单极脉冲电合成聚苯胺膜及其超级电容性能

采用单极脉冲电化学聚合方法在铂基体表面制备了具有三维网络结构的聚苯胺(PANI)纳米纤维膜。采用傅里叶变换红外(FT-IR)光谱和扫描电镜(SEM)分析比较了脉冲聚合和循环伏安聚合膜的组成和形貌,在0.5mol·L-1的硫酸溶液中通过恒电流充放电和电化学阻抗(EIS)等考察了聚合膜的电化学容量性能。研究表明,固定脉冲电压1.0V、苯胺单体浓度0.2mol·L-1时控制单极脉冲频率1.25s-1、占空比50%可获得高达699F·g-1比电容的纳米纤维结构PANI膜;聚合膜呈现均匀的三维有序网络状分布,其离子交换容量、循环稳定性及超级电容性能远高于循环伏安法聚合的PANI膜。     

掺水量对聚吡咯高分子膜电化学性能的影响

在0.1 mol/L吡咯+0.2 mol/L Na Cl O4的乙腈溶液中加入不同含量[0,3%,6%,9%(体积分数)]的水,采用循环伏安法制备了聚吡咯(PPy)高分子膜。利用扫描电子显微镜(SEM)对其表面形貌进行了观察,利用恒电流充放电曲线研究了其电化学性能。比较了不同电流密度下不锈钢/聚吡咯(SS/PPy)比电容和能量密度,当电流密度由1 m A/cm2增大到5 m A/cm2时,PPy(6%)电极的比电容下降幅度最小,下降了21.6%。     

掺水量对聚吡咯高分子膜电化学性能的影响

在0.1 mol/L吡咯+0.2 mol/L Na Cl O4的乙腈溶液中加入不同含量[0,3%,6%,9%(体积分数)]的水,采用循环伏安法制备了聚吡咯(PPy)高分子膜。利用扫描电子显微镜(SEM)对其表面形貌进行了观察,利用恒电流充放电曲线研究了其电化学性能。比较了不同电流密度下不锈钢/聚吡咯(SS/PPy)比电容和能量密度,当电流密度由1 m A/cm2增大到5 m A/cm2时,PPy(6%)电极的比电容下降幅度最小,下降了21.6%。     

MXene/PPy@TOCNF复合薄膜的制备及其电化学性能

利用聚吡咯(PPy)在纤维素纳米纤维(TOCNFs)表面原位聚合并结合MXene在真空过滤下制备MXene/PPy@TOCNF(MPT)混合膜。通过透射电子显微镜(TEM)、扫描电子显微镜(SEM)、X射线粉末衍射仪(XRD)等分析了(MPT)混合膜的结构与形貌,利用电化学工作站等探究了聚吡咯@纤维素纳米纤维(PPy@TOCNF)的含量对于MXene薄膜的电化学性能的影响。结果表明：PPy@TOCNF的加入会提高混合膜的电化学性能,在1 A·g^-1的电流密度下,MPT-20%薄膜比电容为415.6 F·g^-1,远高于MXene(284.5 F·g^-1)。     

CNT/PAn膜电极的电化学制备及电容性能研究

在含有0.2 mol·L-1苯胺的0.5 mol·L-1硫酸溶液中,采用循环伏安法,以50 mV·s-1的扫描速度,在-0.1~0.9 V的范围内实现了苯胺在碳纳米管修饰的金属钛电极上的电化学聚合,并用循环伏安(CV)法和电化学交流阻抗谱(EIS)对制备的碳纳米管/聚苯胺(CNT/PAn)膜电极的电化学性质进行了表征,同时进一步对该电极的充放电性能进行了研究。实验结果表明此条件下得到的PAn膜电极具有良好的导电性,同时具有疏松、多孔的网络结构,充放电测试研究表明,在电极基体上修饰CNT,不但可以增强PAn的导电性,同时可以使PAn的电容性能得到明显提高。     

功能单体对无皂苯胺/硅丙共聚乳胶膜防腐蚀性能的影响

以乙烯基三甲氧基硅烷(VTMS)为功能单体对丙烯酸酯乳液进行改性,得到有机硅改性丙烯酸酯乳液──硅丙乳液(SiAc);然后通过无皂乳液聚合法,以过氧化氢为氧化剂,引入苯胺(Ani),合成了无皂苯胺/硅丙(Ani/SiAc)共聚乳液。通过傅里叶变换红外光谱(FT-IR)、透射电子显微镜(TEM)等方法表征了Ani/SiAc共聚乳胶粒子的结构与形貌。借助动电位极化曲线和电化学阻抗谱(EIS)测量,考察了Ani/SiAc共聚乳胶涂层对Q235钢的防腐蚀性能,讨论了甲基丙烯酸(MAA)和VTMS含量对Ani/SiAc共聚乳液的基本性能以及共聚乳胶膜防腐蚀性能的影响。结果表明,以质量分数均为5%的MAA和VTMS制备的共聚乳液性能最佳,其乳胶膜的水接触角达到95.3°,电化学阻抗值达到2.58×10⁸Ω·cm²,腐蚀电流密度仅为3.89×10^-10 A/cm²。     

三维Y(OH)3@Ni(OH)2/CC复合材料的制备及其作为柔性超级电容器电极性能的研究

以碳布(CC)为基底，采用化学沉积、恒电位极化及电化学沉积法制备出Ni(OH)₂/CC复合材料和Y(OH)₃@Ni(OH)₂碳纤维复合材料(Y(OH)₃@Ni(OH)₂/CC)。以X射线粉末衍射(XRD)、扫描电子显微镜(SEM)等测试研究样品的结构、表面形貌和化学组成；利用电化学工作站的循环伏安(CV)、交流阻抗(EIS)等技术对样品的电化学性能进行研究。实验结果表明，该复合材料经恒电流50 mA/cm²充放电测试，其面积比电容为1 017 mF/cm²,CV循环1 000圈其面积比电容相对于初始面积比电容的保持率为167%。     

循环伏安法制备聚苯胺/活性炭超级电容器膜电极

采用电化学循环伏安法,在柔性石墨纸基底材料上合成了聚苯胺/活性炭(PANI/AC)复合薄膜。 通过SEM观察了不同扫描圈数下复合薄膜的表面形貌,通过循环伏安(CV)、交流阻抗(EIS)、恒流充放电等电化学测试方法,研究了聚苯胺/活性炭复合电极的电性能。由SEM图谱可知,不同扫描圈数下,聚苯胺/活性炭的形态也有所不同,电化学测试结果表明,以柔性石墨纸为基底材料,扫描圈数在3圈时,不仅比容量较高,达504 F·g^-1,而且循环稳定性较好,经2000次循环后,容量衰减仅为初始容量的14%。     

纳米颗粒组装三维Co3O4微米花材料制备及储锂性能研究

通过软模板法(表面活性剂十六烷基三甲基溴化铵,CTAB)结合后续空气气氛热处理制备出纳米颗粒组装三维Co₃O₄微米花负极材料。研究中采用X射线衍射分析(XRD)、场发射扫描电子显微镜(FESEM)、循环伏安测试(CV)、恒流充放电测试以及交流阻抗测试(EIS)对合成样品进行表征分析。研究结果显示,Co₃O₄微米花材料独特的结构优势赋予其优良的电化学性能,在100 mA·g^-1电流密度下电极具备约920 mA·h·g^-1的循环可逆比容量;在500 mA·g^-1电流密度下循环200次后的循环可逆比容量为757 mA·h·g^-1,容量几乎无衰减。大电流循环性能测试显示,所制备电极即使在2 A·g^-1电流密度下依旧具有476 mA·h·g^-1的循环可逆比容量。简易、有效且低成本化的高性能微米花结构过渡金属氧化物负极材料制备工艺将大大加速转换型电极材料的实际有效应用。     

含醌式结构的聚三苯胺衍生物锂电池正极材料制备及其电化学性能

有机聚合物材料因其特有的结构可设计性和优秀的氧化还原性能成为潜在的锂离子电池电极材料。本文合成了一种含有醌式结构的三苯胺衍生物功能单体(BDPAA),并通过氧化聚合法制备了聚[2,6- 双(二苯基氨基)- 9,10- 蒽醌]聚合物(PBDPAA)。作为锂电池正极材料,新型电极材料展现出提高的比容量和倍率性能(与聚三苯胺电极材料比较)。该电极材料首次放电比容量为 184.6mAh·g^-1;充放电循环稳定性能研究表明,电极材料比容量在初始几圈迅速衰减,5 圈之后基本稳定,50 圈循环后比容量保持在 93mAh·g^-1;倍率性能研究表明,在 20、50、100、200 和 500mA·g^-1 电流倍率下,电极材料的放电比容量分别为 119.3、104.9、92.1、90.3和 79.7mAh·g^-1。电化学阻抗测试得到 PBDPAA 材料具有比 PTPA 材料的电荷迁移阻抗,这有利于材料的电化学性能提高。     

High‐temperature oxidation of aniline to highly ordered polyaniline–sulfate salt with a nanofiber morphology and its use as electrode materials in symmetric supercapacitors

In this study, for the first time, aniline was oxidized by ammonium persulfate (APS) at higher temperatures without any protic acid, and APS acted as an oxidizing agent and a protonating agent. During the oxidation of aniline by APS, sulfuric acid formation occurred, and the sulfuric acid was incorporated into polyaniline (PANI) as a dopant. PANI–sulfate samples were characterized by IR spectroscopy, X‐ray diffraction, and scanning electron microscopy techniques. In this methodology, a highly ordered PANI–sulfate salt (H₂SO₄) with a nanofiber morphology was synthesized. Interestingly, a PANI base was also obtained with a highly ordered structure with an agglomerated netlike nanofiber morphology. PANI–H₂SO₄ was used as an electrode material in a symmetric supercapacitor cell. Electrochemical characterization, including cyclic voltammetry (CV), charge–discharge (CD), and impedance analysis, was carried out on the supercapacitor cells. In this study, the maximum specific capacitance obtained was found to be 273 F/g at 1 mV/s. Scan rate from cyclic voltammetry and 103 F/g at 1 mA discharge current from CD measurement. Impedance measurement was carried out at 0.6 V, and it showed a specific capacitance of 73.2 F/g. The value of the specific capacitance and energy and power densities for the PANI–H₂SO₄ system were calculated from CD studies at a 5‐mA discharge rate and were found to be 43 F/g, 9.3 W h/kg, and 500 W/kg, respectively, with 98–100% coulombic efficiency. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Growth Behavior of Poly(o-Anisidine-Co-Aniline) Deposition by Cyclic Voltammetry

Electrochemical copolymerization of o-anisidine (OA) with aniline (A) was carried out in 1 M H₂SO₄ by cyclic voltammetry. Polymeric films were deposited by employing different conditions such as cycle number and mole ratio of comonomers. Electrochemical homopolymerization of o-anisidine with aniline were also done. A growth equation for copolymer deposition relating parameters of operation and charge associated for film deposition was obtained. Growth rate constant was determined.     

Preparation and electrochemical capacitance of poly(pyrrole‐co‐aniline)

The copolymer of pyrrole and aniline, poly(pyrrole‐co‐aniline), has been prepared by chemical oxidation of corresponding monomer mixtures with ammonium peroxysulfate. Techniques of FTIR, SEM‐EDS, and BET surface area measurement were used to characterize the structure and morphology of the copolymer. The electrochemical properties of the copolymer were investigated by cyclic voltammetry, galvanostatic charge‐discharge, and electrochemical impedance spectroscopy. The results indicated that poly(pyrrole‐co‐aniline) was about 100–300 nm in diameter and showed better electrochemical capacitive performance than polypyrrole and polyaniline. The specific capacitance of the copolymer electrode was 827 F/g at a current of 8 mA/cm² in 1 mol/L Na₂SO₄ electrolyte. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

A redox‐mediator‐doped gel polymer electrolyte applied in quasi‐solid‐state supercapacitors

Methylene blue (MB) redox mediator was introduced into polyvinyl alcohol/polyvinyl pyrrolidone (PVA/PVP) blend host to prepare a gel polymer electrolyte (PVA‐PVP‐H₂SO₄‐MB) for a quasi‐solid‐state supercapacitor. The electrochemical properties of the supercapacitor with the prepared gel polymer electrolyte were evaluated by cyclic voltammetry, galvanostatic charge–discharge, electrochemical impedance spectroscopy, and self‐discharge measurements. With the addition of MB mediator, the ionic conductivity of gel polymer electrolyte increased by 56% up to 36.3 mS·cm^?1, and the series resistance reduced, because of the more efficient ionic conduction and higher charge transfer rate, respectively. The electrode specific capacitance of the supercapacitor with PVA‐PVP‐H₂SO₄‐MB electrolyte is 328 F·g^?1, increasing by 164% compared to that of MB‐undoped system at the same current density of 1 A·g^?1. Meanwhile, the energy density of the supercapacitor increases from 3.2 to 10.3 Wh·kg^?1. The quasi‐solid‐state supercapacitor showed excellent cyclability over 2000 charge/discharge cycles. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 39784.     

Synthesis of copolymer of aniline and pyrrole by inverted emulsion polymerization method for supercapacitor

Copolymer of aniline and pyrrole was synthesized by inverted emulsion polymerization method by oxidizing aniline and pyrrole using benzoyl peroxide in presence of sodium laurylsulphate surfactant and p‐toluenesulphonic acid. Copolymer samples were characterized by infrared, X‐ray diffraction and scanning electron microscopic techniques and compared their properties with the corresponding homopolymers. The optimum reaction conditions for the preparation of copolymer with reasonably good yield (1.72 g) and conductivity (7.3 × 10^?2 S/cm) were established. The synthesis procedure was extended to prepare copolymer samples using various protonic acids. Electrochemical characterization such as cyclic voltammetry, charge‐discharge and impedance were carried out on symmetrical supercapacitor cell consists of poly(aniline‐co‐pyrrole)‐p‐toluenesulfonic acid salt, wherein, the copolymer salt was synthesized using equal amount of aniline and pyrrole monomers. The values of specific capacitance, energy and power densities for poly(aniline‐co‐pyrrole)‐p‐toluenesulfonic acid system (PANI‐PPy) were calculated from charge‐discharge studies and are found to be 21 F/g, 5.7 Wh/Kg and 100 W/Kg respectively. Impedance analysis showed specific capacitance value (57 F/g) at 0.01 Hz at 0.22 V. Among the copolymer salts, copolymer prepared with sulfuric acid showed higher capacitance (66 F/g). © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2010     

Polyaniline/MnO2 composite with high performance as supercapacitor electrode via pulse electrodeposition

A method of pulse electrodeposition was proposed to synthesize polyaniline (PANI)/MnO₂ composite in aniline, H₂SO₄, and MnSO₄ aqueous solution. The PANI/MnO₂ composite has rod‐like structure and MnO₂ particles are distributed on PANI uniformly. To evaluate the performance of the as‐prepared materials as supercapacitor electrodes, cyclic voltammetry, galvanostatic charge–discharge measurements, and electrochemical impedance spectroscopy were performed. The PANI/MnO₂ composite shows a higher specific capacitance (810 F g⁻¹) than pure PANI (662 F g⁻¹) at a current density of 0.5 A g⁻¹. The cycle life of the composite was also excellent. After 1,000 cycles, it maintained 86.3% of its initial capacitance. POLYM. COMPOS., 36:113–120, 2015. © 2014 Society of Plastics Engineers     

Synthesis of dipropylaniline from aniline and n-propanol

A systematic study has been made of the synthesis of dipropylaniline from aniline and n-propanol using H₂SO₄ and HCl as catalysts. With both catalysts, the optimum temperature, pressure, residence period, mole ratio of aniline to n-propanol and mole ratio of aniline to H⁺ (catalyst) for the synthesis are 245°C, 600 lb/in², 2 h, 1:3 and 1:0.305 respectively. Very high pressure has practically no influence on the reaction and it helps only to form undesirable tarry matter. The maximum conversions of aniline to dipropylaniline under these optimum conditions are 45.53 and 46.57% with H₂SO₄ and HCl respectively. The conversion of aniline to propylaniline is always found to be greater than conversion to dipropylaniline. At the optimum conditions for the synthesis of dipropylaniline, conversions of aniline to propylaniline are 47.75% with H₂SO₄ and 51.55% with HCl.     

Electrospun polyaniline nanofibers web electrodes for supercapacitors

Polyaniline nanofibers (PANI‐NFs) web are fabricated by electrospinning and used as electrode materials for supercapacitors. Field‐emission scanning electron microscope micrographs reveal nanofibers web were made up of high aspect ratio (>50) nanofibers of length ～30 μm and average diameter ～200 nm. Their electrochemical performance in aqueous (1M H₂SO₄ and Na₂SO₄) and organic (1M LiClO₄ in propylene carbonate) electrolytes is compared with PANI powder prepared by in situ chemical oxidative polymerization of aniline. The electrochemical properties of PANI‐NFs web and PANI powder are studied using cyclic voltammetry, galvanostatic charge/discharge, and electrochemical impedance spectroscopy. PANI‐NFs web show higher specific capacitance (～267 F g^?1) than chemically synthesized PANI powder (～208 F g^?1) in 1M H₂SO₄. Further, PANI‐NFs web demonstrated very stable and superior performance than its counterpart due to interconnected fibrous morphology facilitating the faster Faradic reaction toward electrolyte and delivered specific capacitance ～230 F g^?1 at 1000th cycle. Capacitance retention of PANI‐NFs web (86%) is higher than that observed for PANI powder (48%) indicating the feasibility of electro spun PANI‐NFs web as superior electrode materials for supercapacitors. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

Effect of electrolyte on the supercapacitive behaviour of copper oxide/reduced graphene oxide nanocomposite

Cupric oxide/reduced graphene oxide (CuO/rGO) nanocomposites were synthesized through a chemical reduction method using hydrazine hydrate as the reducing agent. The morphology, elemental composition, and bonding network of the CuO/rGOnanocomposites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS) and Raman spectroscopy respectively. The XRD results reveal lattice spacing and lattice strain from 3.371 to 3.428 Å and 1.05 × 10⁻³to 5.44 × 10⁻³ respectively, with the increasing ratio of rGO: CuO from 1:1 to 1:5. The cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS)and galvanostatic charge-discharge (GCD) studyofCuO/rGOas the electrode material showed excellent super-capacitive behavior in H₂SO₄ over Na₂SO₄ electrolytes. Moreover CuO/rGO nanocomposites exhibited better capacitance retention in H₂SO₄(75.69%) compared to Na₂SO₄(12.06%).     

Synthesis and properties of oxalic acid-doped polyaniline

Conductive polyaniline was synthesized in aqueous 1.0M oxalic acid containing 0.1 M aniline by electrochemical and chemical oxidation and characterized by conductivity, solubility, ultraviolet and infrared spectroscopy, and cyclic voltammetry. The solubility experiments showed that the solubility of oxalic acid-doped polyaniline in dimethylsulfoxide and dimethylformaide increased to a certain extent. The soluble part of the polyaniline was free from impurities such as quinones. Cyclic voltammetric studies in oxalic acid medium revealed that aniline exhibited a similar behaviour to that in H₂SO₄ and the polymerization rate was much slower than that in H₂SO₄.