导电聚合物单体的光电聚合

苯胺、吡咯和噻吩等是重要的导电聚合物单体.光照可促进低聚物的形成,电化学技术可方便地实现单体的电聚合.目前,有关导电聚合物单体的光电聚合的报导还很少.本文研究征水溶液中、铂金属基底上,苯胺、吡咯和噻吩等单体的光电聚合过程.     

硫醇自组装膜对金电极上吡咯电化学聚合的影响

用电化学聚合法在多种烷基硫醇自组装膜修饰金电极上制备了聚吡咯.通过计时安培法、循环伏安法和交流阻抗技术研究了自组装膜的烷基链长和端基功能团对吡咯聚合过程和性质的影响.当自组装膜较完美时,聚吡咯沉积在自组装膜表面;而当自组装膜有一定缺陷时,吡咯在针孔处成核,然后继续生长并完全覆盖在自组装膜表面.研究结果表明,烷基硫醇的链越短,吡咯聚合越容易;疏水的烷基硫醇自组装膜有利于聚吡咯在电极表面的生长.     

双-[2-吡咯(乙氧基)]乙烷的合成及其电化学聚合

以吡咯和二缩三乙二醇为原料合成了N取代吡咯衍生物单体--双-[2-吡咯(乙氧基)]乙烷,并用循环扫描伏安技术研究了该单体的电化学聚合过程.结果表明:在乙腈/高氯酸锂溶液中,双-[2-吡咯(乙氧基)]乙烷在铟锡氧化物导电玻璃(ITO)、Pt、Au、玻璃碳、石墨电极上均能顺利发生反应,形成一定厚度的聚合物膜.但聚合速率、膜的结构、膜的颜色有差异.溶剂水对聚合有明显影响.形成的聚合膜具有良好的电化学稳定性.     

水介质中吡咯的电化学聚合反应

研究了扫描电位上限对循环伏安法制备聚吡咯膜性能的影响，吡咯在水溶液中于玻碳电极表面化学聚合的起始电位为0．58V，在聚吡咯（Ppy）修饰电极表面聚合的起始电位为0．55V，当聚合电位上限在0．80V以上时，Ppy的氧化还原反应可逆性变差，同时，氧化电位过高将导致Ppy膜导电性能下降；研究了聚合介质对循环伏安法制备导电聚吡咯膜的影响，实时观察了吡咯（Py）聚合过程溶液中质子含量的动态变化，发现Py聚合伴随有质掺杂←→释放过程；结合Ppy膜的元素分析、ESR分析和IR光谱分析，总结出了水介质中电化学聚合高导电性聚吡咯膜的条件。     

导电高分子材料电化学合成过程中的计量化学关系

导电高分子材料可以通过电化学方法合成,在合成过程中,电解液中的阴离子以一定比例作为反离子结合在聚合物 中,然后沉积在电极表面.本文以聚吡咯为例,对此过程进行了计量化学探主坟,导出了生成的聚合重量与反应中消耗的电量及反离子大小和比例间的关系.十二磺酸聚吡咯、扁桃酸聚吡咯、讥氯酸聚吡咯与氯化聚吡咯的电化学合成证实了以上关系.实验与计算表明,氯化聚吡咯中由于反离的分子量接近单体分子量的1/2,故生成的聚合物重量与反离子在聚合筘的比例无关.     

呲咯电化学聚合的现场ESR波谱和Raman光谱研究

本文采用ESR波谱和Raman光谱方法现场(in situ)研究吡咯在水溶液中的电化学聚合过程。ESR结果显示,形成的聚吡咯(PP)膜的氧化态结构(PP++)对吡咯的氧化聚合具有电催化活性;由此可解释吡咯在PP膜上更易聚合的实验事实。利用表面增强共振Raman散射(SERRS)效应,可研究PP膜在金电极上的形成和增厚过程的结构。光照下吡咯的电化学聚合电位显著降低(约300mV),此光催化作用可望在制备新型有机器件等方面获得应用。     

聚吡咯为基底的葡萄糖酶微电极的研究

本文将聚吡咯(PPy)修饰的铂微电极以牛血清白蛋白(BSA)为载体,用戊二醛与萄葡糖氧化酶(GOD)交联,制成了萄葡糖酶微电极(GOD/PPy/Pt)。电极的寿命可达21天。萄葡糖浓度在1.0×10~(-4)～3.0×10~(-3)mol/L范围内有线性关系。     

磷钼杂多酸—聚吡咯膜修饰碳纤维微电极的制备及其电化学性能研究

用电化学方法将磷钼杂多酸催化剂固定在导电聚吡咯膜电极上，从而制得具有表面功能的磷钼杂多酸掺杂的聚吡咯膜修饰碳纤维微电极。该电极既保持了磷钼杂多酸的电化学活性和电催化性能，又具有良好的稳定性，在酸性水溶液中不仅能催化还原ＣｌＯ３而且对ＮＯ６－２离子有有更显著的电催化还原作用。     

聚吡咯纳米线的恒电位合成及形貌分析

采用恒电位法,直接在石墨电极表面快速合成聚吡咯纳米线,并重点研究了聚吡咯纳米线的生成过程及形貌变化规律。结果表明,聚吡咯纳米线的生成包括成核和生长过程,纳米线的形貌随聚合条件的不同而变化,直径随聚合电位、吡咯单体浓度、电解质浓度的升高而增大,这是由于不同聚合条件下聚吡咯的成核速率不同引起的。     

聚吡咯并[3,4-c]吡咯的电子结构及导电性研究

采用密度泛函(DFT)方法在6-31g(d)水平下研究了聚吡咯和聚吡咯并[3,4-c]吡咯, 以及它们的单体和低聚物的电子结构. 对中心键的键长、电荷密度以及Weberg键级的研究表明, 随着主链聚合度的增加, 其共轭性增强. 对聚合物还进行了能带结构和态密度分析. 结果发现, 在3位聚合的并环化合物具有最优的导电性能, 其能隙仅有0.25 eV, 可以作为潜在的导电聚合物材料.     

Matrix polymerization on polycationic backbones: A continuous method for following the polymerization kinetics

A novel method of following polymerization kinetics in dilute solutions of ionic monomers is described. The method, based on conductimetry, is very well adapted to follow polymerization of ionic species in very dilute solutions, in micellar solutions, or at interfaces, i.e., in all systems in which the polymerization process involves a shift in ionic equilibria. The method is applied to matrix polymerization of p-styrene sulfonate–(2,2,2)4-ionene complex and yields results in full agreement with the standard spectroscopic method frequently used in such systems. The conversion curves obtained by conductimetry are satisfactorily explained by Manning's ion condensation model and are in agreement with a previously proposed mechanism, based on ion condensation theory, for matrix polymerization of ionized monomers on polyelectrolytes.     

Fluorescence Self-Reporting Precipitation Polymerization Based on Aggregation-Induced Emission for Constructing Optical Nanoagents

Precipitation polymerization is becoming increasingly popular in energy, environment and biomedicine. However, its proficient utilization highly relies on the mechanistic understanding of polymerization process. Now, a fluorescence self-reporting method based on aggregation-induced emission (AIE) is used to shed light on the mechanism of precipitation polymerization. The nucleation and growth processes during the copolymerization of a vinyl-modified AIEgen, styrene, and maleic anhydride can be sensitively monitored in real time. The phase-separation and dynamic hardening processes can be clearly discerned by tracking fluorescence changes. Moreover, polymeric fluorescent particles (PFPs) with uniform and tunable sizes can be obtained in a self-stabilized manner. These PFPs exhibit biolabeling and photosensitizing abilities and are used as superior optical nanoagents for photo-controllable immunotherapy, indicative of their great potential in biomedical applications.     

丙烯酰胺在聚乙二醇水溶液中的聚合动力学

用改进溴法对丙烯酰胺 (AM)在聚乙二醇 (PEG)水溶液中聚合动力学进行研究 .在单一和氧化还原引发体系中分别考察了引发剂、单体和PEG用量、不同HLB值乳化剂以及聚合温度等因素对动力学的影响 .得到AM聚合速率与过硫酸铵 (APS)浓度的 0 91次方成正比 ;单一APS和APS 三乙醇胺 (TEA)氧化还原引发体系中的AM聚合表观活化能分别为 96 1和 4 2 3kJ mol.     

水溶液中噻吩的电化学聚合成膜

本文研究水溶液中噻吩的电化学聚合。高酸度水溶液中噻吩先经历化学低聚反应,低聚合物可在较负的电位阳极氧化成膜。     

Kinetics of surface‐initiated atom transfer radical polymerization

Although atom transfer radical polymerization (ATRP) is often a controlled/living process, the growth rate of polymer films during surface‐initiated ATRP frequently decreases with time. This article investigates the mechanism behind the termination of film growth. Studies of methyl methacrylate and methyl acrylate polymerization with a Cu/tris[2‐(dimethylamino)ethyl]amine catalyst system show a constant but slow growth rate at low catalyst concentrations and rapid growth followed by early termination at higher catalyst concentrations. For a given polymerization time, there is, therefore, an optimum intermediate catalyst concentration for achieving maximum film thickness. Simulations of polymerization that consider activation, deactivation, and termination show trends similar to those of the experimental data, and the addition of Cu(II) to polymerization solutions results in a more constant rate of film growth by decreasing the concentration of radicals on the surface. Taken together, these studies suggest that at high concentrations of radicals, termination of polymerization by radical recombination limits film growth. Interestingly, stirring of polymerization solutions decreases film thickness in some cases, presumably because chain motion facilitates radical recombination. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 41: 386–394, 2003     

Assembly of multilayered films using well-defined, end-labeled poly(acrylic acid): influence of molecular weight on exponential growth in a synthetic weak polyelectrolyte system

We report on the influence of polyanion molecular weight on the growth and structure of multilayered thin films fabricated from poly(allylamine) (PAH) and well-defined, end-labeled poly(acrylic acid) (PAA) synthesized by atom transfer radical polymerization. We observed striking differences in the growth of PAH/PAA films fabricated using well-defined PAA compared to films fabricated using higher molecular weight, commercially available PAA. Past studies demonstrate that the thicknesses of PAH/PAA films increase as linear functions of the number of PAH and PAA layers deposited over a broad range of pH (e.g., from pH 2.5 to 4.5). We observed the thicknesses of films fabricated using solutions of PAH and PAA adjusted to pH 7.5 and 3.5, respectively, to increase in a nonlinear manner. Films fabricated using well-defined, low molecular weight samples of PAA under these conditions increased in thickness exponentially. Experiments using samples of PAA having substantially non-overlapping molecular weight distributions demonstrated a clear relationship between the molecular weight of PAA and rates of film growth. We also used confocal microscopy, in combination with fluorescently end-labeled samples of PAA, to characterize the location of PAA in these assemblies. The results of these experiments, when combined, support the general conclusion that PAA is able to penetrate or diffuse into these films over large distances during assembly. The mechanism of growth for these films thus appears similar to that recently reported for the exponential growth of films fabricated using a variety of biologically relevant polyelectrolytes. The use of living/controlled methods of polymerization to synthesize well-defined samples of PAA facilitates an interpretation of these differences in film behavior as arising largely from differences in polymer molecular weight and polydispersity. This work provides insight into the assembly and structure of a well-studied weak polyelectrolyte film system and illustrates the potential of living/controlled methods of polymerization to contribute to the characterization and understanding of the physical properties of these ionically cross-linked materials.     

聚苯胺分子印迹膜电化学传感器检测氯霉素

以苯胺为功能单体和交联剂,氯霉素(chloramphenicol,CAP)为模板分子,采用电化学聚合法(循环伏安法)在金电极上合成了对CAP具有快速响应能力的聚苯胺分子印迹膜;结合差示脉冲伏安法建立了针对氯霉素的检测方法,并将所制备的聚苯胺分子印迹膜用作电化学传感器以测定氯霉素眼药水中的氯霉素.结果表明,所制备的聚苯胺分子印迹膜具有制备简单、响应快速、灵敏度高、再生性能良好等特点;其对氯霉素眼药水中的氯霉素的检测结果令人满意,有望用于实际样品中氯霉素的检测.     

The Electrochemical Polymerization of Thiophene in Aqueous Sotations of an Acid

People are more and more interested in polythiophene because of its night stability.At present,organic solvent system is still commonly used in electrochemical polymerization of thiophene and the related electrochemical studies.However,it is more practical to use aqueous solutions instead of organic solvents.The electrochemical polymerization of thiophene in aqueous solution of acid is discussed in this paper.In highly concentrated acidic solution,thiophene first undergoes low polymerization,and then the low polymer can be oxidized at the comparatively negative potential to form film.     

Fluorescence Self‐Reporting Precipitation Polymerization Based on Aggregation‐Induced Emission for Constructing Optical Nanoagents

Precipitation polymerization is becoming increasingly popular in energy, environment and biomedicine. However, its proficient utilization highly relies on the mechanistic understanding of polymerization process. Now, a fluorescence self‐reporting method based on aggregation‐induced emission (AIE) is used to shed light on the mechanism of precipitation polymerization. The nucleation and growth processes during the copolymerization of a vinyl‐modified AIEgen, styrene, and maleic anhydride can be sensitively monitored in real time. The phase‐separation and dynamic hardening processes can be clearly discerned by tracking fluorescence changes. Moreover, polymeric fluorescent particles (PFPs) with uniform and tunable sizes can be obtained in a self‐stabilized manner. These PFPs exhibit biolabeling and photosensitizing abilities and are used as superior optical nanoagents for photo‐controllable immunotherapy, indicative of their great potential in biomedical applications.