聚吡咯／多壁碳纳米管的合成及电化学行为

在含有多壁碳纳米管(MWCNT)的十二烷基苯磺酸钠(SDBS)溶液中电化学氧化吡咯(Py)制得聚吡咯/多壁碳纳米管(PPy/MWCNT)导电复合膜。研究了聚合温度、电流密度、吡咯浓度对PPy/MWC-NT复合膜沉积量的影响,采用交流阻抗谱(EIS)法研究了该导电复合膜的电化学行为,并用扫描电子显微镜对其表面形貌进行了观察。实验结果表明,随着温度的降低、电流密度及吡咯浓度的增大,复合膜沉积量变大。与纯PPy膜相比,PPy/MWCNT复合膜有更好的电子传递行为,而复合膜表面更加粗糙、疏松。     

PPy/MWNTs/GO复合材料的制备与电化学性能研究

以吡咯为单体,多壁碳纳米管和氧化石墨烯为模板,过硫酸铵为氧化剂,采用原位化学聚合法制备了聚吡咯/多壁碳纳米管/氧化石墨烯(PPy/MWNTs/GO)复合材料.利用傅里叶变换红外光谱(FTIR)、X射线衍射谱(XRD)、扫描电镜(SEM)、循环伏安法(CV)和电化学交流阻抗谱(EIS)对制备复合材料的结构、微观形貌和电化学性能进行了研究,探讨了多壁碳纳米管/氧化石墨烯比例、吡咯用量对复合材料电容性能的影响.研究结果显示,PPy/MWNTs/GO复合材料具有较大的比电容和良好的循环稳定性,且具有较小的电荷转移电阻,接近于理想的超级电容器用电极材料.     

合成扫速对聚苯胺/碳纳米管材料电容量性能的影响

采用循环伏安法在不锈钢上电化学制备碳纳米管/聚苯胺(CNTs/PANI)复合材料,并研究了不同扫速下(10、20、50、100、200mV/s)碳纳米管/聚苯胺复合材料的电化学性能。研究结果表明,复合材料中由于CNTs自身的大比表面积和强的导电率改善了复合物微观结构和导电性能,并且使聚苯胺更易电沉积到CNTs的表面形成核-壳结构,从而增加聚苯胺与电解液的接触机会。并且在扫速为20mV/s时生成的聚苯胺/碳纳米管膜具有导电率高,比容量大的电容性能,在22A/m2的电流密度下充放电测试,测其单电极比容量高达397F/g,远高于纯聚苯胺的比容量205F/g。     

吡咯单体浓度对聚吡咯膜层的防腐蚀性能影响研究

采用恒电位电化学沉积法,以十二烷基苯磺酸钠(SDBS)为掺杂剂,通过调节吡咯单体浓度(0.05mol/L、0.10mol/L、0.15mol/L、0.20mol/L)在Q235钢表面制备出系列聚吡咯(PPy)膜层。红外光谱表征显示SDBS成功掺杂到PPy中;扫描电镜显示吡咯单体浓度为0.10mol/L时,得到的PPy颗粒尺寸最小,膜层最为致密;动电位极化曲线和电化学阻抗谱的测试研究了Q235钢表面系列PPy膜层的防腐蚀性能,确定了Py单体浓度为0.10mol/L时,PPy膜层的腐蚀电流I_corr和腐蚀速率CR最小,表现出优异的防腐蚀性能。     

MEMS超级电容器用聚吡咯/炭材料复合膜电极的制备及其性能

采用电化学沉积工艺,在MEMS超级电容器的三维结构集流体上制备出聚吡咯(PPy)、聚吡咯/碳纳米管(PPy/CNT)、聚吡咯/石墨烯(PPy/GR)三种类型的膜电极。采用SEM对三种膜电极进行形貌观察,采用循环伏安、交流阻抗、恒电流充放电和循环充放电研究三种膜电极的电化学电容性能。结果表明,复合电极的微观结构稳定,复合薄膜和集流体之间的结合力大;基于三种膜电极的MEMS超级电容器电容量依次增大,阻抗依次减小,放电电流为1 mA时,比电容分别达到7.0、8.0、8.3 mF/cm2,经过5 000次恒流充放电循环后,电容器的比电容分别保持了原来的72.9%、85.0%和89.2%。在PPy电极中引入CNT或GR后,MEMS超级电容器的电化学和膜电极结构稳定性可得到明显改善。     

电化学合成聚吡咯-二氧化钛复合膜及其防腐蚀性能

目前鲜见对电化学原位生成的聚吡咯(PPy)-二氧化钛复合膜的系统研究。采用循环伏安法,在316不锈钢表面原位生成聚吡咯-二氧化钛(PPy-TiO_2)复合材料。FT-IR分析表明,通过电化学法可以在不锈钢表面生成PPy-TiO_2复合膜。利用SEM分析了PPy膜层与PPy-TiO_2膜层表面形貌,分别将316不锈钢、316不锈钢/PPy、316不锈钢/PPy-TiO_2浸泡至3.5%(质量浓度)Na Cl水溶液中,采用开路电位-时间(EOCP-t)曲线、电化学阻抗谱(EIS)考察了不同浸泡时间下PPy膜层与PPy-TiO_2复合膜层对金属的防护效果。结果表明:生成的PPy-TiO_2膜层具有更加均一的表面状态;在浸泡初期(15 min)与浸泡60 min后,相对于PPy膜层,PPy-TiO_2膜层具有较高的膜层电阻与较低的膜层电容,PPy-TiO_2的防护效果优于PPy。     

利用微量碳纳米管与石墨烯协同包覆提高LiCoO2正极材料的性能

采用高温固相法制备钴酸锂(LiCoO2)正极材料,将碳纳米管(CNTs)、氧化石墨烯(GO)与LiCoO2超声分散,经喷雾干燥和高温还原后,氧化石墨烯被还原成石墨烯(GR),最终得到均匀分散的碳纳米管/石墨烯/钴酸锂(CNTs/GR/LiCoO2)复合正极材料.实验采用X射线衍射(XRD)、红外光谱(FTIR)、扫描电镜(SEM)、透射电镜(TEM)以及电化学测试等方法,对材料的结构、形貌和电化学性能进行表征.实验结果表明,碳纳米管与石墨烯交替分散在LiCoO2颗粒表面,形成三维分层纳米级导电网络,能有效防止复合材料的团聚,与纯LiCoO2、GR/LiCoO2、CNTs/LiCoO2相比,CNTs/GR/LiCoO2复合材料表现出更优异的电化学性能,在0.5C时放电比容量为171.28 mAh/g,循环100次后放电比容量为154.50 mAh/g,容量保持率为90.24％,5C大倍率下放电比容量达到143.60 mAh/g.     

聚[1-(4-三甲基硅基)苯基-2-苯乙炔]/碳纳米管杂化膜的渗透汽化性能

采用聚[1-(4-三甲基硅基)苯基-2-苯乙炔](PTMSDPA)为膜材料,与碳纳米管(CNT)杂化制备PTMSDPA/CNTs杂化膜,研究了碳纳米管含量对杂化膜的气体分离、渗透汽化性能的影响。结果表明,PTMSDPA与碳纳米管间π-π相互作用使得碳纳米管在聚合物基体中实现均匀分散。当碳纳米管质量分数为15%时,PTMSDPA/CNTs杂化膜的氧气渗透系数出现极大值(2880 Barrers),为PTMSDPA均质膜的2.4倍;操作温度为30℃时,渗透汽化分离丁醇质量分数为1.5%的丁醇/水溶液,PTMSDPA/CNTs杂化膜的渗透通量、丁醇/水分离系数也达到极大值,分别为114 g/(m~2·h)和69。溶胀吸附实验结果表明,PTMSDPA/CNTs杂化膜的丁醇/水渗透汽化性能主要来源于溶解选择性。     

等离子体诱导接枝聚合修饰碳纳米管及其环氧树脂复合材料

以马来酸酐(MAH)为有机单体,通过等离子体诱导接枝聚合法修饰碳纳米管(CNTs),借助红外光谱、扫描电镜分析手段,对所得表面为聚合物膜修饰碳纳米管(p-CNTs)进行表征。将上述p-CNTs应用于环氧树脂(EP)固化体系,制备出p-CNT/EP纳米复合材料,研究了其对EP性能的影响。结果表明:等离子体可诱导马来酸酐在CNTs表面接枝聚合成膜。利用包覆于CNTs表面的聚马来酸酐(PMAH)薄膜功能化修饰CNTs。合适含量的p-CNTs可显著提高环氧树脂的强度和韧性,使其高度强韧化。     

碳纳米管/聚酰亚胺复合材料的制备及其电化学性能研究

采用原位聚合法,以2,4-二氨基-6-氯嘧啶(DCP)、3,3’,4,4’-二苯甲酮四羧酸二酐(BTDA)和碳纳米管(CNTs)为原料,制备碳纳米管/聚酰亚胺(CNTs/PI)复合材料,并且对它们的分子结构、结晶性、微观形貌和电化学性能进行研究。结果表明,CNTs/PI复合材料属于半晶型材料,PI均匀地包覆在CNTs的表面。CNTs/PI复合材料具有较好的电化学氧化还原行为,随着CNTs含量的增加,复合材料的氧化电位逐渐向高电位移动,还原电位逐渐向低电位移动,这主要是由于CNTs的加入导致复合材料失电子能力减弱,得电子能力增强的结果。     

Surfactant-dependent macrophage response to polypyrrole-based coatings electrodeposited on Ti6Al7Nb alloy

In this study, polypyrrole (PPy) films were successfully synthesized on Ti6Al7Nb alloy by potentiostatic polymerization in the presence of poly(sodium 4-styrenesulfonate) (NaPSS), t-octylphenoxy polyethoxyethanol (Triton X-100) and N-dodecyl-β-D-maltoside (DM) surfactants. Atomic force microscopy (AFM) analysis of the PPy/surfactant composite films revealed a granular structure characterized by a lower surface roughness than un-modified PPy films. The results demonstrated that addition of surfactants, namely Triton X-100 and DM, can improve electrochemical film stability and corrosion resistance. Further, Triton X-100 enhanced the adhesive strength of PPy films to the substrate. The surfactant type also showed a great influence on the surface wettability, the highest hydrophilic character being observed in the case of PPy/PSS film. Few studies have been devoted to the elucidation of inflammatory cell response to PPy-based materials. Therefore, RAW 264.7 macrophages were cultured on PPy-surfactant films to determine whether they elicit a differential cell behavior in terms of cell adhesion, proliferation, cellular morphology and cytokine secretion. Our results highlight the dependence of macrophage response on the surfactants used in the pyrrole polymerization process and suggest that the immune response to biomaterials coated with PPy films might be controlled by the choice of surfactant molecules.     

Influence of dopant in the synthesis, characteristics and ammonia sensing behavior of processable polyaniline

Polyaniline (PANI) was synthesized by oxidative polymerization of aniline as well as aniline hydrochloride by ammonium persulfate in the presence of para-toluene sulfonic acid (PTSA). This helped in direct usage of the conducting PANI solution for film casting and use as a device for ammonia gas sensing. Viscosity change with applied shear rate was measured for both the polymers. Solid PANI powder was isolated from its tetrahydrofuran solution by using methanol as non-solvent. Thermogravimetric analysis investigated the thermal properties of the solid PANI salts. Elemental analysis of both PANI synthesized in presence of PTSA and PANI synthesized in presence of HCl and PTSA was investigated. A thin coherent film of both the conducting PANI were deposited on glass slides precoated with poly vinyl alcohol (PVA) crosslinked with maleic acid (MA) and was directly used in the sensor device. The morphology of the deposited films was analyzed by scanning electron micrograph. The films were further characterized by Attenuated total reflectance Fourier transformed infrared spectroscopy, ultra violet-visible spectroscopy and X-ray diffraction analyses. Finally, both the doped PANI films on MA crosslinked PVA coated glass slides were used to measure the conductivity and ammonia gas-sensing characteristics.     

利用氧等离子体预处理增强聚对苯二甲酸乙二醇酯/聚吡咯导电复合薄膜的界面粘附性

首先对聚对苯二甲酸乙二醇酯(PET)薄膜进行氧等离子体预处理,然后通过原位化学氧化聚合法使得吡咯单体在PET薄膜表面沉积聚合,制备了聚对苯二甲酸乙二醇酯/聚吡咯(PET-PPy)复合膜。通过原子力显微镜、X射线光电子能谱仪、ζ电位测试对经不同时长的氧等离子体预处理的PET薄膜进行表征;利用扫描电子显微镜、耐磨性实验和表面电阻测试对PET-PPy复合膜磨损前后的表面形貌和电阻进行分析与表征。结果表明,氧等离子体预处理显著增强了PET-PPy复合膜界面粘附性。氧等离子体预处理使PET薄膜表面粗糙度增大、电负性显著增强。特别地,当预处理时间为120s时,薄膜表面电负性明显增强,此时PET-PPy复合膜磨损后的电阻值变化最小,表明PET薄膜与PPy功能层界面粘附强度得到明显增强。     

Synthesis of polypyrrole and carbon nano-fiber composite for the electrode of electrochemical capacitors

Nano-thin polypyrrole (PPy) films were deposited on vapor grown carbon fibers (VGCF) by using an in situ chemical polymerization of the monomer in the presence of FeCl₃ oxidant. An ultrasonic cavitational stream was used during polymerization of pyrrole, to enable the deposition of uniformly nano-thin PPy films on the surface of VGCF. The PPy/VGCF composite was characterized by FTIR spectroscopy. Surface morphology of the polymer films was characterized by using scanning electron microscopy and scanning transmission electron microscopy. The capacitance of the composite electrodes was investigated with cyclic voltammetry. As results of this study, thinner layer of PPy in the composite electrode (< 10 nm) was effective to obtain fully reversible and very fast Faradaic reaction. Hence, most mass of the PPy could contribute to the pseudo-capacitive charge storage. This nano-thin PPy layer exhibited higher specific capacitance of ∼588 F g^− 1 at 30 mV s^− 1 and ∼545 F g^− 1 at 200 mV s^− 1 along with an excellent power capability.     

基于界面相互作用构建纳米纤维素-羧基化碳纳米管-石墨/聚吡咯柔性电极复合材料

以纳米纤维素(CNF)、羧基化碳纳米管(CNTs—COOH)、铅笔石墨(PGr)、聚吡咯(PPy)为原料,通过真空抽滤、涂覆、氧化聚合等方法,同时基于氢键界面相互作用的原理,制备出具有石墨层结构的CNF-CNTs—COOH-PGr/PPy柔性电极复合材料。结果表明,CNF-CNTs—COOH-PGr/PPy柔性电极复合材料在平直、折叠和拉伸时不会断裂,展现出较强的力学性能,其拉伸强度达到28.90 MPa。亲水性CNF与CNTs—COOH构筑的多孔结构增强了离子和电子的扩散路径。PGr的加入有效增加了CNF-CNTs—COOH-PGr/PPy柔性电极复合材料的导电路径,赋予其优良的导电性能。氧化聚合后得到的CNF-CNTs—COOH-PGr/PPy柔性电极复合材料的电导率达到5.403 S·cm?1。在1 mol·L?1 H₂SO₄溶液中,0.5 A·g?1电流密度下,CNF-CNTs—COOH-PGr/PPy柔性电极复合材料具有521 F·g?1的高比电容量,且经过1 500次充放电循环后,其电容保持率高达68%。基于柔性电极优良的力学性能、电化学性能和导电性能,CNF-CNTs—COOH-PGr/PPy柔性电极复合材料具备成为柔性储能器件电极材料的基本特性。      

Preparation, characterization and anion exchange properties of polypyrrole/carbon nanotube nanocomposites

In this study, polypyrrole (PPy) thin films were electrodeposited on carbon nanotube (CNT) backbones by applying a constant deposition potential in 0.1 M pyrrole solution with different electrolytes, such as NaCl, NaNO3, or NaClO4. The hybrid films were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy, and cyclic voltammetry. SEM images revealed the nanostructrure of PPy films generated on CNT surface. The electrochemical and anion exchange properties of the PPy-CNT composite films have been investigated. Nanostructured composite thin films of PPy-CNTs were studied by cyclic voltammetry between 0.4 and -0.8 V in aqueous solution to evaluate their cycling stability and capacity for electrically switched anion exchange. The presence of the CNT backbone greatly improved the anion exchange capacity and stability of the PPy-CNT composite film, which may be attributed to the high surface area of CNT matrix, nanostructure of the PPy film, and the interaction between CNTs and PPy.     

Highly flexible and bendable free-standing thin film polymer for battery application

Highly flexible and bendable free-standing polypyrrole (PPy) films were prepared using the electrochemical polymerization method. The paper-like films are soft, lightweight, mechanically robust, and highly electrically conductive. The morphologies and electrochemical behaviour of the free-standing pure PPy films were affected by the electrochemical polymerization conditions. The free-standing films show promise as cathodes for flexible and bendable batteries.     

Chemical in situ polymerization of polypyrrole on poly(methyl metacrylate) substrate

Combination of electrically and optically active organic materials in one fiber would enable to realize several interesting smart systems in a simple and cost effective manner. In this work the coating of plastic optical material-poly(methyl metacrylate)-was carried out by in situ chemical polymerization of polypyrrole (PPy). Two ways of chemical polymerization were compared: (a) using FeCl₃ and (b) using ammonium peroxydisulphate with p-toluene sulfonic acid. Both planar and fiber samples were prepared. The samples are characterized by their surface resistivity and surface morphology. The influence of polymerization conditions like temperature, time and reactant concentration on surface resistivity is discussed. Optical transmission properties of PPy films are presented. The ageing of samples was studied within 4 weeks time.     

绝缘基底上两步法聚合导电聚吡咯膜的研究

在绝缘性陶瓷基底上,运用先化学聚合、再以所得的聚吡咯(PPy)膜为电极进行电化学聚合的两步聚合法生成了电导率较高、活性高的PPy膜.SEM和电导率的测试结果表明电化学聚合过程中膜的厚度增加不明显,大部分电流基本上都用于化学聚合所得膜的修补和致密化,这可使膜的电导率提高10倍以上.FT-IR红外分析表明,所得的PPy膜并没有随聚合时间的延长而发生氧化,仍保持较高的化学活性.