能力，并提高电子-空穴对的分离效率。优化制备条件，发现当采用浓硝酸修饰、酸用量为0.3mL、水热温度为180℃时，所得催化剂在可将光下催化效果最佳，其降解速率是体相g-C₃N₄的4.33倍。     

功能化聚苯乙烯共聚荧光微球的制备与表征

以烯丙基罗丹明B为荧光染料,采用分散聚合法制备了粒径均一的聚苯乙烯共聚荧光微球,并通过磺化反应,在荧光微球表面引入功能基——磺酸基。环境扫描电子显微镜和荧光显微镜观察表明,产物微球具有良好的单分散性,荧光性能好且稳定;电导率测定表明,微球表面磺酸基的含量较高,约为90μmol/g;荧光和紫外-可见分光光度计表明,聚合在聚苯乙烯共聚荧光微球中的烯丙基罗丹明B具有和烯丙基罗丹明B一致的性质,并证实磺酸基聚苯乙烯共聚荧光微球和烯丙基罗丹明B在乙醇中具有不同的荧光光谱。     

功能化聚苯乙烯共聚荧光微球的制备与表征EI北大核心CSCD

以烯丙基罗丹明B为荧光染料,采用分散聚合法制备了粒径均一的聚苯乙烯共聚荧光微球,并通过磺化反应,在荧光微球表面引入功能基——磺酸基。环境扫描电子显微镜和荧光显微镜观察表明,产物微球具有良好的单分散性,荧光性能好且稳定;电导率测定表明,微球表面磺酸基的含量较高,约为90μmol/g;荧光和紫外-可见分光光度计表明,聚合在聚苯乙烯共聚荧光微球中的烯丙基罗丹明B具有和烯丙基罗丹明B一致的性质,并证实磺酸基聚苯乙烯共聚荧光微球和烯丙基罗丹明B在乙醇中具有不同的荧光光谱。     

罗丹明B染料掺杂介孔二氧化硅的研究进展

介孔二氧化硅掺杂染料后在传感器、荧光探针、药物输送、以及非线性光学材料特别是激光材料耐光性等领域具有广阔的应用前景并已成为当前研究的热点。本文综述了近十年来以介孔二氧化硅为主体掺杂荧光染料罗丹明B的研究进展,详细讨论了染料在介孔二氧化硅中的形成机理、聚集状态以及影响规律。最后,对罗丹明B染料掺杂介孔二氧化硅的研究进行了展望。     

溶胶-凝胶法制备铁酸铋纳米颗粒及催化性能研究

采用溶胶-凝胶法制备了BiFeO_3粉体,通过XRD和SEM对BiFeO_3粉体进行表征,探索了煅烧温度和煅烧时间对铁酸铋粉体结构和形貌的影响规律,制得高质量的纯相样品。研究了BiFeO_3对罗丹明B的光催化降解行为,结果表明,随着溶液pH降低,BiFeO_3光催化效率明显提高。此外,还分析了光降解机理,考察了BiFeO_3粉体在H_2O2协同作用下对罗丹明B的催化降解效应,结果证实这主要是一种芬顿效应引起的。     

罗丹明B的荧光猝灭法测定钢铁中微量钨

本文研究了在酸介质中,NaCl存在的条件下,罗丹明B与钨酸根WO_4~_(2-)络合生成三元络合物使罗丹明B试剂荧光猝灭。以365 nm为最大激发波长,测定594 nm最大发射荧光强度。用钠型Dowex50W—X4离子交换树脂胶柱交换分离溶液中共存的磷酸根、重铬酸根、Cr~(3+)、Fe~(3+)等干扰离子,利用罗丹明B荧光强度减弱的程度和钨含量呈线性关系,测定钢样中微量钨。     

Preparation,characterization, and morphology of on/off detection indicator based on rhodamine 6G-adamantanamine loaded onto nonwoven polyethylene terephthalate

Traditionally, food quality is evaluated by consumers through comparison of the production and expiration dates of the product. However, product shelf life cannot be the real and only parameter of food quality, especially within a variety of storage environments. Therefore, new indicators of food quality are needed to provide food safety to the consumer. In this work, we reported a detection indicator based on rhodamine 6G-adamantanamine and β-cyclodextrin (β-CD) polyelectrolyte cross-linked onto a nonwoven polyethylene terephthalate textile support, which can be used as the indication of food quality by means of the irreversible change of fluorescence. The relationship between the increase of fluorescence and pH variation was also reported. Considering food safety, a migration experiment was carried out using a food simulation system. When pH changed to 6.8, the evident fluorescence can be observed by naked eye at 650-nm excitation wavelength. β-CD can not only act as a good carrier of rhodamine 6G-adamantanamine but also enhanced the fluorescence to indicate whether rhodamine 6G-adamantanamine was loaded onto β-CD polyelectrolyte or nonwoven polyethylene terephthalate. After 250 h of migration experiment at 25°C, it was found that the fluorescent substances slightly migrated, and the migration under acidic conditions was almost negligible. The fluorescence enhancement performance and migratory behavior indicated that the material had the potential as a fluorescent intelligent indicator for food packaging.     

羧基功能化聚苯乙烯荧光微球的制备及表征

以苯乙烯、丙烯酸为单体,引入疏水性荧光染料罗丹明6G(Rh6G),采用微乳聚合法制备羧基聚苯乙烯荧光微球,并分析了表面活性剂、引发剂、丙烯酸用量对产物粒径分布的影响,考察了羧基聚苯乙烯荧光微球的浓度对荧光强度的影响。通过粒度分析仪、扫描电子显微镜、红外光谱仪、紫外吸收光谱以及荧光光谱仪对样品的纳米特性、形貌、结构和荧光性能进行了表征。结果表明,用微乳聚合法制备出50~250nm的羧基聚苯乙烯荧光微球,粒径均一且呈单分散性。紫外光谱图测试表明,在533nm左右有吸收峰。荧光光谱测试表明,羧基功能化的荧光聚苯乙烯微球浓度≤0.01%,其荧光最大激发峰为527nm,最大发射峰在555nm处;浓度高于0.01%时,荧光光谱出现红移,且荧光强度减弱。     

Counting single chromophore molecules for ultrasensitive analysis and separations on microchip devices

Separations of 15 pM rhodamine 6G and 30 pM rhodamine B performed in a micromachined electrophoresis channel were detected by counting fluorescence bursts from individual molecules. The migration times, peak widths, and analyte concentrations were estimated from the number and the migration time distribution of the detected molecules. Concentration detection limits estimated at >99% confidence were 1.7 pM rhodamine 6G and 8.5 pM rhodamine B. The separations required <35 s and the relative migration time uncertainties were less than 2.0%. These are the lowest detection limits reported for microchip separation devices and the first example of single-chromophore molecular counting for detection of chemical separations.     

Energy Transfer in Dye Mixtures Studied by Laser Fluorimetry

Radiationless energy transfer in the laser dye mixture consisting of rhodamine 6G (donor) and rhodamine B (acceptor) has been studied using fluorescence lifetime measurements. The main aim was to observe directly the effect of energy transfer on the excited-state lifetime of the donor. Estimates of the energy transfer parameters are in agreement with predictions of the Forster theory for resonance transfer based on long-range dipole-dipole interactions.     

The fluorescence behavior from SAM of dendron with rhodamine B as a center

We studied energy transfer between rhodamine B molecules centered in each corn-shaped dendrons that forms self-assembled monolayer (SAM) film on an Au substrate. A SAM film using dendron moiety as a spacer can change the distance between rhodamines depending on the size, so that the energy transfer from an initially photo-excited rhodamine to its surrounding molecules can be controlled. The absorption spectrum of a SAM film for each generation of dendron was measured to ascertain a linear correlation between the generation and the distance. Picosecond time-resolved fluorescence spectra showed clear differences in the fluorescence decay dynamics between third-generation (G3) and fourth-generation (G4) dendron SAM films. In addition, we found that “dry” or “wet” dendron SAM considerably influenced fluorescence behavior. As a result, the use of “wet” G4 SAM is suitable in preserving photo-excitation energy. This is because it gave almost equal dynamics to G4 dendron in the dilute solution and prevented deactivation by energy dissipation.     

Surface-enhanced spectra on D-gluconic acid coated silver nanoparticles

Coated silver (Ag) colloids synthesized with D-glucose permit the observation of surface-enhanced fluorescence (SEF) and surface-enhanced resonance Raman scattering (SERRS) of the rhodamine B (RhB) molecule. The organic coating formed during the synthesis of the Ag nanostructures was identified by its surface-enhanced Raman scattering (SERS) spectrum as D-gluconic acid. The RhB molecule is used to exemplify the distance dependence of SEF and SERRS on the coated Ag nanostructures. The fluorescence enhancement factor for RhB on D-gluconic acid coated silver nanoparticles was determined experimentally and estimated using a simple model. Further support for the plasmon enhancement is obtained from the fact that the measured fluorescence lifetime of RhB on the silver coated with D-gluconic acid is shorter than that found on a glass surface. A very modest enhancement factor is obtained, as expected for very short distance between RhB and the metal surface. Given the very thin metal-fluorophore separation, estimated from the size of the D-gluconic acid, the energy transfer or fluorescence quenching is still efficient and the SEF enhancement is just overcoming the energy transfer. Therefore, both SEF and SERRS are observed. Notably, the aggregation of coated nanoparticles also increases the enhancement factor for SEF.     

含罗丹明B的纳米复合介孔薄膜的制备和性能(英文)

采用溶胶-凝胶技术、蒸发诱导自组装法,通过酸/酸二步法控制实验条件,实验中采用表面活性剂十六烷基三甲基溴化氨(CTAB)为模板剂,正硅酸乙酯为硅源、罗丹明B、以及二次去离子水,盐酸为催化剂等原料制备前驱体溶胶.通过简单提拉迅速蒸发溶剂制备介孔薄膜,对介孔薄膜进行了X射线衍射、透射电子显微镜表征,观察了薄膜样品的吸收光谱和荧光光谱.含罗丹明B膜的吸收光谱表明主峰是RhB单体的吸收和微弱吸收的次峰是RhB形成的二聚体的吸收.而在荧光光谱中只有一个发射谱带,这是RhB单体的最低激发能级到基态级的跃迁,含罗丹明B的纳米复合介孔薄膜中,随着RhB浓度的增大,荧光峰位发生红移,这可以说明激发态分子的偶极矩减小.     

Template-Free Synthesis of Phosphorus-Doped g-C3N4 Micro-Tubes with Hierarchical Core–Shell Structure for High-Efficient Visible Light Responsive Catalysis

This work reports a new form of tubular g-C₃N₄ that is featured with a hierarchical core–shell structure introduced with phosphorous elements and nitrogen vacancies. The core is self-arranged with randomly stacked g-C₃N₄ ultra-thin nanosheets along the axial direction. This unique structure significantly benefits electron/hole separation and visible-light harvesting. A superior performance for the photodegradation of rhodamine B and tetracycline hydrochloride is demonstrated under low intensity visible light. This photocatalyst also exhibits an excellent hydrogen evolution rate (3631 µmol h⁻¹g⁻¹) under visible light. Realizing this structure just requires the introduction of phytic acid into the solution of melamine and urea during hydrothermal treatment. In this complex system, phytic acid plays as the electron donor to stabilize melamine/cyanuric acid precursor via coordination interaction. Calcination at 550 °C directly renders the transformation of precursor into such hierarchical structure. This process is facile and shows the strong potential toward mass production for real applications.     

Nanochannels on a fused-silica microchip and liquid properties investigation by time-resolved fluorescence measurements

We have fabricated nanometer-sized channels, demonstrated a technique for the introduction of liquid into the channels, and carried out time-resolved fluorescence measurements of aqueous solutions. In this study, 330-nm- and 850-nm-sized channels were fabricated on fused-silica substrates by fast atom beam etching and hydrofluoric acid bonding methods. A liquid introduction method utilizing capillary action was demonstrated. The liquid introduction was observed under an optical microscope, and the liquid velocity during the introduction was analyzed by surface energy and macroscale hydrodynamics. The liquid velocity due to capillary action in the nanometer-sized channel seemed more than four times slower than the estimation. Then, aqueous solutions of rhodamine 6G (R6G), sulforhodamine 101 (SR101), and rhodamine B (RB) in the channels were measured by time-resolved fluorescence spectroscopy; spectra of the same solution in a 250-microm-sized channel were also measured as a reference for the macrospace. Although the fluorescence spectra in the 330-nm-, 850-nm- and 250-microm-sized channels agreed with one another, the fluorescent decays in the nanometer-sized channels were faster for R6G and SR101 and slower for RB than the respective decays in the 250-microm-sized channels. The results suggested the solutions had lower dielectric constants and higher viscosities in the nanometer-sized channels.