Photoactive Nanostructures of Polypyrrole

The creation of nanostructures of the photoactive polymer polypyrrole (PPy) on glass substrates with the spin‐coating method is described. No additional post‐production treatment is necessary to obtain uniformly distributed photoactive nanostructures on macroscopically scaled substrates. Based on X‐ray reflectivity measurements, the critical solution concentration of PPy below which these nanostructures develop is determined. The PPy nanostructures are displayed with atomic force microscopy (AFM) measurements, which prove that the nanostructures form directly on the substrate. With UV/Vis spectroscopy the absorption behavior of the nanostructures is probed in comparison to PPy films and PPy solutions. A linear dependence of the absorption of the nanostructure on the surface coverage measured with AFM is detected. The influence of confinement on the conjugation length results in a modified absorption behavior of the nanostructures.     

纳米石墨薄片/聚吡咯复合材料的制备及导电性能

膨胀石墨经过超声处理制备了纳米石墨薄片。以其为导电填料，对甲苯磺酸为掺杂剂，FeCl₃·6H₂O为氧化剂，引发吡咯单体发生原位聚合，制备出纳米石墨薄片/聚吡咯(NanoGs/PPy)复合材料。利用红外光谱(FTIR)、扫描电镜(SEM)和透射电镜(TEM)表征了材料的组成和结构。结果表明，石墨薄片被聚吡咯完全包覆；并且以纳米级尺寸分散在聚吡咯基体中。热失重(TG)分析和电导率测试结果表明，复合材料的耐热性能和导电性能较纯聚吡咯有所提高。     

表面活性剂对导电聚吡咯性能的影响

采用十六烷基溴化铵（CTAB）、十二苯磺酸（DBSA）、十二烷基硫酸钠（SDS）3种表面活性刘为软模板,过硫酸铵为氧化剂,在0℃冰水浴条件下制备导电聚吡咯。通过改变表面活性剂的种类和用量,考察其对聚吡咯形貌和性能的影响。用FTIR、XRD、SEM等对聚吡咯材料进行表征。研究表明：表面活性剂和PPy存在一定程度上的相互协同作用,添加表面活性剂能够直接调整聚吡咯分子的形貌;掺杂DBSA、SDS可合成球状结构聚吡咯,掺杂CTAB可合成棒状结构的聚吡咯,并且当”（PPy）：n（CTAB）-5时,合成的聚吡咯导电性能最好。     

顺序加料法制备聚苯胺与聚吡咯复合物及其电化学电容性能

以顺序加料原位聚合法化学氧化制备了聚吡咯(PPy)和聚苯胺(PANi)的复合物.采用SEM、红外光谱表征其结构,采用电化学工作站测试其超级电容性能.结果表明:制得的聚苯胺与聚吡咯的复合物,形成了二次结构;复合物的循环伏安特性曲线均接近于理想的矩形,恒流充放电曲线基本为线性,呈现双电层电容;PANi-PPy和PPy-PANi复合物的最高比电容分别达到227.6、195.5 F/g.     

过渡金属一取代Keggin结构钼磷酸盐掺杂的聚吡咯的制备、表征与导电性研究

０引言有机高分子－多酸导电聚合物是８０年代末兴起的一类新型有机－无机杂化材料。由于它兼有无机组分和有机聚合物基块的性能，并能衍生出新的导电性、光学性、耐摩擦、力学性能、功能梯度等，它现已成为材料科学和化学科学研究的前沿课题之一犤１犦。多酸是一类含有氧桥的多核配合物，具有强酸性、强氧化性、优良的催化活性、光致变色、电致变色性及高质子导电性等，可作为构建有机－无机杂化材料的基块犤２，３犦。聚吡咯是一类有机高分子，其合成简便、空气稳定性好、易于掺杂，通过掺杂可形成高电导率的高分子材料。若将多酸掺杂聚吡…     

Bio‐Inspired Dopamine Functionalization of Polypyrrole for Improved Adhesion and Conductivity

We report the functionalization of polypyrrole (PPy) with a “sticky” biomolecule dopamine (DA), which mimics the essential component of mussel adhesive protein. PPy is one of the most promising electrically conductive polymers with good biocompatibility. The research findings reveal that the DA functionalization enhances the dispersibility and stability of PPy in water and its film adhesion to substrate surface significantly. The electrical conductivity of PPy increases to a maximum value and then decreases with the increasing DA concentration. An optimal DA to pyrrole (Py) mole ratio is found to be between 0.1 and 0.2, at which both conductivity and adhesion of DA‐functionalized PPy has been improved.

     

表面活性剂水溶液的电导率研究方法和一些特征数据的提取

电导率是研究水溶液中离子型表面活性剂胶束化行为的重要方法,本文总结了这个灵敏测定技术,分别着重讨论了两个重要特征参数(临界胶束浓度(cmc)和胶束的反离子解离度(α))的提取方法、电导率曲线某些特殊情况的分析以及预胶束化行为的研究,这对运用电导率技术研究当前不断增多的具有强分子间相互作用的表面活性剂(例如Geminis)体系具有参考价值.     

Optimization of Polypyrrole Chemical Synthesis by Heat Flow Reaction Calorimetry

Chemical polymerization of pyrrole (Py) was carried out in a reaction calorimeter by using FeCl₃ or CuCl₂ as an oxidant in an acetonitrile medium. The formation heat of polypyrrole (PPy), determined under a wide range of reactant concentrations and reaction temperatures, is directly related to the PPy yields and to the degree of polymerization. Due to the negative values of both the entropy and enthalpy of the reaction the gravimetric yield is inversely related to the temperature and directly to the Py concentration. The yields to the PPy and the related reaction heats, are close to zero when the ceiling temperatures are reached (T_ceil=348 K for Fe-doped and T_ceil=313 K for Cu-doped PPys). It was observed that a ceiling concentration corresponds to each ceiling temperature and only light oligomers are formed if Py concentration is too low. The electric conductivity values of the products were also determined and a direct relationship to the yields was found as well. The highest electric conductivity value (C=0.6 S cm^–1) was related to the PPy fresh synthesized from a 0.017 M Py solution.This revised version was published online in November 2005 with corrections to the Cover Date.     

阴离子与非离子表面活性剂复配体系反胶团的电导研究

在SDS/Tween60/正己醇/环己烷/水形成的反胶团复配体系中,电导率(κ)与水和表面活性剂的摩尔比(W0)关系曲线上存在最大值,随着复配体系中SDS的摩尔分数(xSDS)增大,最大增溶水量(W0,max)向W0值更大的方向移动.xSDS≤0.5时,随着xSDS的增大,W0,max所对应的电导率值增大;xSDS≥0.5时,其电导率值减小.在AOT/Tween60/环己烷/水体系中,出现了与SDS/Tween60/正己醇/正己烷/水体系类似的现象,但W0,max所对应的电导率值,随着xAOT的增大而增大,不会出现极大值,两者的差异主要是由于助表面活性剂醇的影响.在SDS/TritionX-100/正己醇/环己烷/水体系中也印证了该结论.     

离子液体中吡咯的电化学聚合及性质研究

以1-丁基-3-甲基咪唑六氟磷酸盐离子液体作为溶剂和支持电解质,分别在铂电极和导电玻璃电极上电化学聚合得到了聚吡咯,聚合过程中发现,在离子液体中聚合的循环伏安图,其电流的变化和传统有机溶剂中的不同,通过交流阻抗技术研究了修饰电极的电化学性质,采用在线紫外、拉曼、红外谱对聚吡咯进行了光谱表征,得到了聚吡咯的特征峰,采用扫描电镜研究了聚合物的形貌。最后将修饰电极应用到了对对苯二酚的催化反应当中,显示了一定的催化作用。     

质子型离子液体N,N-二甲基乙醇胺丙酸盐的密度、粘度及电导率

在283.15-333.15 K温度范围内, 测量了质子型离子液体N,N-二甲基乙醇胺丙酸盐(DMEOAP)的密度、粘度及电导率. 讨论了温度对密度、粘度和电导率等物理化学参数的影响. 通过经验和半经验方程得到了该离子液体的热膨胀系数、分子体积、标准摩尔熵及晶格能等热力学性质参数. 由电导率和密度计算出了该离子液体的摩尔电导率. 利用Vogel-Fulcher-Tamman (VFT)方程, 将测量的动力粘度和电导率对温度拟合, 得到了动力粘度和电导率随温度变化方程式.并通过Walden规则, 建立了粘度与摩尔电导率之间的联系.     

聚吡咯在超级电容器中的应用

聚吡咯以其制备简单、掺杂可逆、环境友好、导电率高、比电容大、具有良好的成膜性而备受关注。特别是在作为超级电容器、二次电池等换能设备电极材料领域中前景广阔。文章简略地介绍了超级电容器的双电层电容和法拉第赝电容产生的机理,概述了近年来聚吡咯与金属氧化物、炭材料等通过化学法、电化学法以及界面化学法等新型手段制备聚吡咯电极的研究进展。     

电导法确定二元体系中离子的浓度

本文从电化学基本原理出发,推导出稀溶液中二元混合组分的电导与各组分当量浓度的关系,并通过测定纯组分的电导－当量浓度标准曲线,来确定二元混合组分的标准曲线在对其中一组分浓度确定的基础上,可很容易计算另一组分的浓度。该法简便、快速,有望成为化学分析和仪器分析的一个很好的补充。     

Characteristics of the ring stretching of oxidized polypyrrole on the surface-enhanced Raman spectrum

In this study, polypyrrole (PPy) films were electropolymerized under different preparation conditions on rough gold substrates. The peak shown at the higher frequency of the double peaks at about 1329 and 1386 cm^–1 in surface-enhanced Raman scattering of PPy was initially assigned to the ring stretching of oxidized PPy. A systematic study was carried out to confirm this assignment. It was found that the conductivity of PPy was strongly related to and increased with this Raman peak intensity of oxidized PPy. Meanwhile, the normalized relative intensities of this Raman peak for various PPy films are consistent with their corresponding doping levels. Electronic Publication     

聚吡咯薄膜在超临界CO_2与离子液体两相体系中的电化学合成

首次在超临界CO2与离子液体两相体系中实现了聚吡咯（PPyr）薄膜的电化学合成.与纯离子液体相比,该体系中合成的PPyr膜具有均匀平滑的表面.随着CO2压力的增加,膜的生长速度减慢,膜的表面变得更加均匀平滑.     

反应条件对乳液法自组装合成氧化锰纳米粒子结构、形貌和尺寸的影响

通过改变反应物物质的量比、分散相与连续相体积比、反应体系温度和煅烧后处理温度,研究了反应条件对乳液法自组装合成氧化锰纳米粒子结构、形貌和尺寸的影响.结果表明:当高锰酸钾与油酸物质的量比在1∶5～1∶1之间时,形成蜂窝状纳米粒子和空心纳米粒子;当分散相(油酸)与连续相(水)的体积比为4∶200时,形成良好的空心球纳米结构;反应体系温度升高不利于产物的洗涤;不同温度的煅烧后处理不仅影响氧化锰纳米粒子的形貌,而且影响其结晶度和晶型.     

取代聚吡咯自掺杂导电机理的理论研究

自掺杂导电高分子材料均溶于水,其水溶液容易在各种基质上浇注成膜,且加工方便,因而引起了人们的极大兴趣,然而有关其理论研究尚未见报道。 聚3-甲基-4-羧酸吡咯(PMPC)是水溶性自掺杂导电高分子材料中的一种,它可由3-甲基     

电聚合导电聚吡咯的合成研究

用电化学法将吡咯单体聚合在电极上，于不同支持电解质的水溶液中得到聚吡啶薄膜。研究了电解质浓度、电解质阴离子种类及聚合时间对聚吡咯薄膜导电性能的影响。     

Evaluation of the Conductivity of the Polypyrrole Film via Its CC Bonds Stretching on Surface‐Enhanced Raman Spectrum

In this study, the conductivities of various polypyrrole (PPy) films were evaluated via the corresponding surface‐enhanced Raman scattering (SERS) spectrum and X‐ray photoelectron spectroscopy (XPS). The results indicate that the peak position of C?C bonds stretching of PPy obtained from the SERS spectrum shows more exactly both qualitatively and quantitatively representing the conductivity of PPy than the N⁺/N ratio or the doping level obtained from the XPS analysis does. Namely the peak position of C?C bonds stretching of PPy monotone decreases to a lower frequency side with the increase of the conductivity of PPy. Furthermore, a satisfactory correlated equation between them was obtained. On the contrary, neither the N⁺/N ratio nor the doping level can be qualitatively reflective on the corresponding conductivity of PPy.     

Effect of Electrolytes on Redox Reactivity of Polypyrrole

Doping and dedoping characteristics of polypyrrole (PPy) formed electrochemically have been examined by means of energy-dispersive X-ray spectroscopy (EDS). Dodecylsulfate ions (DS⁻) and perchlorate ions (ClO⁻₄) were embedded simultaneously in PPy when both ions were present on the polymerization of pyrrole. Sequential formation of PPy in the single dopant system allowed PPy/ClO₄ to grow in the bulk of PPy/DS but not vice versa. DS⁻ was embedded not to leave the polymer on reduction but ClO⁻₄ moved in and out of the polymer on redox reaction. Cyclic voltammetry was employed to determine the redox reactivity of PPy in different electrolyte systems. NaClO₄ was a better electrolyte for cyclic redox reaction than LiClO₄ or KClO₄. NaCl was a good electrolyte for cyclic redox reaction but Cl⁻ failed to penetrate in the PPy/DS bulk on reoxidation. The cyclic redox reactivity lasted longest when PPy/DS was redox-cycled sequentially in the NaCl electrolyte system and then in the NaClO₄ system. © 1997 John Wiley & Sons, Ltd.