Uniform composition film of hydrophilic colloidal gold nanoparticles and hydrophobic carbazole functionalized fluorene trimers for enhanced fluorescence and stability

Compositing gold nanoparticles into conjugated molecules have been developed to be one of the most important approaches to increase stability, since degradation of conjugated materials is now one of the biggest bottle-necks to be conquered before industrialization application. Big-size colloidal gold nanoparticles with strong surface plasma resonance are designed to composite with conjugated molecules, in order to realize effective fluorescence enhancement and stabilization. The uniform composition film of hydrophilic colloidal gold nanoparticles (particle diameter of 30 nm) and hydrophobic carbazole functionalized fluorene trimers has been obtained by direct mixing of their aqueous and THF solutions, which is determined by AFM. By the comparison of composition based on fluorene trimers with similar structures, we have found that peripheral carbazole group and molecular size of fluorene trimers play an important role in the balance of incompatible solubility, which is regarded as increasing solubility of fluorene trimers in mixed solvent, connecting AuNP and peripheral carbazole groups, and restraining aggregate of gold nanoparticle. This allows facile hydrophilic gold nanoparticle to disperse uniformly in hydrophobic-conjugated host. Our investigations show that fluorescence intensity of composition film is enhanced by 4 folds, and heat treatment (200°C for 4h) for the composition film does not induce the degradation of conjugated backbone without the appearance of low-energy emission band, demonstrating the prominent potency of gold nanoparticles in enhanced fluorescence and stability of conjugated molecules and polymers.     

Synthesis and Characterization of Fluorene-based Polymers Containing Electron-withdrawing Thiazolo Thiazole Unit

1 Results Low bandgap polymers can be used for pure red light emitting materials or solar cell materials.To make low bandgap polymers,we designed conjugated polymers with alternating sequences of the appropriate donor/acceptor units in the main chain.3-hexyl thiophene was used as a electron donating unit.For the electron accepting unit,we selected thiazolothiazole and bithiazole units having electron withdrawing property.Polyfluorene(PF) is the preferred conjugated polymer in light-emitting applications...     

Carbazole—containing light—emitting polymers：Properties of excited states

A series of light-emitting conjugated polymers alternatively involving carbazole and bivinylene arylene moieties in the main chain were synthesized via Wit-tig-Horner type copolymerization.The photoinduced charge transfer process relating to these polymers was investigated by using the technique of fluorescence spectroscopy.The interaction between excited copolymers and C60 in benzene solution was studied.The fluorescence quenching can be well described by the “sphere-of-action” mechanism.It is be-lieved that two basic steps are involved in the quenching process,i.e. the diffusion of excitation within the comjugated polymers and the dissociation of the exctions trapped by fullerene,The radius of the sphere-of-action can be related to the excitation diffusion length,which depends on the lifetime of the exciton.The dynamic fluorescence quenching of the copolymers by another quencher,1,4-dicyanobenzene(DCB) was also surveyed.Copolymers with different chain confor-mations show different temperature effects in the dynamic quenching.A planar conformation is beneficial for the quenching via bimolecular collision.     

Collapse of stiff conjugated polymers with chemical defects into ordered, cylindrical conformations

The optical, electronic and mechanical properties of synthetic and biological materials consisting of polymer chains depend sensitively on the conformation adopted by these chains. The range of conformations available to such systems has accordingly been of intense fundamental as well as practical interest, and distinct conformational classes have been predicted, depending on the stiffness of the polymer chains and the strength of attractive interactions between segments within a chain. For example, flexible polymers should adopt highly disordered conformations resembling either a random coil or, in the presence of strong intrachain attractions, a so-called 'molten globule'. Stiff polymers with strong intrachain interactions, in contrast, are expected to collapse into conformations with long-range order, in the shape of toroids or rod-like structures. Here we use computer simulations to show that the anisotropy distribution obtained from polarization spectroscopy measurements on individual poly[2-methoxy-5-(2'-ethylhexyl)oxy-1,4-phenylenevinylene] polymer molecules is consistent with this prototypical stiff conjugated polymer adopting a highly ordered, collapsed conformation that cannot be correlated with ideal toroid or rod structures. We find that the presence of so-called 'tetrahedral chemical defects', where conjugated carbon-carbon links are replaced by tetrahedral links, divides the polymer chain into structurally identifiable quasi-straight segments that allow the molecule to adopt cylindrical conformations. Indeed, highly ordered, cylindrical conformations may be a critical factor in dictating the extraordinary photophysical properties of conjugated polymers, including highly efficient intramolecular energy transfer and significant local optical anisotropy in thin films.     

Hyperbranched polymer-cored star polyfluorenes as blue light-emitting materials

Hyperbranched polymer-cored star polyfluorenes with high molecular weights and narrow molecular weight distribution were prepared by palladium-catalyzed one-pot Suzuki polycondensation of multi-functional cores and an AB-type monomer. The optical, electrochemical and thermal properties of the hyperbrenched polymer-cored star polymers were investigated. These polymers exhibited good thermal and color stability in solid state, and there was no significant blue-green emission after the polymers had been annealed in air for 2.5 h. Their three-dimensional hyperbranched structures could elfectively reduce the aggregation of the peripheral rigid linear conjugated polyfluorene chains.     

聚芴(PFs)制备和表征的研究进展

聚芴是一种重要共轭高分子材料,文章概述了可溶解性聚芴(或芴的寡聚物)的3种典型聚合方法,即FeCl3(三氯化铁)氧化法、镍催化法以及铂催化法合成聚芴,并按照分子链序列结构(交替共聚,嵌段工具,无轨共聚)的线索回顾了芴的共聚物的制备,简单介绍了目标产物的性质特征和对聚芴发光特性的影响。     

微孔有机聚合物

微孔有机聚合物是一种新型的多孔材料,在非均相催化、吸附、分离和气体存储等方面具有潜在的应用.它是最近几十年发展起来的,全部由有机分子的构建块组装而成的微孔（孔径小于2.0nm）固体.依据设计策略的不同,主要可以分成以下4种：（1）通过交联反应阻止链密堆积的超交联聚合物;（2）通过刚性和扭曲基团阻止链密堆积的自具微孔聚合物;（3）通过大共轭？-体系刚性结构组建的共轭微孔聚合物;（4）通过适宜的官能团发生可逆地缩合反应来制备的共价有机骨架聚合物.本文根据国内外的研究背景,重点介绍自具微孔聚合物和共轭微孔聚合物.     

论共轭聚合物的合成方法及其应用

π共轭聚合物因具有独特的光、电性能而引起了科学界的广泛关注。由富电子单元和缺电子单元构成的给一受电子模型聚合物由于其在太阳能电池、发光二极管、传感器等领域有着诱人的应用前景而受到科学界和商业界的青睐。本论文介绍共轭聚合物的特性及其合成方法,论述共轭聚合物在太阳能电池和发光材料中的应用。     

水溶性共轭聚合物对过渡金属离子的检测

通过对3种主链分别带有联吡啶、吡啶和苯的阴离子型水溶性聚对芳撑乙炔水溶液中加入不同价态的过渡金属离子,研究其紫外吸收和荧光发射谱图的变化,了解水溶性聚对芳撑乙炔产生荧光猝灭的机理.研究表明,过渡金属离子的价态会影响聚合物在水溶液的链积聚程度,并最终对共轭聚合物猝灭效应产生很大的影响.     

硅芴-芴共聚物的合成、表征和光电性能

合成了硅芴与芴的共聚物.系统研究了该新型共轭聚合物的溶解性、热稳定性、电化学性能、光物理性能和电致发光性能等.研究发现,无规嵌入少量具有高能隙、低LUMO能量的硅芴单元到聚芴主链中可有效调控聚合物的光电性能.     

Poly (9,9-dioctylfluorene- co-thiophene) End-capped with Gold Nanoparticles

1 Results Conjugated polymers have been widely studied for fabrication of polymeric light-emitting diodes (PLEDs) devices. While the copolymer of fluorene and thiophene has high luminescence and device efficiency,its photooxidation has yet to be suppressed in order to enhance the device stability. Adding stabilizer such as metal nanoshells or metal nanoparticles has been found to be an efficient method for suppressing photooxidation.In this lecture,poly(9,9-dioctylfluorene-alt-thiophene) (PDOFT) was syn...     

Highly sensitive biosensors based on water-soluble conjugated polymers

Conjugated, conductive polymers are a kind of important organic macromolecules, which has found applications in a variety of areas. The application of conjugated polymers in developing fluorescent biosensors represents the merge of polymer sciences and biological sciences. Conjugated polymers are very good light harvesters as well as fluorescent polymers, and they are also “molecular wires”.Through elaborate designs, these important features, i.e.efficient light harvesting and electron/energy transfer, can be used as signal amplification in fluorescent biosensors. This might significantly improve the sensitivity of conjugated polymer-based biosensors. In this article, we reviewed the application of conjugated polymers, via either electron transfer or energy transfer, to detections of gene targets, antibodies or enzymes. We also reviewed recent efforts in conjugated polymer-based solid-state sensor designs as well as chip-based multiple target detection. Possible directions in this conjugated polymer-based biosensor area are also discussed.     

梯型导电高分子几何构型的AM1优化

采用齐聚物法（Ｏｌｉｇｏｍｅｒａｐｐｒｏａｃｈ）对π共轭的梯型导电子分子的几保构型进行ＡＭ１优化，并对优化结果进行了详细的讨论，发现在π共轭的高分子链中（４ｎ＋２）规则和端基效应对分子链的几何构型起着十分重要的作用。     

Control of conformational and interpolymer effects in conjugated polymers.

The role of conjugated polymers in emerging electronic, sensor and display technologies is rapidly expanding. In spite of extensive investigations, the intrinsic spectroscopic properties of conjugated polymers in precise conformational and spatial arrangements have remained elusive. The difficulties of obtaining such information are endemic to polymers, which often resist assembly into single crystals or organized structures owing to entropic and polydispersity considerations. Here we show that the conformation of individual polymers and interpolymer interactions in conjugated polymers can be controlled through the use of designed surfactant poly(p-phenylene-ethynylene) Langmuir films. We show that by mechanically inducing reversible conformational changes of these Langmuir monolayers, we can obtain the precise interrelationship of the intrinsic optical properties of a conjugated polymer and a single chain's conformation and/or interpolymer interactions. This method for controlling the structure of conjugated polymers and establishing their intrinsic spectroscopic properties should permit a more comprehensive understanding of fluorescent conjugated materials.     

含共轭三键的聚合物的掺杂机理和导电特性的研究

以聚丁（对甲苯硫酸）－２,４－己炔－１,６－二醇酯（ＰＤＡ－ＴＳ）为例,探讨了含共轭三键的聚合物的掺杂和导电特性的研究,对其微观掺杂机制,在比较现有的掺杂模型的基础上,提出了新的掺杂模型。     

导电聚合物的电化学性质

综述了几种有代表性的导电聚合物——聚吡咯、聚苯胺、聚噻吩等的电化学特性及其电化学掺杂／脱掺杂反应的机理,介绍了聚对苯撑乙烯(PPV)等光电活性共轭聚合物的循环伏安特性及其HOMO和LUMO能级的电化学表征方法;还对导电聚合物的电化学稳定性以及取代基对共轭聚合物电子结构的影响进行了讨论．     

星状共聚物C70（CH3）x（PAN）x的合成及其热解行为

通过活性的末端丁基聚丙烯腈（ＰＡＮ）与Ｃ７０在乙醚／甲苯混合溶剂中的反应，并用碘甲烷处理，制定新型星状共聚物［Ｃ７０（ＣＨ３）ｘ（ＰＡＮ）ｘ］。该聚合物在结构上存在着Ｃ７０核与多条ＰＡＮ链结合，变温傅里叶红外光谱测试结果表明：随着该聚合物热解过程进行，聚合物中腈基逐渐消失而出现共轭Ｃ＝Ｎ链，并形成芳环。另外末端丁基聚丙烯腈经Ｃ７０化学修饰后热稳定性有所提高。     

Self-Assembled Conjugated Polymer Nanometer Scale Devices

1 Introduction Nanometer scale devices, as the next generation devices of electronics, have got a worldwide attention and rapid development recently. Simultaneously, conjugated polymers have been applied in organic electronics successfully because of their outstanding electronic-photonic properties. However, as far as we know few reports have dealt with the fabrication of nanometer scale devices by using conjugated polymers, although the combination of nanometer scale devices and polymers will…     

含N-己基吩噻嗪和N-己基咔唑基团的联苯乙烯类有机发光材料的合成及其性能研究

 联苯乙烯类衍生物被认为是一类具有实用价值的蓝光电致发光材料,它具有较优异的综合性能。 以联苯乙烯为基础,利用Wittig-Horner反应分别引入N-己基吩噻嗪和N-己基咔唑基团,合成了两种联苯乙烯衍生物。利用核磁共振氢谱（ 1H NMR）、傅立叶红外光谱（FT-IR）、质谱（MS）和元素分析（EA）对所合成产物进行了化学结构的表征;利用紫外吸光光度法（UV）、荧光分光光度法（PL）、热重分析（TGA）、示差扫描量热法（DSC）、热台偏光显微镜（PLM）和X-射线衍射（XRD）对产物的性能进行了初步的表征。结果表明：所 合成的两个化合物在紫外光激发下均能发射高亮度荧光;具有较高的热稳定性;两个化合物均不能结晶,易溶于二氯甲烷等有机溶剂,并且容易成膜,非常适合于旋涂法制备OLED器件;其中含 吩噻嗪基的化合物在熔融或冷却过程中均能观察到近晶A型液晶织构。     

手性联二萘侧基聚(3,3'-联咔唑对苯二腈)的合成及其聚集诱导发光和圆偏振发光性能研究

以手性联二萘(BINOL)取代的2, 3-二氟对苯二腈和3, 3'-联咔唑为单体,通过碳-氮偶联反应得到一对共轭聚合物(R)-P1和(S)-P1,并且通过1H NMR与13C NMR、凝胶渗透色谱(GPC)、热重分析(TGA)、荧光发射光谱(PL)、圆二色谱(CD)和圆偏振发光(CPL)光谱等对聚合物的化学结构、分子量、热稳定性以及光物理性质等进行了表征.结果表明:该聚合物具有明显的聚集诱导发光(AIE)性质;手性联二萘侧基能有效地诱导共轭主链的微环境,使该聚合物具有手性活性,且表现出CPL特性.