乙烯基化二氧化铈表面改性研究

为了提高CeO_2的表面性能,采用乙烯基三甲氧基硅烷(VTMOS)作为表面改性剂,冰乙酸、氨水作pH值调节剂,对CeO_2粉末进行表面改性。通过沉降实验、TG和FTIR等测试手段分析了溶液体系、改性时间、改性温度对CeO_2表面性能的影响,并且研究了改性后CeO_2与聚苯胺(PANI)形成复合材料的电化学性能。结果表明,在60℃醇水体系中改性2 h对CeO_2表面改性效果最好,其疏水性和热稳定性均得到提高;在65 g/L Zn~(2+)、150 g/L H_2SO_4电解液中,PANI、PANI/CeO_2、PANI/改性CeO_2复合材料的析氧过电位分别为0.659 V、0.679 V、0.652 V,说明改性CeO_2表现出更好的电催化活性,从而扩展了CeO_2在导电高分子材料领域的应用。     

用掺杂HDEHP的聚苯胺固相萃取剂萃取分离La~(3+)试验研究

探讨了用掺杂HDEHP的聚苯胺(PANI)固相萃取剂萃取分离稀土镧,考察了HDEHP掺杂量、水相酸度、萃取时间、固体萃取剂用量对镧萃取效果的影响。结果表明:在萃原液pH为3.0、两相接触时间30 min、固相萃取剂中V(HDEHP)/m(PANI)=0.60 mL/g、固相萃取剂用量0.30 g条件下,镧的常温萃取率为56.17%。     

温度对微波水热辅助合成有机酸掺杂聚苯胺结构和性能的影响

为了探究反应温度对微波水热辅助合成有机酸掺杂聚苯胺(polyaniline,PANI)分子结构及其性能的影响,选择对甲基苯磺酸(p-toluenesulfonic acid,TSA)作为反应溶液,通过化学氧化法合成PANI,并借助场发射扫描电子显微镜(field emission scanning electron microscopy,FESEM)、傅里叶变换红外光谱仪(Fourier transform infrared spectrometer,FT-IR)、紫外可见光谱仪(ultraviolet visible spectrometer,UV-vis)、凝胶色谱仪(gel permeation chromatography,GPC)、热重分析仪(thermal gravimetric analyzer,TGA)和电化学工作站,对其结构和性能进行了表征和分析。结果表明:0℃时合成的PANI为球状,且表面均匀分散着纳米粒子;30和50℃时合成的PANI为纳米纤维结构;随着合成温度的升高,PANI分子链共轭性增强、分子量增加,PANI的热稳定性提高,但电化学性能变差。     

具有微米纤维碳的硅/石墨/碳复合材料的制备及在锂离子电池中的应用

以沥青为软碳原料,商业石墨的载体材料,通过高温热解法成功合成了硅/石墨/碳复合材料,同时原位生成了微米尺度的碳纤维.该硅/石墨/碳复合材料具有诸多优点,石墨片层堆叠之间的空隙为硅的体积膨胀提供了有效的空间,沥青热解碳材料的包覆能一定程度抑制硅基材料的体积效应和提高其电子电导率,同时微米级的碳纤维能提高材料的长程导电性和结构稳定性,从而极大的改善负极材料循环性能.通过电化学测试表明,硅/石墨/碳复合材料中硅/石墨/碳复合负极材料在200 mA·g-1电流密度下具有650 mA·h·g-1的可逆容量,在200 mA·g-1电流密度下经过500圈循环后容量保持率为92.8%,每圈的容量衰减率仅为0.014%,展现了优异的循环性能.      

金属W掺杂AgSnO2材料导电性能研究

AgSnO₂作为电接触材料成功替代AgCdO材料,但是使用过程中析出的SnO₂是宽禁带半导体,在导电性方面同AgCdO材料相比较差,因此决定通过掺杂W元素来提升SnO₂材料的导电性。依据第一性原理,利用Material Studio软件中的CASTEP模块对SnO₂晶体进行不同浓度比(50%,25%,16.7%,12.5%,8.35%,6.25%,5%)的W元素掺杂,并计算其结构参数、焓变、能带结构、态密度、电荷布局等特性。分析得出,任意掺杂后的SnO₂结构较未掺杂前焓变绝对值增大,新生成O-W键与O-Sn键键长相差不大,掺杂后可以生成稳定结构;由于W元素的掺杂,其特有的d轨道不仅能提供更多能量,同时与O的耦合作用使能带间隙减小,当掺杂比为6.25%时其间隙可减小到0.008 eV,能带图中导带底与价带顶近似重合;掺杂后总电荷量增加,载流子浓度提升;通过计算确定在掺杂比为6.25%时材料的导电性最好,电导率较未掺杂前有大幅度提升。计算结果为后续研究提供了理论基础。     

Zr、Ti元素掺杂对高比重W-Cu-Ni/Y2O3复合材料的显微组织和性能的影响规律研究

通过高能球磨法制备了多元掺杂高比重W-Cu-Ni/Y2O3粉末,经放电等离子烧结制得高比重W-Cu-Ni/Y2O3复合材料,研究分析了材料显微组织、晶体结构和力学性能.结果表明:掺杂质量分数1.5％Zr、1.5％Ti元素所制备的粉体具有良好的烧结性能,经SPS烧结后相对密度超过99.5％.同时,所制得的复合材料具有更好...     

导电聚苯胺对La_(0.8)Mg_(0.2)Ni_(3.4)Al_(0.1)储氢合金电化学性能的影响

研究了超声辅助下在La_(0.8)Mg_(0.2)Ni_(3.4)Al_(0.1)合金颗粒表面沉积导电聚苯胺(PANI)对合金形貌和电化学性能的影响。XRD分析表明,该合金为多相结构,合金主相为Gd2Co7型相。SEM照片表明,超声辅助下在合金颗粒局部表面沉积了聚苯胺层。电化学性能研究表明,随着聚苯胺溶液浓度的增加,合金/PANI复合物电极放电容量逐渐下降,循环性能先提高后下降。当聚苯胺溶液浓度为4%时,样品在300次电化学循环后容量保持率达到71.2%。Tafel曲线测试表明,合金表面聚苯胺层的存在降低了电极腐蚀电流密度,从而提高了合金/PANI复合物循环性能。     

固相聚合反应制备聚苯胺结构及性能研究

利用固相聚合反应室温下制备不同质子酸掺杂的聚苯胺.对盐酸掺杂的聚苯胺进行X射线衍射（XRD）、差热-热重分析（DSC-TGA）和红外光谱测试（FT-IR）,结果表明盐酸掺杂的聚苯胺有良好的结晶性和稳定性,通过测定不同质子酸掺杂的聚苯胺的电阻率及在氯仿中的溶解性,表明固相反应法可以合成导电性和溶解性较好的聚苯胺.     

聚苯胺包覆硒化镍的制备与析氢性能

采用水热和电化学沉积两步法制备泡沫镍(NF)负载的聚苯胺(PANI)包覆硒化镍(NiSe)析氢电极(PANI/Ni Se/NF),利用扫描电镜(SEM)、能谱仪(EDS)、X射线衍射(XRD)、X射线光电子能谱仪(XPS)以及电化学测试等手段对材料进行形貌、组成及电化学性能表征。结果表明,以氯化镍为镍源,用水热法可制备出泡沫镍负载的针状Ni Se,使用导电聚合物聚苯胺包覆不改变其形貌。PANI/Ni Se/NF电极的双电层电容为12 560μF/cm~2,大于NiSe/NF电极的9 200μF/cm~2,拥有更大的电化学活性面积,其析氢起始过电位比未包覆时降低了58 mV,Tafel斜率为133 mV/dec。电流密度为10 mA/cm~2时,PANI/Ni Se/NF电极的析氢过电位为203 mV,展示出优异的析氢催化活性。导电聚合物PANI的包覆不仅可提高硒化镍电极的析氢活性,而且可减小电荷转移电阻,加快电荷转移速率,并显著提高电极稳定性。     

Ti~(4+)掺杂对Na-β"-Al_2O_3固体电解质电性能的影响

Na-β"-Al2O3固体电解质材料的Na+电导率直接影响着钠硫电池的性能。以提高Na-β"-Al2O3固体电解质材料Na+电导率为目的,利用传统固相反应法,在Li+掺杂作为稳定剂的基础上,加入0%～1. 25%(质量分数)TiO2引入Ti4+,制备Na-β"-Al2O3固体电解质材料。采用X射线衍射(XRD)以及扫描电子显微镜(SEM)对样品进行表征,采用交流阻抗法测试了样品的电导率。实验结果表明,Ti4+掺杂可较大幅度提高Na-β"-Al2O3材料的Na+电导率,原因有三:一是Ti4+掺杂进入Na-β"-Al2O3晶格取代了Al3+,掺杂后抑制了β"相向β相的转变,从而提高β"相的相对含量,且无杂相生成;二是Ti4+掺杂可以降低材料的烧结温度,促进晶粒生长,从而提高了材料的体积密度;三是Ti4+掺杂可以降低材料在高温烧结过程中钠组分的挥发,提高材料的钠含量。其中,在TiO2掺杂量为0. 75%,烧成温度为1575℃,保温0. 5 h条件下,制得的材料性能最佳,电导活化能为0. 1606 eV,离子电导率由未掺杂样品的0. 023 S·cm-1提升至0. 034 S·cm-1。     

Enhanced photoluminescence in oleic acid modified polyaniline

Polyaniline (PANI) has been of great interest to many researchers because of its high electrical conductivity, environmental stability, ease of preparation, affordability and good redox properties compared to other conducting polymers. It has been reported that PANI doped with orthophosphoric acid exhibits quite high photoluminescence (PL) emission intensity. Orthophosphoric acid doped PANI exhibits good room temperature D.C electrical conductivity also. Thus orthophosphoric acid doped PANI has been found to be a suitable material for optoelectronic applications. In the present work, an attempt is made to develop highly luminescent orthophosphoric acid doped PANI by treating it with oleic acid and it is found that the PL emission intensity is significantly enhanced upon modification of PANI with oleic acid.     

Synthesis of Processable Polyaniline and its Anticorrosion Performance on 316LN Stainless Steel

The soluble polyaniline (PANI) salts were synthesized by chemical-oxidative polymerization of aniline using sodium dodecylbenzene sulfonic acid, camphor sulphonic acid and hydrochloric acid as dopants and ammonium per sulphate (APS) as an oxidant. The synthesized PANI were characterized by X-ray diffraction, scanning electron microscope, Fourier transform-infrared spectroscopy and thermogravimetric analysis. It is found that the yield of PANI, electrical conductivity, solubility and thermal stability varies with the dopants and the stoichiometrics of monomer/dopant ratios. The PANI doped sample follows the solubility order as: PANI–SDBS > PANI–CSA > PANI–HCl. Thermal stability of PANI–CSA is grater than PANI–SDBS and PANI–HCl. XRD pattern shows the higher crystallinity for HCl and CSA doped PANI while SDBS doped PANI shows the poor crystallinity. SEM study revealed the partially crystalline and agglomerated morphology of the polymer. According to the results, the corrosion rate or corrosion current of PANI–SDBS salts coated samples varies with molar ratios of SDBS to aniline and the optimum molar ratio of PANI–SDBS coating to achieve the best anticorrosive performance on 316LN SS is 2.5 mol mol^?1.     

Production and Characterization of PANI/TiO2 Nanocomposites: Anticorrosive Application on 316LN SS

Conductive polyaniline/titanium dioxide (PANI/TiO₂) nanocomposites with different weight ratios were synthesized using in situ chemical oxidative polymerization. PANI/TiO₂ was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis and electrical conductivity. Room temperature conductivities of PANI, PANI/TiO₂ (I), PANI/TiO₂ (II), and PANI/TiO₂ (III) are 9.77 × 10^?4, 1.89 × 10^?5, 2.01 × 10^?5 and 2.87 × 10^?5 S/cm respectively, show decrease of conductivity with increase of TiO₂ content in the nanocomposite due to the hindrance of carrier transport between different conjugated chains of PANI in composite. The IR measurement indicates that there is strong interaction between the PANI and TiO₂ nanoparticles showing beneficial effect on the thermal stability of PANI/TiO₂ nanocomposite. Corrosion inhibition study shows that 316LN stainless steel coated with PANI/TiO₂ nanocomposite with weight ratio 0.05 shows better corrosion inhibition effect than pure PANI and nano-TiO₂ coating.     

镀钨碳纳米管增强铜基复合材料的制备及性能

采用羰基热分解法对多壁碳纳米管表面进行镀钨处理,并以镀钨碳纳米管和电解铜粉为原料,进行机械球磨混粉和放电等离子体烧结,制备了镀钨碳纳米管/铜基复合材料.采用场发射扫描电镜观察了粉体和复合材料的组织形貌,并对复合材料物相进行了X射线衍射分析.探讨了镀钨碳纳米管含量和放电等离子体烧结温度对复合材料致密度、抗拉强度、延伸率和电导率的影响.结果表明,镀钨碳纳米管质量分数为1%和烧结温度为850℃时,复合材料的致密度、抗拉强度和电导率最高.与烧结纯铜相比,复合材料的抗拉强度提高了103.6%,电导率仅降低15.9%.      

Thermal diffusivity measurements in PANI and PANI-MWNT composites using photo acoustic technique

Hydrochloric acid (HCl) doped Polyaniline (PANI) and Polyaniline-Multiwalled Carbon Nano Tube (MWNT) composite samples were synthesized using chemical oxidative polymerization technique. Transmission Electron Microscopy (TEM) and Raman spectroscopy studies clearly establish the formation of PANI (HCl) and PANI (HCl)-MWNT composites. Thermal diffusivity measurements were carried out using Open Photo Acoustic Cell (OPC) technique in transmission configuration and the thermal diffusivity values were calculated. The thermal diffusivity of the composite samples is found to be greater than that of pure PANI. It increases with increase in MWNT loading upto aniline to MWNT feed ratio 1:0.3 and later decreases for the 1:0.5 sample. Still the thermal diffusivity of PANI (HCl)-MWNT composite sample is higher than that of PANI (HCl).The enhancement in thermal diffusivity is due to the high thermal conductivity of MWNT. The decrease in thermal diffusivity of the 1:0.5 sample is explained using dopant induced phonon scattering and thermal interfacial contact resistance. The present study offers ample scope for tailoring the thermal diffusivity parameters of polyaniline composites according to device requirements.     

SYNTHESIS, CHARACTERIZATION AND ENHANCED ELECTRICAL PROPERTIES OF CTAB-DIRECTED POLYANILINE NANOPARTICLES

Inverse microemulsion system of cetyltrimethylammonium bromide (CTAB) molecules is utilized for virtually monodispersed and controlled growth of HC1 polyaniline (PANI) nanoparticles at room temperature (ca. 300 K). The templated electroconductive polymer reveals lamellar crystalline structure under X-ray diffraction signifying marked sub-chain alignment of the polymcrized nanoparticles. The nanostructured polymer has spherically symmetric morphology in a size range of 2.0 nm to 6.0 nm under electron microscope examination. Gel permeation chromatography gives polydispersity index of 1.02 for nanostructured polymer in agreement with the size monodispersity transpired by electron microscopy. The d.c. electrical conductivity σdc of PANI at room temperature is 10.11 S/cm whereas the variation of conductivity with temperature in the range 227-303 K reveals that the conducting mechanism can be considered as three-dimensional ariable-range-hopping (3D-VRH). UV-Vis spectrum indicates two broad absorption bands due to polaron formation that contributes to enhanced electrical conductivity of the polymer. The fundamental bsorption edge in the polymer is formed by direct allowed transitions to the extent that the optical band gap value was found to be 2.35 eV. The crystalline nanostructure and homogeneous doping attained in the cationic template of amphiphile are argued as ontributing factors to the enhanced conductivity of the polymer.     

Novel High Rate Lithium Intercalation Cathode Materials

In recent years,energy storage devices with bothhigh energy and high power densities have been vigor-ously developed for an application to electric vehicles(EVs).The battery properties of ca.2kW·kg-1ofpower density and ca.15Wh·kg-1of energy densityare needed for the EV′s application in the future[1].As the electrode materials are basic elements for thebattery device,the cathode electrodes should have su-perior properties to above expected ones.One ap-proachto develop the cathode materials…     

Electrical conductivity of composite thick films based on powders of doped tin dioxide

Conclusions The electrical conductivity mechanism of doped tin dioxide composite films, which determines their resistivity temperature dependence, is connected with carrier transfer across thin interlayers of a glass phase and has small activation energies characteristic of jump or tunnel conductivity.Translated from Poroshkovaya Metallurgiya, No. 12(264), pp. 65–69, December, 1984.     

改性钢渣/橡胶复合材料导热性能及耐久性研究

利用自制钢渣助磨改性剂处理热闷渣、电炉渣与风淬渣,将改性后的钢渣微粉与炭黑、橡胶基体等复合形成改性钢渣/橡胶复合材料.采用导热系数仪,测定三种改性钢渣/橡胶复合材料热氧老化1、3、5、7、9、11 d的导热系数;根据Young’s与Flory方程计算出三种改性钢渣/橡胶复合材料热氧老化前后的接触角θ与交联密度;采用热重分析仪(TGA)、场发射扫描电镜(SEM)进行热氧老化前后分析.未热氧老化时,在三种改性钢渣/橡胶复合材料中改性电炉钢渣/橡胶复合材料的导热系数最低,为0.187 W·m^-1·K^-1,是因为改性电炉渣粒中位径(d₅₀)最小,即3.49μm,形成更致密的胶裹渣结构,不易形成导热通路,使其导热系数降低.热氧老化时,破坏胶裹渣结构,改性电炉渣/橡胶复合材料形成的孔隙大,分散性最好,降低界面热阻,更易形成导热通路,使其导热系数最高.热氧老化后,橡胶复合材料表面粗糙度变大且存在较长裂纹与较深孔洞,导致橡胶复合材料吸水性增加,接触角下降.由于改性热闷渣的粒径最大,在热作用下氧气更容易进入橡胶复合材料中与橡胶分子链(双键...