含三苯胺单元的共轭聚合物的合成、表征及应用

采用 Wittig 方法制得了未封端及封端的线性聚三苯胺-对苯乙烯撑型聚合物(分别简称为:TPA-DOPPV1,TPA-DOPPV2),并对共轭聚合物进行了表征和性能测试.封端后的聚合物溶液和固体膜在紫外光照射下均发出较强的绿光.对这类聚合物在硝基化合物检测方面的应用进行了初步研究,结果表明:封端后的共轭聚合物在邻硝基甲苯(o-NT)荧光检测上的性能明显提高,当o-NT 浓度为 21.5×10-3 mol/L 时,荧光猝灭效果达到了 96%;在2,4-二硝基甲苯(DNT)、对硝基甲苯(P-NT)和对苯醌(p-BQ)蒸汽中放置 10 s 时,其薄膜的荧光猝灭效率分别达到 30%、15.6%和 3.1%.TPA-DOPPV2 的合成操作较为简便,具有一定的检测灵敏性,是一种潜在的硝基类爆炸物荧光检测材料.     

水分散超支化共轭聚合物纳米粒子的制备及其对苦味酸的高灵敏荧光检测

采用Suzuki细乳液聚合以及后功能化反应,制备了季铵盐末端的水分散超支化共轭聚合物纳米粒子(HCPN-QA),用于高灵敏度和高选择性的检测2,4,6-三硝基苯酚(PA).带正电荷的季铵盐端基以及疏水的超支化共轭聚合物核心,使HCPN-QA对水中呈酸性的PA产生静电吸引与疏水富集的协同作用,产生高度灵敏的荧光猝灭响应,检测限达到0.18μg/L,猝灭常数达到6.36×10~7 L/mol,相比于有机相分散的超支化共轭聚合物纳米粒子HCPN-OMe,HCPN-QA检测限低了4个数量级,猝灭常数高出3个数量级.通过研究HCPN-QA粒径对PA检测灵敏度的影响,发现纳米粒子粒径对PA的检测灵敏度影响很小.并且,HCPN-QA对PA的猝灭响应显著高于TNT及其他硝基爆炸物,表现出很好的选择性以及竞争选择性.此外,HCPN-QA检测试纸对PA固体颗粒的检测表现出很高的灵敏度,检测限达到66 pg/mm~2.     

基于桥联柱[5]芳烃的刺激响应性荧光超分子聚合物用于硝基化合物的传感检测

本文利用二硫键桥联的双柱[5]芳烃和烷基溴修饰的四苯基乙烯之间的主客体作用制备了一种荧光超分子聚合物.在谷胱甘肽的存在下,柱芳烃桥链上二硫键的断裂使得该荧光超分子聚合物被破坏,体系荧光猝灭.值得注意的是,该荧光超分子聚合物能够有效地检测硝基化合物,最低检测限可达10-8 mol·L-1,表明其在硝基化合物检测方面具有良...     

新型聚苯撑乙烯类阳离子共轭聚合物的合成及其荧光猝灭行为

通过Wittig反应合成了新型聚对苯乙烯撑类阳离子共轭聚合物, 并进行了相关结构表征和光学性质表征. 从1H NMR 谱图分析得知, 该聚合物具有一定含量的顺式构型. 经过季铵化以后得到相应的阳离子共轭聚合物. 荧光猝灭行为研究表明, 该阳离子共轭聚合物表现出不完全荧光猝灭.     

阳离子荧光共轭聚合物结合纳米颗粒用于DNA检测

利用纳米颗粒对目标DNA的富集、分离作用以及阳离子荧光共轭聚合物良好的荧光特性,建立了一种特异性检测DNA的新方法.首先将标记有猝灭基团的DNA捕获探针修饰到纳米颗粒上,捕获互补的DNA分子;然后加入S1核酸酶,除去未捕获到互补DNA的捕获探针;最后用Dnase Ⅰ将颗粒上的双链切断,使猝灭基团从纳米颗粒上解离下来,与阳离子荧光共轭聚合物结合并猝灭其荧光.结果表明,目标核酸的浓度与该聚合物的荧光猝灭程度正相关,且具有良好的特异性,线性响应范围为5.0～40 nmol/L; 检出限为3.7 nmol/L(S/N=3).     

含芴共轭单元的超支化聚合物的合成及表征

以芴和季戊四醇为初始物,分别合成了具有芴共轭单元和季戊四醇多臂结构的两种聚合单体,进一步采用Suzuki反应合成出一种结构新颖的部分共轭结构的超支化聚合物.利用紫外吸收光谱和荧光发射光谱对聚合物予以表征,结果表明,超支化聚合物具有与模型化合物分子相似的发光行为,既可以发出纯正的蓝光,又表现出支化结构对荧光发射的影响.差...     

纤维素接枝改性芴-苯和咔唑-苯共聚物及其对硝基芳烃的检测

采用Suzuki偶联反应将合成的芴-苯和咔唑-苯共聚物接枝到经化学改性的纸纤维素上,制备了可用于硝基芳烃检测的传感纸纤维素.荧光猝灭研究显示,由于两种传感纸纤维素具有的大比表面积和孔道结构有利于2,4-二硝基甲苯(DNT)蒸气分子的快速扩散,因此二者比薄膜态具有更高的荧光猝灭效率.荧光猝灭的可逆性研究显示,两种传感纤维素经过四次猝灭-恢复循环后,对DNT气态分子依然具有较高的猝灭效率,表明制备的纸纤维素具有良好的荧光猝灭可逆性和稳定性.     

以吖啶染料荧光猝灭为基础的卤素阴离子检测研究

合成了两种吖啶及吖啶橙盐类小分子化合物和带有吖啶盐的三元共聚物.研究了它们在溶液中的荧光被卤素离子猝灭的问题.发现它们能强烈地被碘离子所猝灭而不易被氯离子猝灭,表明这类化合物有可能用于在有氯离子存在条件下对碘、溴离子的检测.对荧光猝灭机理进行的研究发现,卤素离子的猝灭能力并不和它们对发光化合物的系间窜越和三重态的生成等有关,而是和阴离子对极化分子的作用减弱了分子内的电荷转移能力相关.     

超支化共轭聚合物的合成、性质及在光电器件中的应用研究进展

简述超支化共轭聚合物光电活性材料研究进展,设计、合成了多种具有3-D立体结构的超支化共轭聚合物,研究了它们的结构与性能的关系及其在器件上的应用.实验结果表明,这种聚合物具有良好的溶解性,可成膜性和高的发光效率.可应用于发光二极管(LED),发光电化学池(LEC),光伏打电池等器件.这类化合物不仅可以作为发光材料,还可以通过修饰得到具有分子或离子识别、信息存储性能的特殊功能材料.     

水溶性荧光共轭聚合物在检测出血热病毒中的应用

利用出血热病毒抗体-L133/抗原-EHF对水溶性荧光共轭聚合物聚(5-甲氧基-2-(3-磺酰化)丙氧基-1,4-对苯撑乙烯), (简写为MPS-PPV)荧光的增强/猝灭作用、抗原-EHF与抗体-L133之间的特异性相互作用及作用前后荧光强度的变化, 建立了一种基于水溶性荧光共轭聚合物荧光猝灭可逆的高灵敏、均相免疫测定新方法, 实现了出血热病毒抗 原-EHF的快速、灵敏检测, 检测抗原-EHF的线性范围是4.8×10^－9～5.0×10^－8 mol/L, 检出限为1.7×10^－9 mol/L. 实验表明, 生物分子对聚合物的荧光增强或猝灭不仅是静电作用, 而且还表现为聚合物形态构造的变化.     

Tuning the optical properties of hyperbranched polymers through the modification of the end groups

Dye‐capped, hyperbranched, conjugated polymers were prepared by the modification of the peripheral bromo end groups of the hyperbranched polymer core with a palladium‐catalyzed Suzuki–Miyaura cross‐coupling reaction. The dye‐modified, hyperbranched polymers had high molecular weights and displayed good solubility in common organic solvents such as tetrahydrofuran, toluene, and chloroform. The structure of the dye‐modified, hyperbranched polymers was characterized by ¹H and ¹³C NMR and elemental analysis. The thermal properties of five kinds of hyperbranched polymers were investigated with thermogravimetric analysis and differential scanning calorimetry. The optical properties of the dye‐capped, hyperbranched polymers were investigated with ultraviolet‐absorption and fluorescence spectroscopy. The hyperbranched structure could effectively reduce the aggregation of the peripheral dyes. The emission colors of the hyperbranched polymers could be easily tuned by end‐group modification. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 111–124, 2007     

Effects of hyperbranched and linear architecture on properties of polymers composed of poly(ɛ-caprolactone) and hydroxycinnamic acid

Photoreactive and degradable polymers with linear and hyperbranched architectures which composed of poly(?-caprolactone) and hydroxycinnamic acid or its substituted derivatives were synthesized by thermal melt-polycondensation. The chemical structures of the polymers were confirmed by FTIR and ¹H NMR measurements. The polymers showed good photoreactivities and fluorescent properties, and the hyperbranched polymers showed higher photoreactive speed and weaker fluorescence properties. These polymers had excellent thermal stabilities due to the rigid conjugated structures and the π-π strcking interaction of the cinnamoyl group, especially for the hyperbranched polymer. Moreover, the hydrolysis experiments and the XRD results revealed that the hyperbranched and linear polymers are amorphous and crystalline, respectively, and the degradation rate of amorphous polymers are faster than crystalline samples.     

Triazatruxene-containing hyperbranched polymers: Microwave-assisted synthesis and optoelectronic properties

Hyperbranched polymer structures represent a class of high-functionality building blocks with excellent three-dimensional topology for the construction of highly substituted conjugated polymers. In this contribution, an efficient microwave synthesis protocol toward the synthesis of conjugated hyperbranched polymers is presented. A novel series of soluble hyperbranched polyfluorenes (PTF1-PTF3) incorporating triazatruxene moiety as the branch units with various branching degrees have thus been successfully constructed with good yields and high molecular weight via a facile “A2+B2+C3” approach. The structures of the hyperbranched polymers were confirmed by NMR and GPC. Their thermal, optical, and electrochemical properties of the hyperbranched polymers were also investigated. The results showed that introduction of triazatruxene units into the hyperbranched structure endowed the polymer with good thermal stability and highly amorphous properties. Photophysical investigation of PTFx revealed strong blue emission in both solution and solid states. Hyperbranched polymers with higher degree of branching and proper content of linear fluorene units exhibited better photophysical properties in terms of narrow emission spectra and relatively high quantum efficiency as well as improved thermal spectral stability. The triazatruxene branching unit also played a role in raising the HOMO energy levels relative to those of polyfluorenes that would help to improve the charge injection and transport properties. The incorporation of triazatruxene unit into hyperbranched polymers has thus explored an effective avenue for constructing optoelectronic polymers with improved functional characteristics.     

Energy transfer mediated fluorescence from blended conjugated polymer nanoparticles

Nanoparticles consisting of a derivative of the blue-emitting conjugated polymer polyfluorene doped with green-, yellow-, and red-emitting conjugated polymers were prepared by a reprecipitation method. The nanoparticles can be described as a system of densely packed chromophores that exhibit efficient energy transfer from the host to the dopant polymers. Fluorescence quenching analysis of the host polymer as a function of the dopant concentration indicates that one energy acceptor molecule can effectively quench 90% of the fluorescence of a nanoparticle consisting of 100-200 host conjugated polymer molecules. A nanoparticle energy transfer model was developed that successfully describes the quenching behavior of a small number of highly efficient energy acceptors per nanoparticle. The fluorescence brightness of the blended polymer nanoparticles was determined to be much higher than that of inorganic quantum dots and dye-loaded silica particles of similar dimensions. The combination of high fluorescence brightness and tunable fluorescence of these blended nanoparticles is promising for ultrasensitive fluorescence-based assays.     

Synthesis of hyperbranched polymers with precise conjugation length

A set of AB₂ type monodisperse conjugated oligomers carrying two bromo functional groups and one boronic ester functional group were prepared by iterative deprotection and Sonogashira cross‐coupling reactions. Suzuki polycondensation of these AB₂ type monodisperse oligomers afforded hyperbranched polymers. The hyperbranched conjugated polymers we prepared possess not only precisely controlled conjugation length like monodisperse conjugated oligomers but also the structural feature of hyperbranched polymers. Optical property investigation demonstrated that the maximum absorption and emission wavelength red‐shifted along with the increasing of the conjugation length between the two branching points and the hyperbranched structure could effectively reduce the aggregation of the conjugated polymer chains. © 2006 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 1084–1092, 2007     

Specific thermoresponsive behaviours exhibited by optically active and inactive phenylalanine modified hyperbranched polyethylenimines in water

Optically active and inactive hyperbranched polymers with specific thermoresponsive behaviours in water were reported.Through two steps hyperbranched polyethylenimine (HPEI) polymers terminated with different amount of D-phenylalanine (D-Phe),L-phenylalanine (L-Phe) or DL-phenylalanine (DL-Phe) were prepared and characterized.The analyses on the solution properties by turbidimetry,dynamic light scattering,fluorescence probe and 1H-NMR demonstrated that all the polymers exhibited specific thermoresponsive behaviours in water,including:(1) In the dilute polymer concentration region,increasing the polymer concentration led to the increase of phase transition temperature;(2) The optically inactive thermoresponsive hyperbranched polymers showed a higher cloud-point temperature (Tcp) than their corresponding optically active ones in a relatively higher polymer concentration;(3) At the same polymer concentration the hydrophobic groups of the optically inactive HPEI-DL-Phe formed more perfect hydrophobic domain than those of the optically active HPEI-L-Phe and HPEI-D-Phe.     

Hydroxyl‐terminated hyperbranched aromatic poly(ether‐ester)s: Synthesis,characterization, end‐group modification,and optical properties

Novel AB₂‐type monomers such as 3,5‐bis(4‐methylolphenoxy)benzoic acid ( monomer 1 ), methyl 3,5‐bis(4‐methylolphenoxy) benzoate ( monomer 2 ), and 3,5‐bis(4‐methylolphenoxy)benzoyl chloride ( monomer 3 ) were synthesized. Solution polymerization and melt self‐polycondensation of these monomers yielded hydroxyl‐terminated hyperbranched aromatic poly(ether‐ester)s. The structure of these polymers was established using FTIR and ¹H NMR spectroscopy. The molecular weights (M_w) of the polymers were found to vary from 2.0 × 10³ to 1.49 × 10⁴ depending on the polymerization techniques and the experimental conditions used. Suitable model compounds that mimic exactly the dendritic, linear, and terminal units present in the hyperbranched polymer were synthesized for the calculation of degree of branching (DB) and the values ranged from 52 to 93%. The thermal stability of the polymers was evaluated by thermogravimetric analysis, which showed no virtual weight loss up to 200 °C. The inherent viscosities of the polymers in DMF ranged from 0.010 to 0.120 dL/g. End‐group modification of the hyperbranched polymer was carried out with phenyl isocyanate, 4‐(decyloxy)benzoic acid and methyl red dye. The end‐capping groups were found to change the thermal properties of the polymers such as T_g. The optical properties of hyperbranched polymer and the dye‐capped hyperbranched polymer were investigated using ultraviolet‐absorption and fluorescence spectroscopy. © 2008 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 46: 5414–5430, 2008     

pH and thermo responsive aliphatic tertiary amine chromophore hyperbranched poly(amino ether ester)s from oxa-Michael addition polymerization

In this research, we developed a novel and facile strategy to prepare aliphatic tertiary amine chromophore hyperbranched poly(amino ether ester)s with pH and thermo responsiveness via phosphazene base (t-BuP₂) catalyzed oxa-Michael addition polymerization of triethanolamine with ethylene glycol diacrylate at room temperature. UV–vis and fluorescence analyses results showed that the tertiary amine at branching point for hyperbranched poly(amino ether ester)s is very important to retain strong blue fluorescence of tertiary amine chromophore. Moreover, the hyperbranched poly(amino ether ester)s exhibit an aggregation caused quenching (ACQ) fluorescence, solvent induced red-shifted emission, molecular weight, and temperature dependent emission characters. More interestingly, the hyperbranched poly(amino ether ester)s show extreme acid induced quenching fluorescence phenomenon, and also display good water solubility, specific recognition of Fe³⁺ ion, low cytotoxicity, and bright cell imaging, which could serve as a microenvironment-responding fluorescent probe for application in chemical sensing, cell imaging, drug delivery, or disease diagnostics. This research provides a versatile method for the preparation of stimuli-responsive aliphatic tertiary amine chromophore polymers, and supplies ideas for researchers to explore other unconventional fluorescent polymers for application.     

Synthesis,two‐photon absorption,and optical power limiting of new linear and hyperbranched conjugated polyynes based on bithiazole and triphenylamine

Two new linear and hyperbranched conjugated polymers P1 and P2 have been synthesized by Sonogashira coupling reaction, in which the main chain consists of bithiazole moieties as electron acceptors and triphenylamino groups as donors. The conjugated polymers were characterized by TGA, UV–vis absorption, fluorescence emission, electrochemical cyclic voltammetry, and two‐photon absorption measurements. They exhibited excellent solubility in organic solvents and high thermal stability (5% of weight loss at 299 °C). The two‐photon absorption cross sections (σ) measured by the open aperture Z‐scan technique using 140 femtosecond (fs) pulse were determined to be 1014 and 552 GM per repeating unit for P1 and P2 , respectively. This result shows that the σ of linear conjugated P1 is higher than that of hyperbranched P2 , indicating that the linear polymer offers better intramolecular charge transfer ability. In THF, P1 and P2 exhibit intense frequency up‐converted fluorescence under the excitation of 140 fs pulses at 800 nm with the peaks located at 580 and 548 nm, respectively. Meanwhile, the optical limiting behaviors for the polymers were studied by using a focused 800 nm laser beam of 140 fs duration. It was found that these polymers also exhibit good optical‐limiting properties and make them potential candidates for optical limiters in the photonic fields. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011     

Rotaxanated conjugated sensory polymers

Two highly emissive conjugated polymers with tethered rotaxane repeat units are reported. Hydrogen bonding between acidic alcohols and the N-heteroaromatic groups in the rotaxanes attenuates polymer fluorescence. In addition, the rotaxane groups create precise three-dimensional pockets for metal binding, which results in fluorescence quenching. Exposing thin films of Zn-doped polymers to alcohol vapors reverses the quenching by up to 25%.