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1.
聚苯胺钡铁氧体纳米复合材料的制备、表征及性能   总被引:8,自引:1,他引:7  
采用原位掺杂聚合法, 将聚苯胺(PANI)对粒径在60~80 nm的M型钡铁氧体颗粒(BaFe12O19)进行了包覆, 得到了具有棒状结构的复合材料. 通过X射线衍射(XRD)、傅里叶变换红外光谱(FTIR)、扫描电子显微镜(SEM)和透射电子显微镜(TEM)等测试手段对材料的形貌和结构进行了表征. 结果表明, PANI链段与BaFe12O19颗粒之间存在作用力. 使用振动磁强计和四探针法测定了复合材料的磁性能与电性能后发现, 饱和磁化强度与矫顽力均随聚苯胺含量的增加呈规律性下降趋势, 而电导率呈上升趋势. 复合材料的吸收特性测试结果表明, 该材料反射率小于-20 dB时, 带宽可以达到15.07 GHz. 同时详细地讨论了纳米复合材料的聚合机理及相互作用.  相似文献   

2.
以十二烷基萘磺酸(DNSA)为掺杂剂,在醇(或酮)-水介质中采用原位溶液聚合法制备了聚苯胺,以溶液共混法制备了聚苯胺/聚苯乙(PANI/PS)烯复合材料,采用红外光谱、热失重、元素分析和扫描电镜等手段对产物进行了表征.结果表明,掺杂的聚苯胺电导率最高为0.65S/cm,优于常用的十二烷基苯磺酸(DBSA),具有一定的实用价值和理论意义.该复合材料的表面电阻率最低为101Ω/□数量级,并在一定范围内可调,可用于电磁屏蔽,适合于聚合物表面使用.  相似文献   

3.
石墨烯/聚苯胺复合材料由于其优异的电学、热学、电化学性能和机械性能等特点,吸引了研究者们的广泛关注。本文对近几年来石墨烯/聚苯胺复合材料的发展状况进行了简单介绍,首先总结了原位聚合法、界面聚合法、自组装法、溶液共混法等不同制备方法对石墨烯/聚苯胺复合材料结构和性能的影响。由于石墨烯/聚苯胺复合材料结合了石墨烯和聚苯胺两者的优点,展现出更加优异的性能,因此本文还对其在超级电容器、传感器、燃料电池、太阳能电池等方面的应用进行了详细介绍。  相似文献   

4.
以氨基化的碳纳米管为基体,通过低温原位聚合的方法将聚苯胺共价接枝于碳纳米管表面,通过透射电镜(TEM)、X射线衍射(XRD)、紫外可见光(UV-vis)、傅里叶红外(FT-IR)、拉曼(Raman)及电化学方法对复合材料进行了表征.结果表明通过低温原位聚合的方法可以使聚苯胺均匀接枝于碳纳米管表面.电化学测试结果表明,碳纳米管共价接枝聚苯胺作为超级电容器材料在0.5 A/g条件下聚苯胺的电容贡献值为754.8 F/g,同时其倍率性能以及循环稳定性方面都明显优于聚苯胺非共价修饰的碳纳米管复合材料.  相似文献   

5.
采用化学共沉淀法制备了掺杂稀土铕的ATO纳米粉体。运用X射线衍射(XRD)、扫描电镜(SEM)等测试方法对ATO粉体进行表征,研究了制备工艺对粉体粒径和导电性能的影响,发现铕的摩尔掺杂比在0.5%~1%之间,600~700℃热处理温度下得到粉体的性能最佳,粉体的电阻率为243Ω.cm,颗粒尺寸为33.6 nm。掺杂前粉体的电阻率和颗粒尺寸分别为181Ω.cm和41.4 nm,掺杂后分别为243Ω.cm和33.6 nm。结果显示掺杂铕会使粉体的电阻率增加,但也能降低粒径,减少团聚。  相似文献   

6.
利用紫外光作为辅助条件,在反胶束体系中采用一步双原位法合成了硝酸(HNO3)、对甲基苯磺酸(TSA)和5-磺基水杨酸(SSA)掺杂的银/聚苯胺(Ag/PANI)纳米复合材料.通过对复合材料进行红外光谱(FTIR)、紫外光谱(UV-Vis)、扫描电镜(SEM)、X射线衍射(XRD)和导电性能的测试,研究了不同质子酸对Ag/PANI纳米复合材料结构、形貌和导电性能的影响.测试结果表明,3种酸掺杂制备的Ag/PANI纳米复合材料均为聚苯胺包覆银粒子的核-壳结构.不同的质子酸掺杂会对Ag/PANI纳米复合材料的电性能有重要影响.在3种酸掺杂的复合材料中,TSA掺杂的复合材料的电导率最佳,为215.14 S·cm-1.  相似文献   

7.
层层自组装原位聚合聚苯胺复合膜成膜机理研究   总被引:2,自引:0,他引:2  
从苯胺单体出发, 通过原位聚合、现场掺杂以及基于静电力的层层自组装制备了聚苯胺复合膜. 通过苯胺活性溶液的温度及颜色变化跟踪聚合反应进程, 同时考察不同聚合反应阶段所得聚苯胺复合膜的紫外-可见吸收, 并进一步探讨聚苯胺复合膜的成膜机理. 研究表明, 成膜机制是由聚合反应初始阶段的苯胺阳离子或苯胺阳离子自由基通过静电作用快速吸附到负电性的基片表面, 形成均匀的聚合中心, 链增长生成聚苯胺; 该聚苯胺在酸性条件下经现场掺杂显电正性, 可吸附电负性的聚苯乙烯磺酸钠(PSS), 以此循环层层组装得到多层聚苯胺复合膜.  相似文献   

8.
宋继中  贺英  潘照东  朱棣  陈杰  王均安 《化学学报》2011,69(13):1582-1588
首先用硅烷偶联剂(KH550)对所制备粒径在100 nm以下的纳米ZnO进行表面修饰(M-ZnO),然后在弱磁场(0.4T)下乙醇/水/十二烷基苯磺酸(DBSA)体系中原位聚合分别制备了重均分子量达3×104的聚苯胺(PANI)及聚苯胺/纳米ZnO复合材料.红外分析表明纳米ZnO的加入使聚苯胺的特征峰向低波数方向移动;...  相似文献   

9.
复合酸掺杂导电聚苯胺的合成及性能   总被引:4,自引:1,他引:3  
采用复合酸掺杂微乳液法合成导电聚苯胺. 探讨了反应温度和掺杂剂质量比对聚苯胺性能的影响,并通过四探针、塔菲尔曲线、激光粒度分析、热重分析以及红外光谱测试技术,对聚苯胺进行了研究与表征. 结果表明,当聚合温度为15 ℃、磺基水杨酸和十二烷基苯磺酸钠的质量比为2.5∶1时,掺杂态聚苯胺电导率和溶解度达到最大值,同时具有良好的防腐蚀能力;其中电导率可达11 S/cm,在氮甲基吡咯烷酮(NMP)中溶解度可达85%;经电化学工作站测试的塔菲尔曲线可知,其腐蚀电位为-0.391 V. 热重分析表明,复合酸掺杂聚苯胺热分解温度约为440 ℃;粒径分析表明,约有90%的聚苯胺颗粒集中在50~100 nm之间.红外光谱表明,复合酸掺杂聚苯胺各主要吸收峰均向低频方向移动,说明掺杂的有效性.  相似文献   

10.
炭黑/聚苯胺纳米复合粒子的制备与表征   总被引:1,自引:0,他引:1  
用现场原位聚合法制备了炭黑/聚苯胺纳米复合粒子,讨论了聚合反应条件对产物电导率的影响,并表征了复合粒子的形态和耐热性能.结果表明,所得的炭黑/聚苯胺纳米复合粒子粒度约为50 nm并具有核-壳结构,其电导率达30 S.cm-1,热分解温度约为600℃.  相似文献   

11.
Polypyrrole (PPy)-cellulose composites were prepared by in situ polymerization of pyrrole in pulp suspension using ferric chloride as an oxidant. Some sulfonic compounds including p-toluenesulfonic acid and its sodium salt (PTSA and PTSA-Na), benzenesulfonic acid (BSA), dodecylbenzene sulfonic acid and its sodium salt (DBSA and DBSA-Na), 2-naphthalene sulfonic acid (NSA) and 9,10-anthraquinone-2-sulfonic acid sodium salt (AQSA-Na) were used as dopants, and their effect on the conductivity of PPy-cellulose composite was investigated. The results showed that the species and dose of dopants had significant effect on the surface resistivity and environmental stability of PPy-cellulose composite. As the dopant, PTSA and DBSA had a superior doping effect compared to their sodium salts. The doping result of BSA was close to that of PTSA. NSA bearing a naphthalene ring and AQSA-Na bearing an anthraquinone ring gave the best conductivity. Using NSA or AQSA-Na as a dopant, along with suitable polymerization conditions, the PPy-cellulose composite obtained showed a surface resistivity as low as 20 Ω cm−2. For most dopants, the lowest surface resistivity could be obtained when the molar ratio of dopant to pyrrole was 1:1. Both ATR-FTIR (attenuated total reflection-Fourier transform infrared spectroscopy) and XPS (X-ray photoelectron spectroscopy) analysis confirmed that the PPy on pulp fibers doped with PTSA, PTSA-Na, NSA and AQSA-Na had different doping levels. The higher doping level of the PPy in the composites doped with NAS and AQSA-Na might be related to the stronger interaction of cellulose with PPy chains. Both SEM (scanning electron microscopy) and AFM (atomic force microscopy) observation revealed the fine grain microstructure of the PPy on the composites with average grain sizes in the range of 100–200 nm, and the PPy on the samples doped with NSA and AQSA-Na exhibited quite different morphology as compared to those doped with PTSA and its sodium salt.  相似文献   

12.
The focus of this study was to synthesize the inherently conductive polymer polyaniline using an optimized process to prepare polyaniline/silicon dioxide (PANI/SiO2) composites by in situ polymerization and ex situ solution mixing. PANI and PANI/SiO2 composite films were prepared by drop‐by‐drop and spin coating methods. The electrical conductivities of HCl doped PANI film and PANI/SiO2 composite films were measured according to the standard four‐point‐probe technique. The composite films exhibited an increase in electrical conductivity over neat PANI. PANI and PANI/SiO2 composites were also investigated by spectroscopic methods including UV‐Vis, FT‐IR, and Photoluminescence. UV‐Vis and FT‐IR studies showed that SiO2 particles affect the quinoid units along the polymer backbone and indicate strong interactions between the SiO2 particles and the quinoidal sites of PANI (doping effect). The photoluminescence properties of PANI and PANI/SiO2 composites were studied and the PANI/SiO2 composites showed increased intensity as compared to neat PANI. The increase of conductivity of PANI/SiO2 composite may be partially due to the doping or impurity effect of SiO2 where the silicon dioxides compete with chloride ions. The morphology of particles and films were examined by a scanning electron microscope (SEM). SEM measurements indicated that the SiO2 were well dispersed and isolated in composite films. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

13.
Polyamide 6 nanocomposites reinforced with Cu/Si nanoparticles (PA6-Cu/Si) were prepared by the in-situ ring-opening polymerization of ?-caprolactam. The in-situ polymerization was critical for preventing the aggregation of Cu/Si nanoparticles. The Cu/Si nanoparticles in the nanocomposite retained their nano characteristics and were not oxidized by the amino groups in PA6. The structure of the as-fabricated PA6-Cu/Si nanocomposite was evaluated by transmission electron microscopy (TEM), X-ray diffraction (XRD), and ultraviolet-visible absorption spectroscopy (UV-vis). The friction and wear resistance, mechanical strength, and antistatic performance of PA6-Cu/Si were also evaluated. The PA6 polymer chains prevent the Cu/Si nanoparticles from aggregation by coating the surface of the Cu/Si nanoparticles via physical adsorption or an electrostatic effect. The mass fraction of the Cu/Si nanoparticles also had a significant effect on the crystalline form of PA6. The γ crystalline form of PA6 was predominant at a high mass fraction of Cu/Si to PA6. Moreover, PA6-Cu/Si with improved mechanical properties and wear resistance was generated by tuning the amount of nano-Cu/Si filler added during the polymerization. PA6-Cu/Si with a nano-Cu/Si content of 0.5% possesses the highest tensile strength and wear resistance and shows promise in applications as a functional polymer-matrix composite.  相似文献   

14.

Uniform polyaniline nanofibers were prepared by interfacial polymerization. The nanofibers had a diameter of 80 nm and a length of about 1μm. The effect of centrifugal force on the morphology of the nanofibers is discussed. In situ UV‐Vis spectra indicated that the interfacial polymerization process was similar to the solution polymerization process. An “expanded‐partly doped” stage of interfacial polymerization was observed for the first time in the in situ UV‐Vis spectra.  相似文献   

15.
The enzyme horseradish peroxidase (HRP) was used to polymerize acid‐functionalized anilines to make self‐doped polymer in the presence of a polycationic template. Anionic templates such as sulfonated polystyrene (SPS) could not function as a suitable template for the polymerization of acid‐functionalized aniline derivatives. Several types of polyelectrolytes were used as templates to observe the structural effects and doping behavior of polyaniline/template complexes. The synthesis is straightforward and the conditions are mild in that the polymerization of conducting polyanilines may be carried out in buffered solutions as high as pH 6, with a stoichiometric amount of hydrogen peroxide and catalytic amount of enzyme. The conductivity of these enzymatically synthesized self‐doped polymers was relatively high without additional doping due to the self‐doping of the acid moieties. The conductivity did not decrease dramatically at pH 3 as is the usual case of unsubstituted HCl‐doped polyaniline and maintained good conductivity even at pH 6. The measured conductivity at pH 4~pH 6 is around 10?4 S/cm to 10?6 S/cm.  相似文献   

16.
β-萘磺酸掺杂聚苯胺纳米粒子的固相反应法制备及其表征   总被引:5,自引:0,他引:5  
利用固相反应法制备了 β 萘磺酸掺杂的聚苯胺纳米粒子 ,并以红外光谱 (FTIR) ,扫描电子显微镜(SEM) ,透射电镜 (TEM) ,X 射线衍射 (XRD)以及粉末微电极等测试方法对其进行了表征 .结果表明 ,固相反应法合成的 β 萘磺酸掺杂聚苯胺粒子直径为 30~ 5 0nm ,聚苯胺分子链排列有序 ,晶化率较好 .粉末微电极的循环伏安测试表明 ,β 萘磺酸掺杂聚苯胺有较好的电化学活性 .  相似文献   

17.
In this study, Ga‐doped ZnO thin films were prepared using sol–gel technique via spin‐coating method. The effect of Ga‐doping dopant (0, 1, 2 and 3 at.%) on microstructural, optical, electrical and photoelectrochemical (PEC) characteristics have been investigated. The spin‐coating was repeated six times, and as‐obtained thin films were then annealed at 500 °C for 1 h in vacuum. After annealing, all samples revealed single phase of hexagonal ZnO polycrystalline structure with a main peak of (002) in X‐ray diffraction (XRD) pattern. Raman spectra show that the vibration strength of E2 is highly decreased by Ga doping. Thicknesses of all samples were ~300 nm measured via scanning electron microscopy (SEM) cross‐section images and alpha‐step. The optical band gap and resistivity of samples were in the range of 3.24 to 3.28 eV and 102 to 9 Ohm cm, respectively. Resulting from PEC response, the 2 at.% Ga‐doped ZnO thin film has a better PEC performance with photocurrent density of ~0.14 mA/cm2 at 0.5 V versus saturated calomel electrode (SCE) under illumination with the intensity of 100 mW/cm2. This value was about seven times higher than the un‐doped film (reference sample). Observed higher photocurrent density was likely because of a suitable Ga‐doping concentration causing a lower resistivity. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

18.
The concept of the electronic-phase transition of the Hartree–Fock solution has been applied to an arbitrarily doped polyacetylene (PA) chain to examine the structural change of the polymer skeletons under such doping regimes. It has been found that the n-doped PA chain tends to suppress the generation of the charge-density wave (CDW ) phase, whereas the p-doped PA favors the CDW phase leading to the charged-soliton shape. © 1993 John Wiley & Sons, Inc.  相似文献   

19.
《先进技术聚合物》2018,29(1):594-602
Phosphoric acid (PA)–doped polybenzimidazole (PBI) proton exchange membranes have received attention because of their good mechanical properties, moderate gas permeability, and superior proton conductivity under high temperature operation. Among PBI‐based film membranes, nanofibrous membranes withstand to higher strain because of strongly oriented polymer chains while exhibiting higher specific surface area with increased number of proton‐conducting sites. In this study, PBI electrospun nanofibers were produced and doped with PA to operate as high temperature proton exchange membrane, while changes in proton conductivity and morphologies were monitored. Proton conductive PBI nanofiber membranes by using the process parameters of 15 kV and 100 μL/h at 15 wt% PBI/dimethylacetamide polymer concentration were prepared by varying PA doping time as 24, 48, 72, and 96 hours. The morphological changes associated with PA doping addressed that acid doping significantly caused swelling and 2‐fold increase in mean fiber diameter. Tensile strength of the membranes is found to be increased by doping level, whereas the strain at break (15%) decreased because of the brittle nature of H‐bond network. 72 hour doped PBI membranes demonstrated highest proton conductivity whereas the decrease on conductivity for 96‐hour doped PBI membranes, which could be attributed to the morphological changes due to H‐bond network and acid leaking, was noted. Overall, the results suggested that of 72‐hour doped PBI membranes with proton conductivity of 123 mS/cm could be a potential candidate for proton exchange membrane fuel cell.  相似文献   

20.
We report the synthesis of a water‐soluble diblock copolymer composed of polysulfonic diphenyl aniline (PSDA) and poly(ethylene oxide) (PEO), which was prepared by reacting an amine‐terminated PSDA and tosylate PEO (PEO‐Tos). First, a HCl‐mediated polymerization of sulfonic diphenyl aniline monomer with the formation of HCl‐doped PSDA was carried out. After its neutralization and reduction, a secondary amine‐functionalized PSDA was obtained. Second, PEO‐Tos was synthesized via the tosylation of the monohydroxyl PEO methyl ether with tosylol chloride. Diblock copolymers with various PEO segment lengths (PSDA‐b‐PEO‐350 and PSDA‐b‐PEO‐2000) were obtained with PEO‐350 [number‐average molecular weight (Mn) = 350] and PEO‐2000 (Mn = 2000). The prepolymers and diblock copolymers were characterized by Fourier transform infrared spectroscopy, NMR, mass spectrometry, and ultraviolet–visible light. They had relatively low conductivities, ranging from 10?6 to 10?3 S/cm, because of the withdrawing effect of the sulfonic group as well as the steric effects of the bulky aromatic substitutuents at the N sites of the polyaniline backbone and of the PEO block. These polymers were self‐doped, and an intermolecular self‐doping was suggested. The external doping was, however, more effective. The self‐doping induced aggregation in water among the PSDA backbones, which was also stimulated by the presence of hydrophilic PEO blocks. Furthermore, the electrical conductivities of the diblock copolymers were strongly temperature‐dependent. PSDA‐b‐PEO‐2000 exhibited about one order of magnitude increase in conductivity upon heating from 32 to 57 °C. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2179–2191, 2004  相似文献   

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