单根聚苯胺纳米线导电性的研究

纳米线(管)的模板合成和导电原子力显微镜(C-AFM)结合是一种近期发展起来研究单根一维纳米结构及阵列导电性的有效方法. 本文利用C-AFM测量了阳极氧化铝(AAO)模板电化学合成制备的单根聚苯胺纳米线的电导率, 研究了直径、氧化还原态对单根聚苯胺纳米线电导率的影响. 从I－V曲线可以看到, 其导电性质与半导体类似，但又不同于半导体． 尚未观察到反向击穿现象，可能原因是, 在一定的反向偏压下的离子脱嵌使得它由部分氧化态（导电态）转变为还原态（绝缘态）；电导率随纳米线直径减小而线性地增加；以ClO₄^－离子掺杂的氧化态和还原态比部分氧化态的电导率低二个数量级.     

聚苯胺电致变色薄膜的红外发射特性研究

为实现聚苯胺电致变色薄膜红外发射率的大幅度调制,在柔性PET-ITO薄膜基底上恒电位沉积硫酸-磺基水杨酸共掺杂的聚苯胺薄膜.采用扫描电镜和傅立叶红外光谱仪表征了薄膜的形貌和结构,用红外比辐射率测试仪和紫外-可见分光光度计测量薄膜的红外发射率和可见光透过率.在优化电解液浓度配比的基础上,通过建立薄膜红外发射率与方块电阻之间的关系曲线(R-E曲线),深入探讨了影响聚苯胺红外发射特性的关键因素.研究结果表明,在薄膜中聚苯胺厚度和电导率的影响下,红外发射率和方块电阻之间遵循对数函数的变化特征.随着中间态发射率E0的增加,氧化态和还原态的红外发射率呈阶梯状上升,红外发射率调制幅度ΔE先增大后减小,在0.71处达到最大值.同时,红外发射率调节对薄膜的可见光电致变色性能无消极影响,可见光平均透过率之差可达43.8%.     

乳液聚合—萃取法制备掺杂态聚苯胺溶液

提出了一种“乳液聚合－萃取”法制备掺杂态聚苯胺溶液的方法。该方法不仅简化了制备步骤，而且减少了有机溶剂的用量从而有利于环境保护。ＳＥＭ，ＵＶ－Ｖｉｓ，ＦＴＩＲ和ＸＰＳ测量表明用该方法所得到的聚苯胺薄膜具有典型的掺杂态聚苯胺的结构特征，证实这种方法的有效性。     

盐酸掺杂聚苯胺的制备及性能研究

本文用溶液聚合法制备盐酸掺杂聚苯胺,测定了体系酸度对聚苯胺电导率的影响,及盐酸掺杂聚苯胺在不同条件下经过热处理后的电导率,采用TGA、XRD等方法,研究了热处理过程对聚苯胺结构的影响。结果表明,当热处理温度为90℃时,电导率高于初始值,当热处理温度高于100℃时,电导率开始下降,到达220℃时,电导率下降了约4个数量级。在氮气中聚苯胺电导率的衰减比空气中小,聚苯胺经热处理后在浓硫酸中的溶解性会明显降低。本文还探讨了去掺杂、氧化和化学交联等盐酸掺杂聚苯胺的热降解机理。     

溴掺杂聚苯胺的导电性能及机理研究

通过化学氧化法制备聚苯胺,对其进行溴和氢溴酸掺杂,聚苯胺(PANI)的电导率比掺杂前提高了11-13个数量级。采用红外光谱、热重分析、紫外可见光谱和X射线光电子能谱分析研究了溴和氢溴酸对PANI的掺杂作用,探讨了掺杂PANI的导电机理。研究表明,不同于氢溴酸对PANI的质子酸掺杂,溴掺杂过程中产生的溴负离子增加了PANI的载流子浓度并形成电子转移复合物,提高了聚苯胺的电导率。     

硼掺杂多晶金刚石薄膜电极的电化学特性

用循环伏安法和恒电位法研究了硼掺杂多晶金刚石薄膜电极（ＤＦＥ）的若干电化学特性。电极面积４×４ｍｍ＾２。在０．１ｍｏｌ／Ｌ ＫＣｌ，ＮａＮＯ３，ＮａＯＨ和ＫＨ２ＰＯ４＋Ｎａ２ＨＰＯ４（ｐＨ＝６．８６）电解质溶液中电势窗口均为－５００￣＋８００ｍＶ；而在０．１ｍｏｌ／Ｌ ＨＣｌ和Ｈ２ＳＯ４溶液中电势窗口为－２００￣＋１１００ｍＶ．Ｋ３Ｆｅ（ＣＮ）６的氧化峰电位为＋５００ｍＶ，与Ｐｔ电极测量相同；校正     

还原态卤代聚苯胺能带结构及掺杂导电机理的研究

用ＥＨＭＯ－ＣＯ方法研究了卤代聚苯胺的能带结构及其掺杂导电机理，结果表明，在掺杂态卤代聚苯胺中形成单极化子晶格；取代主要通过改变带宽影响电导率，由掺杂而大幅度地提高了电导率是因为大大缩小了带隙，并进一步证实了外层ｄ轨道的成键作用。     

高能球磨法固相掺杂制备樟脑磺酸掺杂聚苯胺

通过高能球磨方法引发樟脑磺酸(CSA)对本征态聚苯胺(PANI)的固相掺杂反应, 制备了樟脑磺酸掺杂聚苯胺(PANI-CSA)粉末. 采用SEM, XRD, FT-IR等分析方法对所得的PANI-CSA进行了形貌和结构表征, 采用四点探针法对电导率进行了测定. FT-IR图谱的变化反映了聚苯胺的质子化过程, 而XRD谱图表明, 聚苯胺分子链在外力诱导下形成了有利于电荷传导的取向排列. 系统地研究了球磨时间对掺杂率和电导率的影响规律. 结果表明, 固相掺杂具有较高的掺杂速率, 其电导率和掺杂率均随球磨时间先增大后减小, 其最高电导率可达到3.25 S/cm, 对应掺杂率为0.31.     

复合酸掺杂导电聚苯胺的性能研究

以苯胺为单体、过硫酸胺为氧化剂,由化学氧化聚合法在磺基水杨酸和硫酸的复合酸的水溶液中合成导电聚苯胺,并通过压片法、激光粒度分析、扫描电镜、差热分析及红外光谱对掺杂态聚苯胺的电导率、表面形貌及结构进行了研究.结果表明,复合酸掺杂聚苯胺的热稳定性比仅用硫酸掺杂聚苯胺的有了很大的提高;所得导电聚苯胺的粒度分布比较均匀(平均粒径约15.4μm);复合酸掺杂使聚苯胺分子链上的电荷呈离域化,掺杂程度提高.     

掺杂质子酸的类型对聚苯胺结构和电导率的影响

采用化学氧化聚合法以苯胺为单体，过硫酸铵为氧化剂，在不同质子酸的水溶液中合成聚苯胺，考察质子酸对聚苯胺电性能影响，并通过傅立叶红外吸收光谱（FTIR）和紫外可见光吸收光谱（UV－vis)研究聚苯胺掺杂前后结构的变化。结果表明，龙质子酸掺杂后聚 胺具有导电性是因为其分子链上电荷离城形成了共轭结构，具有不同质子酸中生成的聚苯胺氧化程度不同；分子链共轭程度与掺杂酸对阴离子大小有关，掺杂质子酸对阴离子越大，聚苯胺分子链共轭程度越大，电导率也就越高。     

聚乙炔的离子注入法掺杂

<正> 离子注入是一种物理摻杂方法,在半导体器件的制备中已得到广泛的应用,它与常规的化学、电化学或热扩散掺杂相比具有一些特点:可以通过质量分析器选取单一的注入离子,故掺杂杂质的纯度高;根据注入离子的剂量和能量,精确控制到掺人杂质的数量和深度等等。近年来,采用离子注入技术进行掺杂,改变聚合物或其它绝缘材料表面性质的研究已逐步引起重视真视。     

Ion implantation doping and electrical properties of high-temperature ladder polymers

We report the first ion implantation doping studies on high-temperature ladder polymers and show that insulting films of the benzimidazobenzophenanthroline-type ladder polymer (BBL) can be doped by boron, argon, and krypton implantation to conductivities as high as 224 S/cm at a dose of 4.0 × 10¹⁶/cm² while retaining the excellent mechanical properties of the pristine films. Effects of dose (ions/cm²) and beam current density (microamps/cm²) on electrical conductivity at fixed ion energies are reported. The temperature dependence of the conductivity indicates that the implanted ladder polymer films are semiconductors. Spatially selective implantation, creating regions of conducting lines in an insulating matrix, which suggests microelectronic device applications of the ladder polymers, is demonstrated.     

N+离子注入聚对苯乙炔衍生物的非线性光学性能

以对甲氧基苯酚和溴代异戊烷为原料,用脱氯化氢反应制备可溶性聚[2-甲氧基-5-(3'-甲基)丁氧基]对苯乙炔(MMB-PPV),通过核磁氢谱(1HNMR)和红外光谱(FTIR)对产物分子的结构进行表征.用能量为15keV、剂量为3.8×1015～9.6×1016ions/cm2的氮正离子(N+)对MMB-PPV薄膜进行注入改性.紫外-可见吸收光谱(UV-Vis)显示,注入离子在MMB-PPV薄膜内部引入杂质能级,破坏了分子的共轭结构.随着注入剂量增加,吸收边逐渐向长波方向移动,且分子激发态和基态间的光学带隙由2.12eV减小至1.81eV.用简并四波混频(DFWM)技术研究了离子注入MMB-PPV薄膜的三阶非线性光学性能.结果表明,未注入薄膜的三阶非线性极化率(χ(3))值为7.1×10-10esu,随着注入剂量的增加,χ(3)值逐渐增大,当注入剂量达到3.8×1016ions/cm2时,χ(3)值提高到9.3×10-9esu,继续增加注入剂量,χ(3)值开始下降,当注入剂量为9.6×1016ions/cm2时,χ(3)值降低到1.5×10-10esu.对离子注入MMB-PPV薄膜χ(3)值变化的机理进行了探讨.     

聚苯胺嵌入氧化石墨复合物的合成及表征

近年来,聚苯胺类导电高分子嵌入无机片层化合物的报道日趋增加.这些材料中,由于无机/有机的纳米复合,一方面使无机材料的传输性能,如导电性等有极大改善,同时也使该类材料的电化学性能有极大的提高.因此对这类纳米复合材料的研究越来越为广大科研工作者所重视[1～8].作为一种二维的层状化合物,氧化石墨层间大量极性基团的存在虽然赋予了氧化石墨丰富的嵌入化学(Ｉｎｔｅｒｃａｌａｔｅｃｈｅｍｉｓｔｒｙ)[7～11],但在一定程度上也破坏了原石墨的晶体结构,致使其导电率大大降低(接近非导体).因此,如何以常用的纳米复合技术实现氧化石墨(ＧＯ…     

Electrochemistry of conductive polymers 36. pH dependence of polyaniline conductivities studied by current-sensing atomic force microscopy

We demonstrate from our current-sensing atomic force microscopic studies that both electrical and topographical properties of electrochemically prepared polyaniline (PAn) films are affected by their preparation conditions. The electrical properties of the fully doped PAn films prepared in 0.30 M nitric acid with its pH and ionic strength adjusted to 0.50 can be described as a conductor with an average conductivity of 49 (+/-13) S/cm with primarily a compact structure resulting from a relatively small growth rate. The doped PAn films prepared at pH 5.0, for example, have compact structures with large grains and lightly doped semiconducting properties with an average conductivity of about 1.54 (+/-0.09) x 10(-4) S/cm. From these data, we conclude that the degree of protonation of the monomers and the main reactions taking place during an early stage of the polymerization reaction are important factors determining the chemical structures as well as their conductivities and morphologies of the PAn films.     

Thermal properties of poly(anthranilic acid) (PANA) and humidity-sensitive composites derived from heat-treated PANA and poly(vinyl alcohol)

Thermal conversion of poly(anthranilic acid) (PANA) to polyaniline (PAn) has been studied by means of thermogravimetric/mass (TG/MS) and Fourier transform infrared (FTIR) spectroscopy. The electrical conductivity of the chemically prepared PANA was 3.5 × 10⁻² S/cm, which is caused by the self-doping of the polaronic nitrogen atom interacting with the ionized carboxyl group ( COO⁻). The heat-treated PANA can be assumed to be identical to an emeraldine base of PAn. The pyrolysis of PANA proceeded through the decarboxylation at two stages from carboxyl ( COOH) and ionized carboxyl groups, which occurred at about 170 and 230 °C, respectively. PANA–SA, which was prepared by treating PANA at 250 °C and then doping with an external protonic acid at room temperature, showed a considerably high conductivity (6.2 S/cm). The composite consisting of PANA–SA and poly(vinyl alcohol) was very sensitive to the environmental humidity. The logarithm of electrical conductivity of this composite was proportional to the relative humidity covering more than five orders of magnitude, and the change in conductivity extended from 4.2 × 10⁻⁵ to 10 S/cm upon the humidity variation from 14 to 91%. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 4458–4465, 1999     

Dielectric properties and surface morphology of swift heavy ion beam irradiated polycarbonate films

Swift heavy ion beam irradiation induces modification in the dielectric properties and surface morphologies of polycarbonate (PC) films. The PC films were irradiated by 55 MeV energy of C⁵⁺ beam at various ions fluences ranging from 1 × 10¹¹ to 1 × 10¹³ ions cm^?2. The dielectric properties (i.e., dielectric constant, dielectric loss, and AC conductivity) and surface morphologies of pristine and SHI beam irradiated PC films were investigated by dielectric measurements, atomic force microscopy (AFM), and optical microscopy. The dielectric measurements show that the dielectric constant, dielectric loss, and AC conductivity increase with ion fluences and temperature, however, the dielectric constant and AC conductivity decrease while dielectric loss increases with frequency. AFM shows the increase in average roughness values with ion fluences. The change of color in PC films has been observed from colorless to yellowish and then dark brown with increases of ion fluence by using optical microscopy.     

Transport property of polyaniline and its molecular weight dependence

Ｔｈｅｅｌｅｃｔｒｉｃａｌｃｏｎｄｕｃｔｉｖｉｔｙ(σ)ｏｆｐｏｌｙａｎｉｌｉｎｅ(ＰＡｎ)ｄｏｐｅｄｗｉｔｈｉｎｏｒｇａｎｉｃｐｒｏｔｏｎｉｃａｃｉｄｓｉｓａｂｏｕｔ10Ｓ/ｃｍａｎｄσ(Ｔ)∝ｅｘｐ[-(Ｔ0/Ｔ)1/2].Ｉｔｍｅａｎｓｔｈａｔσｉｎｃｒｅａｓｅｓｗｉｔｈｉｎｃｒｅａｓｉｎｇｔｅｍｐｅｒａｔｕｒｅａｎｄｔｈｅｔｒａｎｓｐｏｒｔｐｒｏｐｅｒｔｙｉｓｉｎａｃｃｏｒｄａｎｃｅｗｉｔｈｔｈｅｖａｒｉａｂｌｅｒａｎｇｅｈｏｐｐｉｎｇ(ＶＲＨ)ｍｏｄｅｌ[1].Ａｆｔｅｒｓｔｒｅｔｃｈｉｎｇ,ｔｈｅＨＣｌｄｏｐ…     

Conductive polymers as a new type of thermoelectric material

Thermoelectric properties were investigated for the films of electrically conductive doped polyanilines. The thermoelectric performance, evaluated by thermoelectric figure-of-merit (ZT = T (S² σ) / κ), of various protonic acid-doped polyaniline bulk films was found to depend on the electrical conductivity σ of the film. Thus, the higher the electrical conductivity, the higher the figure-of-merit is, because the thermal conductivity κ of polyaniline films does not depend on the electrical conductivity. Among the conductive bulk films of polyaniline, the highest figure-of-merit (ZT = 1 × 10⁻⁴) was observed for (±)-10-camphorsulfonic acid (CSA)-doped polyaniline in an emeraldine form (σ - 188 S cm⁻¹) at room temperature. The multilayered film, composed of electrically insulating emeraldine base layers and electrically conducting CSA-doped emeraldine salt layers, exhibited 6 times higher ZT at 300 K than that of a bulk film of CAS-doped polyaniline, showing the highest ZT value of 1.1 × 10⁻² at 423 K. Stretching of the CAS-doped polyaniline film also increased the figure-of-merit of doped polyaniline films along the direction of the stretching.     

Conductive and optical properties of PPV modified by N+ ion implantation

In this article, a soluble poly[2‐methoxy‐5‐(3′‐methyl)butoxy]‐p‐phenylene vinylene (MMB‐PPV) was synthesized by dehydrochlorination reaction and the MMB‐PPV film was implanted by nitrogen ions (N⁺) with the ion dose and energy in the range of 3.8 × 10¹⁵ to 9.6 × 10¹⁶ ions/cm² and 15–35 keV, respectively. The surface conductivity, optical absorption, optical band gap (E_g) of modified MMB‐PPV film were studied, and the third‐order nonlinear optical susceptibility (χ⁽³⁾) as well as its environmental stability of modified MMB‐PPV film were also measured by degenerate four‐wave mixing system. The results showed that the surface conductivity of MMB‐PPV film was up to 3.2 × 10^?2 S when ion implantation was performed with the energy of 35 keV at an ion dose of 9.6 × 10¹⁶ ions/cm², which was seven order of magnitude higher than that of the pristine film. UV‐Vis absorption spectra demonstrated that the optical absorption of MMB‐PPV film was enhanced gradually in the visible region followed by a red shift of optical absorption threshold and the E_g value was reduced from 2.12 eV to 1.59 eV with the increase of ion dose and energy. The maximum χ⁽³⁾ value of 2.45 × 10^?8 esu for modified MMB‐PPV film was obtained with the ion energy of 20 keV at an ion dose of 3.8 × 10¹⁶ ions/cm², which was almost 33 times larger than that for pristine film. In comparison to the reduction of 17% in the χ⁽³⁾ value of pristine MMB‐PPV film, the maximum χ⁽³⁾ value of 2.45 × 10^?8 esu for modified MMB‐PPV film decreased by over 5.3% when they had been exposed under the same ambient conditions for 90 days. © 2010 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 48: 2072–2077, 2010