十二烷基苯磺酸掺杂聚苯胺的气敏性能研究

以苯胺为单体,过硫酸铵为氧化剂,采用化学氧化聚合法分别在十二烷基苯磺酸(DBSA)和盐酸中合成了聚苯胺(PAn),并用傅里叶红外光谱和TGA-DTA技术对聚苯胺掺杂前后的结构变化和热稳定性进行了分析。研究了不同质子酸掺杂对聚苯胺气敏性能的影响。结果表明:十二烷基苯磺酸掺杂的聚苯胺,比普通盐酸掺杂的聚苯胺对目标气体具有更好的灵敏性。当r(S:N)为0.4～0.5时,在室温下其对1000×10-6NH3的灵敏度达到了10.43,响应时间为30s,恢复时间为3min。且与盐酸相比,十二烷基苯磺酸掺杂的聚苯胺具有更好的环境稳定性。     

导电聚苯胺(PAn)材料在EMI中的应用

聚苯胺(PAn)是一种极有实用价值的导电高分子材料,在EMI领域具有广泛的应用.文章概述导电聚苯胺(PAn)在高压电器、通讯电缆电线、纺织化纤、电子元器件封装、导电涂料、微波吸收剂等方面的应用情况,并提出了今后研究及开发的方向.     

微波场中油页岩及半焦升温特性

在自行设计的微波干馏装置上研究了汪清和桦甸几个矿区的油页岩和半焦在微波场中升温特性.实验研究了产地、组成成分对油页岩升温特性的影响,不同干馏终温生成的半焦及石墨在微波场中的升温特性,以及半焦和油页岩混合物在微波场中的升温特性.实验结果表明:油页岩是一种微波弱吸收物质,要想热解必须加入微波吸收剂.水分对油页岩在微波场中的升温特性影响很大.油页岩干燥以后,升温速率明显减小,终温也降低.油页岩中的黄铁矿对升温也有一定的影响.半焦由于在微波场中升温很快可以作为油页岩热解的微波吸收剂.半焦的升温速率与干馏终温有关,随着干馏终温提高,半焦在微波场中的升温速率变大.半焦和页岩的混合物在微波场中升温很快,具有良好的热解效果.     

有机磺酸掺杂聚苯胺的光电性能

对十二烷基苯磺酸（ Ｄ Ｂ Ｓ Ａ） 掺杂的聚苯胺进行了光电性能测试,结果表明： Ｄ Ｂ Ｓ Ａ 掺杂的聚苯胺在光照射下,光生载流子明显增大;感光材料的加入有利于聚苯胺在可见光区的吸收,并增加其导电性。对 Ａｌ－ Ｐ Ａｎ － Ｄ Ｂ Ｓ Ａ－ Ａｌ 结构的介电弛豫研究表明,在 Ｄ Ｂ Ｓ Ａ 掺杂聚苯胺的薄膜中存在空间电荷极化现象。通过理论计算与测试得知,掺杂态聚苯胺的寿命为微秒级, 迁移率为１ ×１０ － ３ ～１ ×１０ － １ ｃｍ ２／（ Ｖ·ｓ） 。从聚苯胺的电导率与温度关系中得到该材料的活化能,并分析了掺杂态聚苯胺的导电机理。     

导电聚苯胺在太赫兹波段的光电性能研究

导电聚苯胺是一种掺杂高分子半导体,内部含有大量的自由载流子,同时含有大量被束缚的载流子。本文利用太赫兹时域光谱装置测量了不同电导率的聚苯胺在0.3～2.8 THz的光谱特性,得到了其在太赫兹波段的吸收系数、折射率和介电常数等光电参数。研究了电导率对其吸收系数、折射率和介电常数的影响,对半导体材料中载流子与太赫兹波的相互作用的研究具有重要意义。     

导电聚苯胺在铝电解电容器中的应用

导电高分子在电子元件中的应用十分广泛。比较了几种用于铝电解电容器中的固体电解质:二氧化锰、TCNQ、聚吡咯、聚苯胺,其中聚吡咯、聚苯胺的性能优势明显,尤其是聚苯胺的电导率和热稳定性最好。介绍了聚苯胺结构特征、合成方法以及聚苯胺铝电解电容器的制造方法和性能,展望了聚苯胺的应用前景。     

掺杂聚苯胺有机高分子发光器件

采用聚苯胺作阳极,ＭＥＨ－ＰＰＶ作发光材料,我们合成了有机高分子发光二极管器件．通过对聚苯胺的掺杂,发现器件的发光强度比未掺杂器件提高３０％,起始工作电压降低２５％．寿命测量还显示以聚苯胺或掺杂聚苯胺作电极的二极管器件,在给定电压下的工作寿命要比直接用导电玻璃作电极的二极管器件提高７～１０倍以上．     

质子酸掺杂聚苯胺的制备及其常温气敏性能

以苯胺为单体,过硫酸铵为氧化剂,采用化学氧化聚合法,在酸性介质中合成了聚苯胺。并用FT-IR光谱和UV-Vis光谱对聚苯胺掺杂前后的结构变化进行了分析,研究了不同质子酸掺杂对聚苯胺气敏性能的影响。结果表明,经质子酸掺杂后的聚苯胺,在室温下对NH3具有较好的灵敏度,其中结果最好的1mol/LH2SO4掺杂的聚苯胺对500×10–6NH3的灵敏度达到了10.86。     

导电聚苯胺／羰基铁粉复合吸收效能的研究

利用软磁金属粉末羰基铁粉的良好电磁吸收特性,加入不等量的导电聚苯胺,制备成导电聚苯胺／羰基铁粉复合材料。在1．8mm厚的涂层中,随导电聚苯胺含量的增加,其吸波效能得到显著改善。分析表明,导电聚苯胺／羰基铁粉有利于发展成为轻质、宽频、强吸收的优良吸波材料。     

石墨烯/聚苯胺纳米复合材料的制备及防腐应用研究进展

导电聚苯胺(PANI)具有易合成、易掺杂等特点,石墨烯(GR)及石墨烯衍生材料具有较高的比表面积、良好的导电性、优异的防液体渗漏等物理和化学性质。两者的复合材料表现出优异的机械、电化学、防腐蚀等性能,引起了广泛的关注。介绍了石墨烯/聚苯胺纳米复合材料的制备方法、影响石墨烯/聚苯胺性能的主要因素以及石墨烯/聚苯胺纳米复合材料在防腐中的应用。系统总结了石墨烯/聚苯胺的防腐机理以及在不同基体涂料中的防腐改性,石墨烯的存在增加了腐蚀介质(如H2O和O2)渗透路径的曲折程度,减缓了金属腐蚀速度,从而提高涂料防腐效率。石墨烯/聚苯胺复合材料在防腐方面具有广阔的应用前景,对石墨烯/聚苯胺的复合状态、防腐机理、环境适应性的深入研究是未来该材料的发展方向。     

Polymer light‐emitting diode prepared with an ionomer and polyaniline

Light‐emitting diodes of poly[2‐methoxy‐5‐(2′‐ethyl‐hexyloxy)‐1,4‐phenylenevinylene] (MEH‐PPV) have been fabricated from sodium sulphonated polystyrene (SSPS) ionomer as an electron‐injecting and hole‐blocking material and polyaniline doped with camphor sulphonic acid (PANI‐CSA) as a polymer anode. The presence of PANI in an ITO/PANI/MEH‐PPV/AI device makes little difference to its optical output and quantum efficiency. SSPS shows good electron injection in an ITO/MEH‐PPV/SSPS/AI device. When SSPS ionomer is introduced in an ITO/PANI/MEH‐PPV/SSPS/A1 device, a larger enhancement in optical output is obtained and its quantum efficiency is also enhanced because of its balanced charge injection. The electroluminescent device associated with SSPS ionomer and PANI is a well‐designed structure to improve stability and efficiency. Copyright © 2000 John Wiley & Sons, Ltd.     

Chlorine gas sensors using hybrid organic semiconductors of PANI/ZnPcCl16

PANI/ZnPcCl_(16)(polyaniline doped with sulfosalicylic acid/hexadecachloro zinc phthalocyanine) powders were vacuum co-deposited onto Si substrates,where Pt interdigitated electrodes were made by micromachining.The PANI/ZnPcCl_(16) films were characterized and analyzed by SEM,and the influencing factors on its intrinsic performance were analyzed and sensitivities of the sensors were investigated by exposure to chlorine(Cl_2) gas.The results showed that powders prepared with a stoichiometric ratio of(ZnPc...     

Synthesis of novel NiZn-ferrite/Polyaniline nanocomposites and their microwave absorption properties

Novel Ni_0.5Zn_0.5Fe₂O₄ (NiZn-ferrite)/Polyaniline (PANI) nanocomposites with NiZn ferrite nanoparticles on the surface of PANI nanofibers were successfully prepared by hydrothermal method. The composites were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared (FTIR), and UV–vis spectra. The results indicate that the PANI nanofibers (80 nm in thickness) are attached by NiZn ferrite nanoparticles. Compared with pure PANI, the thermal stability of composites is improved clearly. The NiZn-ferrite/PANI nanocomposites exhibit ferromagnetic behavior with high saturation magnetization (Ms=43.7 emu/g) and coercivity (Hc=138.7 Oe) at room temperature. The microwave absorption properties of these composites were measured, and the absorption bandwidth with reflection loss below ?10 dB is up to 5 GHz. The composites could further extend the potential application in microwave absorption and electromagnetic interference shielding fields.     

Effective Photothermal Killing of Pathogenic Bacteria by Using Spatially Tunable Colloidal Gels with Nano‐Localized Heating Sources

Alternative approaches to treating subcutaneous abscesses—especially those associated with antibiotic‐resistant pathogenic bacterial strains—that eliminate the need for antibiotics are urgently needed. This work descibes a chitosan (CS) derivative with self‐doped polyaniline (PANI) side chains that can self‐assemble into micelles in an aqueous environment and be transformed into colloidal gels in a process that is driven by a local increase in pH. These self‐doped PANI micelles can be utilized as nano‐localized heat sources, remotely controllable using near‐infrared (NIR) light. To test the in vivo efficacy of the CS derivative as a photothermal agent, an aqueous solution thereof is directly injected at the site of infected abscesses in a mouse model. The injected polymer solution eventually becomes distributed over the acidic abscesses, forming colloidal gels when it meets the boundaries of healthy tissues. After treatment with an 808 nm laser, the colloidal gels convert NIR light into heat, causing the thermal lysis of bacteria and repairing the infected wound without leaving residual implanted materials. This approach has marked potential because it can provide colloidal gels with tunable spatial stability, limiting localized heating to the infected sites, and reducing thermal damage to the surrounding healthy tissues.     

Enhancement of Electrical Properties of Ferroelectric Polymers by Polyaniline Nanofibers with Controllable Conductivities

Conductive nanofibers are adopted to enhance the electric properties of ferroelectric polymers. Polyaniline (PANI) nanofibers doped by protonic acids have a high dispersion stability in vinylidene fluoride‐trifluoroethylene copolymers [P(VDF‐TrFE)] and lead to percolative nanocomposites with enhanced electric responses. About a 50‐fold rise in the dielectric constant of the ferroelectric polymer matrix has been achieved. Percolation thresholds of the nanocomposites are relevant to doping levels of PANI nanofibers and can be as low as 2.9 wt% for fully doped nanofibers. The interface between the conductive nanofiber and the polymer matrix plays a crucial role in the dielectric enhancement of the nanocomposites in the vicinity of the percolation threshold. Compared with other dopants, perfluorosulfonic acid resin is better at improving the performance of the nanofibers in that it serves as a surface passivation layer for the conductive fillers and suppresses leakage current at low frequency. The nanofibers drastically reduce the electric field strength required to switch spontaneous polarization of P(VDF‐TrFE). The nanocomposites can be utilized for potential applications as high energy density capacitors, thin‐film transistors, and non‐volatile ferroelectric memories.     

Study on hard X-ray absorbing properties of nanocluster polyaniline

Attenuation of X-ray materials based on polyaniline (PANI) as non-toxic material were fabricated and investigated. PANI was prepared by chemical polymerization in presence of HCl, para-toluene sulfonic acid (PTSA), camphor sulfonic acid (CSA), dodecyl benzene sulfonic acid (DBSA) and lignin sulfonic acid (LSA) with double acts as surfactant, dopant and ammonium persulphate (APS) as oxidant. The morphology, thermal stability and electrical conductivity of resulting PANI were characterized by scanning electron microscopy (SEM), fourier transform infrared (FTIR) spectroscopy and standard four-wire-technique, respectively. In order to evaluate capability of PANI in radiation shielding, X-ray photon interaction parameters such as linear attenuation coefficient, attenuation percentage and half value thickness were determined for the samples with different dopants and thicknesses, at photon energies of 13.95, 17.74, 20.08, 26.34, 59.50 keV as hard X-ray. The investigation was carried out to explore the potential of PANI as thin and light weight radiation shielding materials without toxic heavy metals.     

Formation of Polyaniline Nanorod/Liquid Crystalline Epoxy Composite Nanowires Using a Temperature‐Gradient Method

Liquid crystalline epoxy/polyaniline (LCE/PANI) composite nanowires have been fabricated using an anodic aluminum oxide (AAO) membrane by a temperature‐gradient curing process. PANI nanorods with an average diameter of 30 nm have been synthesized by dispersion polymerization in order to employ them as a curing agent for LCE and as a reinforcement filler for the LCE/PANI composite nanowires. Differential scanning calorimetry and Fourier‐transform infrared spectroscopy indicate that the LCE crosslinking reaction occurred inside the channels of the AAO membrane via the curing of LCE with PANI nanorods. The LCE/PANI composite nanowires exhibit an enhanced electrical conductivity and thermal stability, comparable with a LCE/PANI composite monolith. In addition, these polymer‐composite nanowires also display the characteristics of a functionally gradient conducting material.     

LD端面泵浦变热传导系数Nd:YAG晶棒温场特性

为了解决激光二极管泵浦激光晶体产生的热效应问题,对激光晶体内的温升进行了解析分析与定量计算。通过对激光二极管端面泵浦激光晶体工作特点的分析,建立了符合实际工作情况的热模型。考虑到晶体材料热传导系数受其宏观温度变化的影响,应用常数变易法以及特征函数法得到了变热传导系数Nd:YAG晶体棒在端面泵浦情况下温度场的一般表达式。定量计算了激光二极管超高斯分布泵浦光阶次、泵浦功率、光斑尺寸以及晶棒半径对其温度场分布的影响。研究结果表明:使用输出功率为60 W的激光二极管端面泵浦掺钕离子质量分数1.0%的Nd:YAG晶棒,若耦合入射的3阶超高斯光束泵浦光斑半径为400μm,晶棒半径为1.5 mm,长度为8 mm时,Nd:YAG棒内最大温升为343.9℃;而将其热导率视为定值时,晶体的最大温升只有222.7℃。研究结果为正确计算Nd:YAG晶体温度场分布提供了方法,并为提高全固态Nd:YAG激光器性能提供了理论依据。     

掺杂YAG和GGG激光晶体热导率研究

为了研究不同掺杂YAG和GGG激光晶体的导热特性,采用瞬态脉冲法测量了273K~393K温度范围内自己生长的不同掺杂YAG和GGG激光晶体的热导率,并建立了实验样品温度场模型,推导出热导率对温度的函数关系,得到晶体热导率随温度变化曲线,这与实验测量结果基本相符。实验结果表明,晶体热导率随温度升高呈下降趋势,YAG激光晶体经Yb离子掺杂后热导率值降低,GGG晶体热导率随掺杂Nd离子浓度的增加而降低,并从理论上对实验结果进行了解释。     

Thermal conductivity of doped YAG and GGG laser crystal

To study the thermal conduction characteristics of different doped YAG and GGG laser crystals, the thermal conductivity of different doped YAG and GGG laser crystals generated at 273-393 K were measured by making use of instantaneous measurement method. The temperature field model of the experimental sample was established and the function of thermal conductivity to temperature was educed. The obtained conductivity to temperature curves almost conformed to the experimental results. The experimental results show that the thermal conductivity of the laser crystal decline with temperature,the thermal conductivity of YAG laser crystal declines when adding Yb ions, and the thermal conductivity of the GGG laser crystal declines with the rising of the doped Nd ions concentration. Finally, the experimental results were theoretically explained.