导电聚苯胺/TiO_2微/纳米球的制备及其结构表征

采用具有八面体形貌的氧化亚铜为模板,制备了聚苯胺/TiO2(PANI/TiO2)微/纳米球,TiO2纳米粒子很均匀地分散在聚苯胺中.研究了不同TiO2/苯胺(TiO2/ANI)摩尔比对PANI/TiO2复合物的结构、形貌和电学性能的影响.实验结果表明,随着TiO2/ANI摩尔比的增加,PANI/TiO2复合物的直径逐渐减小,当TiO2/ANI摩尔比为0.16时,复合物的平均直径为373nm,而当TiO2/ANI摩尔比增加到1.6时,复合物的平均直径降到80nm.PANI/TiO2复合微/纳米球的电导率随着TiO2/ANI摩尔比的增加先升高后降低,当TiO2/ANI摩尔比达到1.6时,电导率由10-4S/cm提高到100S/cm,达到最大值.产物的形貌和结构分别采用扫描电镜、透射电镜、红外吸收光谱和X-射线衍射等手段进行了表征.     

Dispersible polyaniline nanoparticles in aqueous poly(styrenesulfonic acid) via the interfacial polymerization route

Water-dispersible nanoparticles of polyaniline (PANI) have been conveniently synthesized via the interfacial polymerization route using chemical oxidative polymerization of aniline (ANI) with ammonium peroxodisulfate in aqueous poly(styrenesulfonic acid) (PSS). Various molar feed ratios of ANI/PSS were employed to attain highly dispersible PANI nanoparticles. PSS was used as an anionic dopant and as a template for the formation of PANI nanoparticles. The dispersed PANI nanoparticles were characterized using a Zetasizer, transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS). Functional group analysis and the thermal stability of PANI particle dispersions were examined using FT-IR, UV-visible spectroscopy, and thermogravimetry analysis. The particle size of PANI-PSS nanoparticles was controlled by tuning the molar feed ratio of ANI/PSS. A uniform size distribution was obtained with the particle size of 5-15 nm for ANI/PSS ratios less than 1/1.     

Study of the chemical copolymerization of 2-aminoterephthalic acid and aniline.: Synthesis and copolymer properties

Aniline (ANI) and 2-aminoterephthalic acid (2ATA) copolymers, with different compositions, were prepared by chemical oxidative polymerization varying the feed ratio. The new materials have been characterized by techniques such as XPS, FTIR, Raman spectroscopies and thermal analysis. It has been checked that 2ATA units are included in the polymer backbone. Different properties have been studied as solubility, conductivity, optical absorption, fluorescence and electroactivity. The copolymers are soluble in aqueous alkaline medium and show clear electroactivity in aqueous acid medium.     

高强度聚乙烯醇/聚苯胺/聚吡咯/TiO2导电杂化水凝胶的制备与性能

本文以聚乙烯醇(PVA)、苯胺(ANI)、吡咯(Py)及钛酸丁酯(TBOT)为原料,通过溶胶-凝胶法、原位氧化聚合法及冷冻-融溶法一步得到聚乙烯醇/聚苯胺/聚吡咯/TiO 2(PVA/PANI/PPy/TiO 2)杂化水凝胶。结果表明,该杂化水凝胶具有优异的力学性能和导电性能。当n(ANI)∶[KG-*3/5]n(Py)=8∶[KG-*3/5]2(TBOT体积为100μL)时,其压缩强度高达2.45 MPa。同时,在外加电源的作用下,该凝胶能够使灯泡发光。当n(ANI)∶[KG-*3/5]n(Py)=2∶[KG-*3/5]8(TBOT体积为150μL)时,杂化水凝胶的电导率(0.25 S/m)最好。该杂化水凝胶有望广泛地应用在柔性可穿戴电子器件、安全离子电池、传感器和生物器件等领域。     

静电纺丝法制备聚丙烯腈/聚苯胺复合纳米纤维及其表征

利用静电纺丝技术,以聚丙烯腈(PAN)和苯胺(ANI)为前驱物,用过硫酸胺(APS)溶液在低温下缓慢氧化聚合,制备了PAN/PANI复合纳米纤维,直径约500 nm.通过扫描电子显微镜(SEM)、红外光谱(FTIR)、X射线衍射(XRD)和激光拉曼(RAMAN)光谱仪等测试手段对材料的形貌和结构进行了表征.探讨了材料制备过程中影响纤维形貌、尺寸、均匀度的因素和PANI含量对复合纤维导电性能的影响,结果表明,PAN浓度、ANI的加入量和电压是影响纤维特性的主要因素;PANI在PAN基体中呈纳米尺寸分布,复合纳米纤维具有良好的导电性能,导电率可达10-2S/cm.     

FeCl_3/APS复合氧化剂对乳液法合成聚苯胺动力学行为的影响

采用石英晶体微天平(QCM)技术,探讨了以三氯化铁(FeCl3)和过硫酸铵(APS)为复合氧化剂,十二烷基苯磺酸(DBSA)为乳化剂和掺杂剂时,苯胺(An)的乳液聚合动力学行为;并通过对产物的循环伏安分析,初步优化了聚合反应条件.结果表明,An的乳液聚合反应对复合氧化剂、An以及DBSA分别为1,0.5和0.5级.各种条件下的循环伏安(CV)图都显示出PAn的三对氧化还原特征峰.当FeCl3与APS物质的量比为2∶1;氧化剂总量与苯胺的物质的量比为3∶1;DBSA浓度为0.05mol/L时,CV测试的峰电流和电导率最大.     

Enhancement of polyaniline’s electrical conductivity by coagulation polymerization

An effective and simple method was developed to prepare highly conductive polyaniline by coagulation polymerization. Depending on the coagulation reaction between aniline salts and lauryl sulfonate (SDS), not only was the polymerization rate of aniline monomers greatly decreased but also the doping efficiency of hydrochloric acid was effectively increased. Low polymerization rate provided enough time for the conformation adjustment of polyaniline chains and the diffusion of doping agent. Meanwhile, the doping efficiency of hydrochloric acid on polyaniline chains was effectively increased due to its easy diffusion among many vacancies, which were generated when SDS separated in the process of polymerization. Therefore, the electrical conductivity of polyaniline prepared by coagulation polymerization was increased more than ten times than that of polyaniline, which was prepared by conventional methods. In addition, the important factors to influence the preparation, such as SDS concentration, hydrochloride acid (HCl) concentration, content of ammonium persulfate (APS), and polymerization time were also investigated. When the molar ratio (aniline:SDS:HCl :APS) was set to 1.69:0.46:15.38:1, the conductivity of polyaniline reached 24.39 S/cm.     

Effect of ionic liquid on polyaniline chemically synthesised under falling-pH conditions

This study investigates the effect of the ionic liquid 1-butyl-3-methyl imidazolium chloride ([bmim]Cl) on the morphological, structural, and electronic properties of polyaniline (PANI) products synthesised by the falling-pH method. Products were characterised by SEM, FT-IR, UVVIS, N₂-physisorption, and conductivity measurements. The [bmim]Cl addition strongly influenced the PANI morphology, specific surface area, porosity, and conductivity. Depending on the [bmim]Cl: ANI ratio and the synthesis pH, a wide range of PANI nanostructures could be prepared, with rod-like, and fibre-like elongated structures being the dominant morphology under most experimental conditions. Samples prepared in the presence of [bmim]Cl exhibit specific areas of ca 22–35 m² g^?1. The conductivity of the final products depends on the [bmim]Cl: ANI ratio. Temperature dependence of conductivity in the temperature range from 77 K to 300 K was also studied.     

Facile synthesis and intrinsic conductivity of novel pyrrole copolymer nanoparticles with inherent self-stability

Intrinsically self-stabilized nanoparticles of a copolymer from 4-sulfonic diphenylamine (SD) and pyrrole (PY) were facilely synthesized in HCl solution at 10 degrees C by a chemically oxidative polymerization. The critical reaction parameters such as SD/PY ratio, polymerization time, and oxidant species were studied to significantly optimize the polymerization yield, size, conductivity, and solubility of the final copolymer particles. The molecular structure, size, size distribution, and morphology of the particles were analyzed by IR spectroscopy, laser particle-size analysis (LPA), atomic force microscopy, and transmission electron microscopy (TEM). It was found that the polymerization yield of the SD/PY (50/50) copolymers increased dramatically in the initial 2 h of polymerization and then slowly enlarged in the subsequent 22 h. However, the copolymerization yield for the polymerization time of 24 h exhibited a nonlinear dependence on the SD/PY molar ratio, i.e., a maximum at 10/90 and a minimum at 80/20. The number-average diameter, Dn, of the copolymer particles strongly depended on the SD/PY ratio, decreasing rapidly from 6402 to 291 nm as the SD/PY molar ratio changed from 30/70 to 50/50, whereas the polydispersity index, PDI = Dw/Dn (where Dw is the weight-average diameter), surprisingly maintained very small values, decreasing slightly from 1.21 to 1.08. The SD/PY (80/20) copolymer particles prepared with (NH4)2S2O8 as the oxidant had the smallest size of ca. 10 nm by TEM and the lowest Dw/Dn value of 1.03 by LPA, whereas the copolymer particles prepared with FeCl3 as the oxidant exhibited the second smallest size of ca. 20 nm by TEM and the highest conductivity. The conductivity of the SD/PY (50/50) copolymers rose first and then decreased with increasing polymerization time from 10 min to 24 h, exhibiting a maximum (0.217 S/cm) at 12 h. It is of interest that the copolymer particles with SD/PY molar ratios in the range between 50/50 and 80/20 surprisingly exhibited the smallest size, the narrowest size distribution, and the highest conductivity at the same time. In particular, the copolymer nanoparticles exhibited high purity, clean surfaces, good self-stability, high conductivity, and strong chemoresistance that were very important to nanomaterial processibility and application. The obtained copolymers were partially soluble in concentrated H2SO4, demonstrating a new direction for synthesizing a soluble pyrrole copolymer.     

1H NMR study of the kinetics of substituted aniline polymerization. I. Homopolymerization of 2‐methoxyaniline

We studied the kinetics of the oxidative chemical homopolymerization of 2‐methoxyaniline (OMA) in aqueous acid solutions by monitoring OMA depletion with ¹H NMR spectroscopy. We used the same semiempirical kinetic model used for aniline (ANI) homopolymerization to evaluate the experimental data. The reaction kinetics of OMA homopolymerization was similar to that of ANI, although we obtained longer induction and propagation times for OMA. This was attributed to steric hindrance of the bulky methoxy substituent during the coupling reaction. Furthermore, it was suggested that a lower OMA polymerization rate could also be related to a lower concentration of nonprotonated OMA molecules in the reaction solution due to a higher pK_a value for OMA than for ANI. This may also explain the lower OMA end conversion (90%) compared with that of ANI (96%). The OMA end conversion was not influenced substantially by reaction conditions; it was lower than 90% only when high acid or low oxidant (oxidant‐deficient oxidant/OMA ratio) concentrations were applied. Because the oxidant took an active part in polymerization, it markedly influenced the polymerization rate, especially the initiation rate. The OMA initiation and propagation rates increased with increasing oxidant and initial monomer concentrations and with the reaction temperature, but there was no uniform trend in the correlation between the homopolymerization rate and acid concentration. The activation energies of the OMA initiation and propagation were 57 and 10 kJ/mol, respectively. © 2001 John Wiley & Sons, Inc. J Polym Sci Part A: Polym Chem 39: 2471–2481, 2001     

固相法合成苯胺与邻甲氧基苯胺共聚物及其性能

以苯胺和邻甲氧基苯胺为单体,甲磺酸为掺杂酸,用固相法合成了甲磺酸掺杂苯胺与邻甲氧基苯胺共聚物。 通过红外光谱、紫外可见吸收光谱、X射线衍射、透射电子显微镜、循环伏安和电导率等对共聚物进行了结构表征和性能测试。 结果表明,不同摩尔比的苯胺与邻甲氧基苯胺共聚物处于中间氧化态,随邻甲氧基苯胺含量的增大,共聚物的掺杂率降低。 共聚物具有较高的结晶性和纤维状形貌,当苯胺与邻甲氧基苯胺摩尔比为1∶1时,具有较高的电化学活性,其导电率为1.65 S/cm。     

Optimization of polymerization conditions of furan with aniline for variable conducting polymers

A high-throughput multiparameter optimization of chemical oxidative polymerization conditions has been developed for a facile synthesis of furan homopolymers and furan/aniline copolymers using a combinatorial method. The polymerization yield, molecular structure, and properties of the polymers would be optimized against typical polymerization parameters, including oxidant species, medium species, temperature, oxidant/monomer ratio, monomer concentration, dopant concentration, and furan/aniline comonomer ratio. The electrical conductivity, lead ion adsorptivity, chemical resistance, and thermal behavior of the polymers were also elaborated. It is found that only a combination of FeCl(3) and nitromethane as oxidant and medium, respectively, is appropriate for the furan homopolymerization. The homopolymerization yield increases consistently with an increase in the monomer concentration from 0.05 to 0.2 M and the FeCl(3)/furan molar ratio from 0.25 to 1.25. Although the as-prepared polyfuran exhibits very low conductivity, down to 10(-11) S cm(-1), the HCl- and HClO(4)-doped polyfurans possess much higher conductivities of 9.2 x 10(-8) and 2.38 x 10(-5) S cm(-1), respectively. In addition, the conductivity of the furan/aniline copolymer rises steadily with increasing aniline content, although the copolymerization yield shows a minimum at the furan/aniline molar ratio of 60/40, which is evidence of the occurrence of a real copolymerization between the furan and aniline monomers. The difficulty of synthesizing conducting polyfuran could be overcome to some extent by the polymerization in an appropriate condition optimized in this study. Particularly, the difficulty of synthesizing poly(furan-co-aniline) having much higher conductivity than the polyfuran would be largely conquered by chemical oxidative copolymerization of furan with aniline.     

Synergistical assembly of multiwalled carbon nanotubes/polyaniline network for dye‐sensitized solar cells

In this study, an aniline (ANI) solution containing well‐dispersed multiwall carbon nanotubes (CNTs) has been prepared. With an aim of improving the dispersability of CNTs in ANI monomer, we synthesize CNTs/ANI complexes using a reflux technique which can be electrochemically polymerized to form well‐dispersed CNTs/polyaniline (PANI) films. The refluxed CNTs/ANI solution can be used to prepare high porous CNTs/PANI network via an electrochemical polymerization for applying as counter electrodes in dye‐sensitized solar cells. Compared with the pristine PANI, the multiwalled CNTs/PANI network shows more porous morphology and higher electrocatalytic activity, resulting in the acceleration of the reaction (triiodide (I^3?) to iodide (I^?)) of the redox electrolyte. The enhancement of the electrocatalytic activity is attributed to the interactions between multiwalled CNTs and PANI, promoting the quinoid ring structure and thus enhancing the conductivity of the polymer chains. The device, assembled with multiwalled CNTs/PANI network as counter electrodes, delivers 7.67% power conversion efficiency, which is comparable to 7.43% of that with Pt. Copyright © 2014 John Wiley & Sons, Ltd.     

新型聚苯并咪唑树脂的微波合成及质子交换膜的性能

采用微波合成法, 调整己二酸和2,6-吡啶二甲酸2种二酸单体的配比, 使其与联苯四胺进行三元共聚, 制备出一系列新型含脂肪链结构的聚苯并咪唑(PBI)类质子交换膜, 并用红外光谱、 热重分析进行了表征, 对膜的吸水率、 溶胀率、 质子传导率、 机械强度及抗氧化性能等进行了测试. 当己二酸与2,6-吡啶二甲酸的摩尔比为3: 2时, 所制备的PBI-C₂膜掺杂磷酸后在160℃下的质子传导率可达30 mS/cm, 拉伸强度在常温下可达77.54 MPa, 断裂伸长率为39.25%, 最大储能模量为9.0623 MPa, 最大损耗模量为8.36 MPa, 玻璃化转变温度为360℃, 芬顿试验192 h后膜的降解率仅为0.21%, 表明PBI-C₂膜在高温质子交换膜燃料电池中具有较好的应用前景.     

APS/NaClO 复合氧化剂对乳液法合成聚苯胺的微观形貌及其电化学性能的影响

采用乳液法, 以过硫酸铵(APS)和次氯酸钠(NaClO)为复合氧化剂合成导电聚苯胺(PANI). 考察了NaClO 的加入与否对PANI 微观形貌与电化学性能(循环伏安和电导率)的影响, 以及APS、乳化剂十二烷基苯磺酸钠(SDBS)和NaClO的用量对PANI 电化学性能的影响. 结果表明: NaClO 的加入对PANI 的微观取向结构具有重要的影响. 与采用单一APS 合成的PANI 相比, 复合氧化剂合成的PANI 具有较高的循环伏安峰电流以及更加优异的电导率(约为前者的2.6倍). 当苯胺(An)与APS 的物质的量比(n_An:n_APS )为8:7, An 与SDBS 的物质的量比(n_An:n_SDBS )为10:4, NaClO 用量为5%(质量分数)时, PANI 的各项性能指标达到最好; 紫外可见光谱和红外光谱的表征结果表明, 采用复合氧化剂并未对PANI 的分子结构产生明显的影响.     

超疏水导电聚苯胺的界面聚合

采用界面聚合和无模板法相结合的方法, 以具有疏水链的全氟癸二酸(PFSEA)为掺杂剂, 通过调节苯胺单体和FeCl₃氧化剂的浓度实现了聚苯胺三维微/纳米结构形貌和尺寸的可控制备. 扫描电子显微镜测量结果显示, 聚苯胺是由一维纳米纤维自组装形成的三维微球结构; 红外吸收光谱和紫外-可见吸收光谱结果表明, 聚苯胺微球为掺杂态. 室温下, 该微/纳米结构聚苯胺微球的电导率为 9.6×10^-3 S/cm, 表面水接触角为161.4°, 表现出半导体特性和超疏水性.     

Kinetic studies on the syndiotactic propylene polymerization catalyzed over iPr(Cp)(Flu)ZrCl2

Kinetic studies on the syndiospecific polymerizations of propylene with iPr(Cp)(Flu)ZrCl₂/methylaluminoxane (MAO) were performed at 20, 40 and 70 °C and at 5 atm with various Al/Zr molar ratios. The average polymerization activity for 60 min decreased, and the time to reach a maximum activity (t_max) decreased as Al/Zr molar ratio increased. However, at Al/Zr molar ratio of 10,000, catalytic activity decreased rapidly and became the smallest among any other Al/Zr molar ratios after 20 min of polymerization. At higher Al/Zr molar ratio, methylation and cationization progress rapidly, but its polymerization rate decayed quickly due to strong interaction between MAO and metallocene, resulting in less active species. Regardless of change in polymerization temperature, t_max was maintained around 15 min. Stereoregularity was strongly dependent on the polymerization temperature, and active site isomerization was dominant source for stereoirregularity, and it was strongly influenced by polymerization temperature.     

沉淀聚合制备磺酸掺杂的聚苯胺

以二丁基萘磺酸(DBNSA)或十二烷基苯磺酸(DBSA)为有机酸,水为主要反应介质的条件下进行沉淀聚合直接制备有机酸掺杂的聚苯胺(PAn).讨论了酸度、温度和氧化剂用量等反应条件对产物的影响。2L规模扩大实验的产率约为75%～80%,所得PAn具有高电导率(3.0S·cm^-1),并易溶于普通有机溶剂。其中PAn-DBNSA在各方面较具优势。     

Polymerization of aniline in the interlayer space of molybdenum trioxide and its electrochemical properties

Molybdenum trioxide/polyaniline (MoO₃/PANI) composite was prepared first by ion-exchange reaction between aniline (ANI) and dodecylamine (DDA) which was intercalated precursor, and then was formed under the polymerization of ANI within the interlayer space of MoO₃ at 120 °C for 3 d in air. According to powder X-ray diffraction, scanning electron microscopy, thermogravimetric analysis, infrared spectroscopy and electrochemical testing, MoO₃/PANI composite has layered structure, and its interlayer spacing is 1.127 nm. Moreover, it has high thermal stability with the compound and completes its weight loss at 751.9 °C. Electrochemical investigation shows that MoO₃ is the major active substance in the MoO₃/PANI electrode, and MoO₃/PANI electrode demonstrates better conductivity and electrochemical activity than pure MoO₃ electrode, attributed to the promotion of Li⁺ and/or electron transport. In addition, the alternating current impedance proves that if the resistance of MoO₃/PANI electrode reduces apparently, the electrochemical activity will increase correspondingly, the same as the relationship between the ohmic resistance and the electrical conductivity.     

A new route to obtain PVDF/PANI conducting blends

Electrically conductive poly(vinylidene fluoride)(PVDF) - polyaniline blends of different composition were synthesized by chemical polymerization of aniline in a mixture of PVDF and dimethylformamide (DMF) and studied by electrical conductivity measurement, UV-Vis-NIR and FTIR spectroscopy. The samples were obtained as flexible films by pressing the powder at 180 °C for 5 min. The electrical conductivity showed a great dependence on the syntheses parameters. The higher value of the electrical conductivity was obtained for the oxidant/aniline molar ratio equal to 1 and p-toluenesulfonic acid-TSA/aniline ratio between 3 and 6. UV-Vis-NIR and FTIR spectra of the blend are similar to the doped PANI, indicating that the PANI is responsible for the high electrical conductivity of the blend. The electrical conductivity of blend proved to be stable as a function of temperature decreasing about one order at temperature of 100 °C. The route used to obtain the polymer blend showed to be a suitable alternative in order to obtain PVDF/PANI-TSA blends with high electrical conductivity.