Optical,Electrical and Photoresponse Properties of Si-based Diodes with NiO-doped TiO2 Film Prepared by Sol-gel Method

Silicon - The Ti1−xO2NixO films (x = 0.0, 0.05, 0.10 and 0.15) with various NiO contents were prepared by sol-gel technique. The prepared films were coated on n-Si substrate by spin coating...     

表面荷正电聚苯乙烯胶体颗粒界面电性质的研究

以偶氮二异丁脒盐酸盐V50(AIBA)为引发剂[1],水为分散介质,采用无皂乳液聚合法制备聚苯乙烯颗粒,制备出颗粒粒径为500 nm左右单分散性的聚苯乙烯颗粒。研究结果表明:在一定条件下用该方法制备的胶体颗粒zeta电位曲线均出现在平台pH2.0~6.0,说明在一定条件下聚苯乙烯胶体颗粒具有良好的稳定性。     

新型界面助剂的合成及性能研究

设计合成了一类新型界面助剂，对该类助剂的性能进行了研究，估算出了界面助剂的性能参数。结果表明，该类界面助剂能量提高Al(OH)3/环氧对脂复合材料的冲击强度及耐热性能，是一类有效的界面助剂。     

Interfacial Segregation in Perovskites: III, Microstructure and Electrical Properties

A model is proposed to relate segregation of dopants with the development of fine ceramic microstructures and electrical properties in polycrystalline donor-doped BaTiO₃. As the average dopant concentration is increased, the dopant concentration at the grain boundary increases compared with the bulk. This has two important effects: (1) dopant incorporation at the grain boundary shifts from electronic to vacancy compensation and the formation of high-resistive layers, and (2) grain-boundary mobility is impeded and grain growth retarded with increased dopant additions. Thus, for high dopant concentrations, donor-doped BaTiO₃ becomes insulating. The model discusses in detail the nonequilibrium heterogeneous defect chemistry as a function of thermal-processing and accounts for barrier layer phenomena.     

Structural and Interfacial Properties of Hyperbranched-Linear Polymer Surfactant

With oleic acid grafting modification, a series of hyperbranched-linear polymer surfactants (HLPS) were prepared by hydroxyl-terminated hyperbranched polymer (HBP), which was gained through a step synthesis method using trimethylolpropane and AB₂ monomer. The AB₂ monomers were obtained through the Michael addition reaction of methyl acrylate and diethanol amine. The structures of HLPS were characterised by Fourier transform infrared spectrophotometer and nuclear magnetic resonance (NMR), which indicated that HBP was successfully modified by oleic acid. Furthermore, the properties of surface tension and critical micelle concentration of HLPS solution showed that HLPS can significantly reduce the surface tension of water. The morphology of the HLPS solution was characterised by dynamic light scattering, which revealed that HLPS exhibited a nonmonotonic appearance in particle size at different scattering angles owing to the different replaced linear portions. The relationships of the surface pressure to monolayer area and time were measured using the Langmuir–Blodgett instrument, which showed that the surface tension of monolayer molecules increased with the increasing of hydrophobic groups. In addition, the interface conditions of different replaced HLPS solutions were simulated.     

氟橡胶胶层/乙烯丙烯酸酯橡胶胶层复合结构胶管的开发及脉冲性能评价

基于乙烯丙烯酸酯橡胶（AEM）VMX5315的耐高温性能,开发了氟橡胶（FKM）胶层/AEM胶层复合结构胶 管（以下简称FKM/AEM结构胶管,其余类同）,并测试其脉冲性能。结果表明,FKM内胶层可以保护其余胶层免受热氧的攻击,FKM/AEM（VMX5315/Ultra HT）结构胶管具有更好的耐热性能,与FKM/甲基乙烯基硅橡胶（VMQ）和氟硅橡胶（FVMQ）/VMQ结构胶管相比具有更好的粘合性能和更低的成本,FKM和AEM VMX5315是涡轮增压发动机高温中冷进气管的优选材料。     

Structural,Morphological, Optical,and Electrical Properties of PANi-ZnO Nanocomposites

Thin films of polyaniline (PANi) and PANi–Zinc oxide (ZnO) nanocomposites have been synthesized by a spin-coating technique. The ZnO powder of particle size 50–60 nm was synthesized by sol–gel technique and the polyaniline was synthesized by chemical oxidative polymerization of aniline. The nanocomposite films were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), UV–Vis spectroscopy, and four probe technique, and the results were compared with polyaniline films.     

Synthesis of Novel (Polymer Blend-Ceramics) Nanocomposites: Structural,Optical and Electrical Properties for Humidity Sensors

Fabrication of novel nanocomposites films of (PVA–CMC) blend and (PVA–CMC) blend doped by niobium carbide nanoparticles has been investigated. The structural, optical and electrical properties of (PVA–CMC–NbC) nanocomposites for humidity sensors have been studied. The (PVA–CMC–NbC) nanocomposites were prepared with different concentrations of (polyvinyl alcohol and carboxyl methyl cellulose) and Niobium carbide nanoparticles. The experimental results of optical properties for (PVA–CMC–NbC) nanocomposites showed that the absorbance, absorption coefficient, extinction coefficient, refractive index, real and imaginary dielectric constants and optical conductivity of (PVA–CMC) blend increase with increase in Niobium carbide nanoparticles concentrations. The transmittance and energy band gap decrease with increase in Niobium carbide nanoparticles concentrations. The DC electrical properties of (PVA–CMC–NbC) nanocomposites showed that the electrical conductivity of the blend increases with increase in NbC nanoparticles concentrations. The experimental results of novel (PVA–CMC–NbC) nanocomposites applications showed that the (PVA–CMC–NbC) nanocomposites have high sensitivity for relative humidity.     

Carbon Nanotube Reinforced Alumina-Based Ceramics with Novel Mechanical, Electrical, and Thermal Properties

The extraordinary mechanical, thermal, and electrical properties of single-wall carbon nanotubes (SWCNT) have prompted the development of advanced engineering materials with improved properties through the incorporation of carbon nanotubes in selected matrices. Dense SWCNT reinforced alumina nanocomposites have been fabricated by novel spark-plasma-sintering (SPS) technique. SWCNT were also successfully used to convert insulating nanoceramics to metallically conductive composites. Additionally, novel anisotropic thermal properties have been observed in the carbon nanotube composites. Such multifunctional carbon nanotube/ceramic composites with improved mechanical and electrical properties along with anisotropic thermal properties are envisaged for a wide range of applications.     

Electrical and Interfacial Properties of an Antipyrine Derivative/p-Si Heterojunction

Electrical properties of a Au/N-(5-{cyano-[(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-hydrazono]-methyl}-[1,3,4]thiadiazol-2-yl)-benzamide (ACTB)/p-Si/Al heterojunction have been investigated by using current-voltage (I-V) and capacitance-voltage (C-V) measurements. At forward voltages V≤0.36 volt, thermionic emission theory was used to determine the ideality factor and zero-bias barrier height of the device. Although, the device is found to be nonideal in showing an ideality factor of 1.84, it is found to have a modified barrier height value (0.71 eV) compared to a conventional Au/p-Si contact. Cheung functions were used to obtain the barrier height, series resistance and ideality factor of the diode. The current is found to be controlled by the space charge limited current (SCLC) dominated by exponential trap distribution in the voltage range 0.36<V≤1.56 and SCLC dominated by a single trap in the voltage range 1.56<V ≤2. The I-V characteristics in the reverse direction are analyzed in terms of Poole–Frenkel and Schottky mechanisms. C-V characteristics show that the junction is of an abrupt nature in which the built-in potential, barrier height and charge carrier concentration are estimated. Based on combined I-V and C-V characteristics, the interface state density of the heterojunction has also been calculated. The ACTB film can be used in the device modification applications of the conventional Au/p-Si diodes.     

一种新型聚合物电解质中离子传递及界面性质研究

合成了聚（甲基丙烯酸甲酯-丙烯腈-甲基丙烯酸锂）（简记为PMAML）聚合物基质材料，以PMAML和聚偏氟 乙烯混合物为基质制备了新型复合聚合物电解质，其中增塑剂为碳酸乙烯酯和碳酸二甲酯，锂盐是LiBF4。用刮刀 在玻璃板上涂膜得到取合物膜，把聚合物基质膜在电解质溶液中浸渍后成为聚合物电解质膜。采用限制扩散方法测 试了电解质中离子的扩散系数，由稳态极化法测得了迁移数。所制聚合物电解质中锂离子的扩散系数和迁移数分别为 2.67×10-7cm2·s-1和0.53。通过交流阻抗技术研究了聚合物电解质与电极间界面性质，Li/GPE/Li的界面阻抗随放置 时间延长而增大，Li/GPE/MPCF的界面阻抗随电极的电位降低而减小。组装了聚合物电解质锂离子电池，测试结果表 明，该聚合物电解质具有较好的离子传输性质和电化学性能，能用作锂离子电池的电解质。     

季铵盐型有机硅双子表面活性剂的合成与界面性能

以八甲基环四硅氧烷(D4)和1,1,3,3-四甲基二硅氧烷(HMM)为原料,合成双氢封端的聚二甲基硅氧烷(HPDMS);以烯丙基聚氧乙烯醚(APEG)和环氧氯丙烷为原料,合成烯丙基聚氧乙烯氯醇醚(APECAE),然后将其与十八烷基二甲基叔胺进行阳离子化,制得季铵盐型烯丙基聚氧乙烯氯醇醚(QASAAE);在铂催化剂作用下,HPDMS与QASAAE进行硅氢化加成反应制得季铵盐型有机硅双子表面活性剂(Gemini-QASPSS)。用IR和1HNMR对目标产物(Gemini-QASPSS)的结构进行了表征,并且通过测定其水溶液的平衡表面张力研究了其表面活性。结果表明,在临界胶束浓度为5.3×10-5mol/L时,可以将水的表面张力降至24.5 mN/m;饱和吸附量、饱和吸附层中每个Gemini-QASPSS分子所占的平均面积和形成胶束的标准自由能分别为1.6×10-6mol/m2、1.08 nm2和-28.6 kJ/mol。     

新型含偶氮苯结构线型聚酯的合成及性能

采用熔融聚合法反应得到3种新型侧链含偶氮苯结构的线型聚酯(P1-P3),通过IR、UV-vis、1H NMR、SEC、TG-DTA和荧光等对聚酯的结构和性能进行了表征。聚酯(P1-P3)在氯仿、四氢呋喃等常用有机溶剂中有良好的溶解性,Mw分别为31 890、20 165、29 655 g/mol,5%失重温度分别为332、322、312℃。在365 nm紫外光照射下,聚酯(P1-P3)中的偶氮苯结构发生了反-顺异构化。聚酯(P1-P3)发紫色荧光。     

3,4,5-三氟-2-甲基苯类液晶化合物的合成与性能

以3,4,5-三氟苯酚、3,5-二氟-4'-烷基联苯为原料,经酚羟基保护反应、丁基锂/碘甲烷上甲基反应、Williamson醚化反应等5步反应最终合成4-[二氟(3,4,5-三氟-2-甲基-苯氧基)甲基]-3,5-二氟-4'-烷基联苯类化合物。纯化后目标产物的气相色谱纯度≥99.5%,总收率约为47%,结构经~1HNMR及GC-MS确证。其中,合成2-(3,4,5-三氟-2-甲基-苯氧基)四氢吡喃适宜的物质的量比为n(2-(3,4,5-三氟苯氧基)四氢吡喃)∶n(丁基锂)=1∶1.2,3,4,5-三氟-2-甲基苯酚和4-溴二氟甲基-3,5-二氟-4'-烷基联苯醚化反应的最优化条件为在DMSO中反应4 h。将该化合物添加到液晶的基础配方中,能降低旋转粘度(γ1),提高液晶的响应速度,增加介电各向异性(Δε),降低阈值电压。     

新型席夫碱的合成及光学性质研究

以4,4＇-二氨基联苯和3-氰基苯甲醛为原料,冰醋酸作催化剂,在乙醇中反应得到一种新型的双席夫碱化合物,经核磁共振、红外光谱和元素分析表征,产物为4,4’-二[（3-氰基苯基）亚甲胺基]联苯,对其紫外吸收和荧光光谱性质进行了研究。     

一种杂多酸多氮化合物的合成及性质研究

以有机配体1,4-二(1,2,4-三唑-1-甲基)苯、磷钼酸为原料,采用水热法合成了一种杂多酸多氮化合物1。通过x-单晶衍射测定了化合物的结构。研究了该化合物对染料亚甲基蓝的吸附作用,当亚甲基蓝的浓度为5 mg/L时,25 mg化合物的平衡吸附容量qe为4.88 mg/g,去除率达到98%,吸附的动力学研究表明为二级动力学,吸附机理为henry型吸附模型。     

有机/无机酸复合掺杂导电聚苯胺的合成及性能研究

采用化学氧化聚合法以苯胺为单体,过硫酸胺为氧化剂,在有机/无机混合酸的水溶液中合成导电聚苯胺.考察了有机/无机混合酸对聚苯胺性能的影响,并通过四探针、差热分析、红外光谱及拉曼光谱研究聚苯胺掺杂前后结构的变化.结果表明,当聚合温度为20℃、磺基水杨酸和硫酸的摩尔浓度比为0.25:1时,掺杂态聚苯胺电导率和溶解度达到最大值;其中电导率可达13.5 S·cm~(-1),在氮甲基吡咯烷酮(NMP)中溶解度可达85%.差热分析表明,有机/无机酸复合掺杂聚苯胺热稳定性较单一酸掺杂聚苯胺热稳定性有很大的提高;红外光谱和拉曼光谱表明;掺杂后聚苯胺具有导电性是因为其分子链上电荷离域形成了共轭结构.     

Some Structural and Electrical Properties of Lithium Silicate Glasses

Dielectric measurements, analyzed in terms of the Maxwell-Wagner-Sillars theories of inhomogeneous dielectrics, have been used to investigate the phase-separation characteristics of various lithium silicate glasses. Such measurements are shown to provide evidence of the continuous or discontinuous nature of separated phases and to allow estimates of their shape factors and concentrations. The results indicate that dielectric measurements are particularly useful in following phase-separation processes in glasses from the initial to the final stages.     

Structural,Electrical and Optical Properties of PVC/ZnTe Nanocomposite Thin Films

Journal of Inorganic and Organometallic Polymers and Materials - ZnTe nanoparticles (NPs) were synthesized using hydrothermal method and then were dispersed in poly(vinyl-chloride) (PVC) to prepare...     

Electrical Properties of MOS Capacitor with TiO2/SiO2 Dielectric Layer

Silicon - The TiO2/SiO2 film being the dielectric layer was grown on the n-Si wafer using radio frequency (RF) magnetron sputtering. Thus, the Au/TiO2/SiO2/n-Si metal-oxide-semiconductor (MOS)...