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1.
A new organic semiconductor tartaric acid doped salt of emeraldine polyaniline(PANI-C4H6O6)has been obtained by the method of oxidative polymerization of monomeric aniline with ammonium persulfate in acidic solution.The structure was characterized by Fourier Transform Infrared technique(FTIR) and X-ray diffraction(XRD).The temperature dependence dc conductivity δdc(T)shows a semiconductor behavior and follows the quasi one dimensional variable range hopping(Q1D-VRH)model.Data on δdc(T) are also discussed.  相似文献   

2.
通过乳液聚合法制备纳米聚苯胺,使用十二烷基苯磺酸(DBSA)作为掺杂剂,在聚苯胺链上引入直链烷基,得到可溶性纳米聚苯胺(PANI-DBSA)复合物。研究了DBSA含量对PANI-DBSA复合物溶解度和电导率的影响,及制备过程中聚苯胺的生成和最终产物的紫外-可见光特征。结果表明:聚苯胺颗粒分散性好,粒径为20~100nm,当DBSA与苯胺单体摩尔比为3.0时,聚合物在甲苯中的溶解度最高为3.76%,当DBSA与苯胺单体摩尔比为1.0,聚合物导电性最好,电导率为250.4S/m。PANI-DBSA复合物在波长300~800nm具有良好的吸收性能。  相似文献   

3.
导电聚苯胺在微波场中的升温特性   总被引:5,自引:0,他引:5       下载免费PDF全文
本文研究了微波辐照下导电聚苯胺的升温特性。研究表明 ,导电聚苯胺在微波场中具有快速升温的特点 ,升温速度与掺杂剂的种类、掺杂酸的浓度、聚苯胺的导电率、合成聚苯胺的温度等因素有关。盐酸掺杂聚苯胺热稳定性较差 ,在微波场中不能反复升温 ,而热稳定性较好的DBSA掺杂的聚苯胺具有一定的反复升温能力  相似文献   

4.
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。  相似文献   

5.
采用苯胺,过(二)硫酸铵(NH4)2S2O8、硝酸银AgNO3、甲醛、十二烷基苯磺酸钠等为原料,合成了银-DBSA掺杂的聚苯胺。最佳合成的具体条件:反应温度在0~5℃下,苯胺、(NH4)2S2O8和十二烷基本磺酸钠摩尔比为4:4:1,加入的AgNO3的物质的量为苯胺的10%,反应4.5小时后,再加适量的甲醛还原得到银-DBSA掺杂聚苯胺。样品的IR光谱表明,通过还原后峰型和峰位都发生了明显的变化。样品的XRD分析知,银-DBSA掺杂聚苯胺有很强的金属元素银的峰,样品的SEM表明,还原得到的银-DBSA掺杂聚苯胺的颗粒度更小,且有许多银白色的银粒分散在高聚物大分子中。样品的TG热分析表明,银-DBSA掺杂聚苯胺在420℃以下是很稳定的,说明掺入银后的聚苯胺的热稳定性得到了显著的增强。用四探针电阻仪测试样品的电导率约为14S/cm,因此它是很有希望用于全印制电路技术的新材料。  相似文献   

6.
1IntroductionAsanewkindofconductingpolymer,polyparaphenylene(PPP)isthepointofatentionformanyscholarsduetoitslowcost,simplesyn...  相似文献   

7.
以过硫酸铵为氧化剂,采用自稳定分散聚合法(SSDP)合成高导电态聚苯胺(PANI)。研究了不同种类的表面活性剂对PANI形貌与性能的影响,通过TEM、FT-IR、XRD、UV-Vis及四探针实验分别对PANI进行分析表征。结果表明,添加阴离子型表面活性剂十二烷基苯磺酸(DBSA)所得的PANI呈纳米纤维状,添加非离子表面活性剂聚乙二醇(PEG400)和阳离子表面活性剂三乙醇胺(TEA)所得的PANI分别呈扇形树枝状和薄膜状;添加DBSA所得PANI电导率最高,为8.7 S.cm–1,而添加PEG400所得聚苯胺产率最高,为78.3%。  相似文献   

8.
To sensitize polyaniline with dyes by electrochemical polymerization,HClO4 is employed as the dopant and oxidant,and the polyaniline with differnet sensitive properties is synthesized.The effect of sensitized emeraldine salt on the absorption spectrum is discussed in details.The maximum conductivity of sensitized films reaches 1.22S/cm,and investigation on dye sensitizing of the polymer reveals that C.I.Direct Blue 71,C.I.Direct Blue 84,C.I.Direct Black 19 and CuPc-(COOH)4 may enhance the photoconductivity of polyaniline greatly.  相似文献   

9.
为解决脉冲激光二极管端面泵浦Nd:YAG晶体产生瞬态热效应的问题,对激光晶体内的温场分布进行了解析分析与定量计算。通过对脉冲激光二极管端面泵浦激光晶体工作特点分析,建立了端面绝热、周边恒温的晶体热模型,考虑到Nd:YAG晶体导热系数与其温度的函数关系,引入弦截法求解含时热传导方程,得出了变热传导系数方形Nd:YAG晶体时变温度场的一般解析表达式。定量分析了变热传导系数方形Nd:YAG晶体在不同超高斯阶次和光斑半径下内部温度场时变情况。计算结果表明:使用平均输出功率为60 W 的脉冲激光二极管端面泵浦掺钕离子质量分数1.0%的Nd:YAG 晶体,若入射的3阶超高斯光束泵浦光光斑半径为400 m,则晶体尺寸为4 mm4 mm8 mm的Nd:YAG晶体在达到准热平衡状态时的最高和最低温升分别为364 K和337 K。研究结果为正确计算Nd:YAG晶体温度场分布提供了方法,并对解决激光晶体热效应问题提供了理论依据。  相似文献   

10.
The electrical conductivity, thermoelectric power (TEP), and optical properties of organo-soluble polyaniline doped with HCl have been investigated. The electrical conductivity and TEP of the sample increase with increasing temperature. The electrical conductivity and TEP results of the polymer suggest that it is a p-type semiconductor. The fundamental absorption edge in the polymer is formed by the direct allowed transitions, and the optical band gap value was found to be 2.79 eV. The absorption spectra for an acidic solution of the polymer indicate two new absorption bands, which are due to polaron formation. The polaron bands are responsible for the conductivity of the polymer. The TEP results indicate that the conductivity mechanism of the polymer is controlled by the large polaron hopping model.  相似文献   

11.
封伟  吴洪才  曹猛 《半导体光电》1999,20(6):428-431
对用酞菁铜功能基改性的两种分子结构的聚苯胺( 掺杂型和接枝型) 进行了光电性能的测量。根据紫外吸收谱发现,用酞菁铜磺酰氯接枝的聚苯胺和酞菁铜磺酸掺杂的聚苯胺均在可见光区、近红外区具有较强的吸收。使用光源照射改性后的聚苯胺片材及薄膜,光电流显著增长,酞菁铜磺酰氯接枝的聚苯胺经照射后光电流最大可达到10 m A( 电压为0 .5 V) 。可见,用酞菁铜功能基改性的聚苯胺光电导性能得到改善。  相似文献   

12.
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。  相似文献   

13.
We explore the charge transport properties of phytic acid (PA) doped polyaniline thin films prepared by the surfactant monolayer-assisted interfacial synthesis (SMAIS). Structural and elemental analysis confirms the inclusion of PA in the thin films and reveals a progressive loss of crystallinity with the increase of PA doping content. Charge transport properties are interrogated by time-resolved terahertz (THz) spectroscopy. Notably, independently of doping content and hence crystallinity, the frequency-resolved complex conductivity spectra in the THz region can be properly described by the Drude model, demonstrating band-like charge transport in the samples and state-of-the-art charge carrier mobilities of ≈1 cm2V−1s−1. A temperature-dependent analysis for the conductivity further supports band-like charge transport and suggest that charge carrier mobility is primarily limited by impurity scattering. This work highlights the potential of PA doped polyaniline for organic electronics.  相似文献   

14.
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。  相似文献   

15.
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.  相似文献   

16.
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.  相似文献   

17.
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。  相似文献   

18.
A study is reported of absorption, conductivity, and photoconductivity of photosensitive μc-Si:H weakly doped with boron. The dependences of photoconductivity on the temperature and the intensity of light were measured in a temperature range of 100–400 K for photon energies of 0.9, 1.3, and 1.8 eV. The results obtained are explained by the dominant contribution of the microcrystalline phase and the states at the interfaces of microcrystals to the transport and recombination of nonequilibrium carriers in μc-Si:H. Possible recombination mechanisms and the change of their role with temperature are analyzed.  相似文献   

19.
A good light trapping scheme is necessary to improve the performance of amorphous/microcrystalline silicon tandem cells. This is generally achieved by using a highly reflective transparent conducting oxide/metal back contact plus an intermediate reflector between the component cells. In this work, the use of doped silicon oxide as alternative n‐layer in micromorph solar cells is proposed as a means to obtain high current values using a simple Ag back contact and no extra reflector between the component cells n‐doped silicon oxide layers with a wide range of optical and electrical properties have been prepared. The influence of different deposition regimes on the material properties has been studied. The main findings are the following: (i) when carbon dioxide is added to the gas mixture, sufficiently high hydrogen dilution is necessary to widen the transition region from highly conductive microcrystalline‐like films to amorphous material characterized by low electrical conductivity; (ii) lower refractive index values are found with lower deposition pressure. Optimal n‐doped silicon oxide layers have been used in both component cells of micromorph devices, adopting a simple Ag back contact. Higher current values for both cells are obtained in comparison with the values obtained using standard n‐doped microcrystalline silicon, whereas similar values of fill factor and open circuit voltage are measured. The current enhancement is particularly evident for the bottom cell, as revealed by the increased spectral response in the red/infrared region. The results prove the high potential of n‐doped silicon oxide as ideal reflector for thin‐film silicon solar cells. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

20.
The thermoelectric properties of the Mg2Ge0.3Sn0.7 solid solution doped with Ga and Li are studied. The samples with a hole concentration as high as 5 × 1020 cm–3 are obtained. The temperature dependences of the thermopower, electrical conductivity, and thermal conductivity are measured in the range from room temperature to 800 K. A higher mobility of free charge carriers is observed in the samples doped with lithium than in the samples doped with gallium. The largest thermoelectric figure of merit in the samples under study amounts to 0.42 at 700 K.  相似文献   

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