基于灰色理论的掺杂态导电聚苯胺的制备及导电性能研究

以苯胺(An)为单体,氨基磺酸(SA)为掺杂剂,过硫酸铵(APS)为氧化剂,采用化学氧化聚合法合成了掺杂态导电聚苯胺。考察了n(苯胺)/n(掺杂剂)、n(苯胺)/n(氧化剂)和反应时间对聚苯胺电导率的影响。结果表明,当n(An)∶n(SA)∶n(APS)=1∶6∶0.4、反应时间为6h时,聚苯胺的电导率最高达到0.87S/cm。进一步利用灰色关联分析,定量地分析了各因素对掺杂态导电聚苯胺电导率的影响程度,得出了各因素影响电导率的大小顺序为掺杂剂、氧化剂、反应时间。并以氨基磺酸的添加量为基本建立了掺杂态导电聚苯胺电导率的灰色预测模型(灰色离散Verhulst模型),预测了氨基磺酸不同添加量下的电导率,平均预测精度为97.25%。结果证明,灰色系统理论在掺杂态导电聚苯胺的电导率的预测中是可行的。     

功能磺酸掺杂聚苯胺的电导率及其光谱特征研究

合成了十二烷基苯磺酸(DBSA)、磺基水杨酸(SSA)和对甲苯磺酸(TSA)掺杂的导电聚苯胺样品:PANI/DBSA,PANI/SSA,PANI/TSA.用四探针法测定其电导率,研究不同功能磺酸掺杂对聚苯胺电导率的影响,分析它们的FT-IR光谱、UV-VIS光谱吸收及NIR光谱反射现象及其变化.结果表明,功能磺酸掺杂剂的对阴离子尺寸大小影响其掺杂PANI的电导率和光谱特征,PANI/DBSA的对阴离子尺寸大于PANI/SSA,PANI/TSA,其电导率、FT-IR和UV-VIS图谱红移量都相对PANI/SSA,PANI/TSA大.同时不同功能磺酸掺杂聚苯胺的NIR光谱反射率为:PANI/DBSA＞PANI/SSA＞PANI/TSA.     

掺杂态聚苯胺的XPS研究

对经不同质子酸盐酸 (HCl)、对甲基苯磺酸 (TSA)及磺基水杨酸 (SSA)掺杂的聚苯胺 (PAn)进行 3h空气浴的热处理 ,并用电导率和 XPS对其进行了表征。结果表明 ,PAn·HCl在 16 0℃时其电导率下降了六个数量级 ,其表面掺杂率随温度的升高而降低 ,并且具有不同结合能 Cl的相对组成也随之发生了变化 ;PAn·TSA及 PAn·SSA在 2 0 0℃的电导率分别下降了两个和一个数量级 ,但其表面掺杂率未发生明显的变化。随着温度的升高 ,掺杂态 PAn膜的脆性和表面氧化的程度增加     

聚苯胺网状纳米结构的合成与表征

以樟脑磺酸为掺杂剂、三氯化铁和过硫酸铵为二元混合氧化剂,在水溶液体系中通过苯胺原位聚合制备得到直径为80～100nm的聚苯胺网状纳米结构,其导电率为10-2～10-1S/cm.进一步研究结果表明,三氯化铁可抑制聚苯胺纤维的形成,并同时起到掺杂剂和氧化剂的双重作用;通过控制FeCl3用量和n(APS):n(FeCl3)的比值,可调节产物的形貌结构和导电率.     

聚苯胺包覆镍纤维的制备及电性能研究

镍纤维经预处理后,采用化学氧化法对其进行包覆改性,制备聚苯胺包覆改性镍纤维,以改善镍纤维的电性能。主要探究了掺杂剂种类、浓度、镍纤维长径比以及搅拌速率等因素对聚苯胺包覆镍纤维效果的影响,利用核磁共振、能谱仪和扫描电镜对产物进行元素和形貌分析,采用四探针电阻率测试仪测试聚苯胺包覆镍纤维的电性能。结果表明:以0.1mol/L盐酸为掺杂剂,将长径比为8mm的镍纤维在0～5℃下以60r/min的转速聚合得到聚苯胺包覆镍纤维材料,其包覆层致密均匀,且得到最大的电导率,其值为2.62×103S/cm。     

聚苯胺/聚乙烯醇纳米纤维的制备与表征

以十二烷基苯磺酸(DBSA)为表面活性剂和掺杂剂,通过乳液聚合的方法制备聚苯胺/聚乙烯醇(PANI/PVA)复合乳液用于静电纺丝,制备出超细复合纤维毡,通过SEM、XRD和力学测试表征PANI/PVA超细复合纤维毡的外观形貌、纤维直径、结晶度及其力学性能。结果表明:有机磺酸掺杂后的聚苯胺导电性能达到1.28S/cm;1459cm-1处醌环和苯环上的C=C伸缩振荡峰和1697cm-1处醌环上C=N伸缩振荡峰的聚苯胺特征峰明显;YG006型电子单纤维强力机的测试发现,PANI/PVA纤维集合体的面密度对其力学性能的影响显著;当纺丝工艺条件设定为接收距离18cm、电压24kV时,PANI/PVA纤维直径达到600nm,直径分布小于150nm,PANI微颗粒分散于PVA纤维基体表面。     

导电聚苯胺纤维的制备与性能表征

以一种新型的双子表面活性剂6,6′-(丁基-1,4-二基双氧)双(3-壬基苯磺酸)(9BA-4-9BA)作为掺杂剂制备聚苯胺导电纤维,并与用2-丙烯酰胺基-2-甲基丙磺酸(AMPSA)掺杂的聚苯胺纤维的性能进行比较,探讨了聚苯胺分子量、纺丝原液的浓度、掺杂剂种类、凝固浴、牵伸工艺对纤维形貌和导电性能的影响。研究表明,质量分数为14%的AMPSA掺杂聚苯胺的二氯乙酸溶液在丙酮凝固浴中得到的初生纤维的电导率达到1.77S/cm,而质量分数为14%9BA-4-9BA掺杂聚苯胺的二氯乙酸溶液在9BA-4-9BA/丙酮凝固浴中得到的初生纤维及1倍牵伸纤维的表面形貌光滑规整,电导率分别为0.39 S/cm和1.14 S/cm。     

热处理对聚苯胺导电性及其介电性能的影响

采用苯胺化学氧化聚合制得盐酸掺杂态聚苯胺(PANI-HCl),考察了导电率以及介电常数随热处理温度的变化,并通过FT-IR、TGA、DSC和XRD等测试手段研究了空气气氛中不同热处理温度对PANI-HCl的掺杂程度以及微观结构的影响.结果表明:PANI-HCl在低于100℃的热处理保持优异的电导率和介电常数,电导率的数量级在100,介电损耗角正切tgδε≈0.35～0.49,当温度上升至160℃,电导率数量级下降到10-7,tgδε在0.1以下,其原因是由于热处理对掺杂态聚苯胺进行了脱掺杂,而且改变了聚苯胺的微观结构.     

乳液聚合法制备有机改性高岭土/聚苯胺复合材料及其性能研究

以十六烷基三甲基溴化铵为有机化改性试剂,对高岭土进行改性,再以苯胺为单体,十二烷基苯磺酸为掺杂剂与乳化剂,过硫酸铵为引发剂,采用乳液聚合法制备有机改性高岭土/聚苯胺复合材料。结果表明,利用四探针技术测试发现,随着有机改性高岭土掺量的增加,复合材料电导率逐渐下降;FT-IR分析证明采用乳液聚合法可实现高岭土有机化改性及其与聚苯胺原位复合;TGA分析结果表明,复合材料耐热性能随改性高岭土引入量的增加而逐渐增强,当掺量为50%(质量分数)时,聚苯胺的分解起始温度和失重最快温度分别提高了13℃和36℃;采用SEM分析证明二者复合成功;XRD分析说明改性高岭土与聚苯胺的复合仅通过物理吸附作用而未发生插层。     

用溶胶-凝胶法制备的纳米 TiO_2粉末的结构

本文采用溶胶-凝胶法制备出纳米 TiO_(2)粉末,并通过热重分析(TG)、差示扫描量热分析(DSC)、X 射线衍射(XRD)、透射电镜(TEM)等实验手段研究了其微观结构及形貌随着热处理温度(T_a)变化的规律。当热处理温度低于500℃时,TiO_2粉末的平均晶粒和颗粒尺寸均小于20nm,所有晶粒均为锐钛矿结构。当热处理温度高于550℃时,TiO_2颗粒及晶粒迅速长大,并且样品中开始出现金红石结构的TiO_2晶粒。当热处理温度高于800℃时,样品中所有晶粒均为金红石结构。     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

Mechanism Study on the Wear of CrAlTiN Coated High-Speed Steel Twist Drills Under Dry Cutting Conditions

As demands about environment protection are growing up, dry cutting technology is getting more and more concerns from all over the world. Main works performed here are study on dry cutting performances and wear mechanisms of M2high-speed steel (HSS) twist drills with CrAlTiN multicomponent coatings, which was deposited using magnetron sputter ion plating system, in drilling 45 and 30CrMnSiA steel, and their comparisons to those in drilling the same steel but using monolayer CrN and commercial TiN coated drills. Drilling performances of drills are evaluated mainly through the measurements of width on outer corner flank land and the cutting forces. Results show that performances of CrAlTiN coated drills are better than those of monolayer CrN and TiN coated drills. In drilling 45 and 30CrMnSiA steel, the average tool life of the CrAlTiN coated drills are 17.2 and 11.8 times higher than those of the uncoated drills. Observing wear of the drill with scanning electronic microscope, results show that there is no crack or spallation of the CrAlTiN coatings in wear zones. Main mechanism of the wear here is adhesion.     

Study on Bond Ability of Arc-Spraying Coatings with Different Surface Pretreatment on Cast-Iron

Arc spraying coatings are widely used in various applications, but uncommon in cast iron substrate. Different surface pretreatment technology is tested on substrates of gray cast iron. Surface roughness and residual stress were measured by TR200 and X-ray diffraction analyzer. Influence of different surface pretreatment methods ( dry blasting and fusebond) on roughness and residual stress was analyzed. The arc-sprayed coatings of wire 3Cr13 (φ2mm) on gray cast iron substrate is studied. The microstructure and interface of bonding layer were observed by SEM. The bond strength was taken by tensile test. Results show that bond strength with grit blasting is higher than fuse-bond; it is feasible to make wire 3Cr13 coating with arc spraying on cast iron substrate roughened by grit blasting.     

Structural Characteristics of TiO2 Ceramic Coating by Micro-Plasma Oxidation

TiO2 ceramic coatings with thickness of 20 μm were formed on the surface of pure titanium by micro-plasma oxidation. Their micro-structures were investigated by by using X-ray diffraction and their surface images were detected by using scan electronic microscope. There were three kinds of TiO2 coatings, pure anatase type TiO2 phase, mixed phases consisted of rutile type TiO2 phase and anatase type TiO2 phase, pure rutile type TiO2 phase. The coating surface with the pure anatase type TiO2 phase is rough, while the coating surface with the pure rutile type TiO2phase is smooth. The upper coating surface with the mixed type TiO2 phases is anatase type TiO2 structure and the subsurface of the TiO2 coating is rutile type TiO2structure.     

Evaluation of fatigue life of steel using steel grain size

The insightful discussion of the relationship between the construction of metallographic and fatigue life and proposition of mathematical relationships describing this relationship was conducted in the paper. This paper presents a method for estimating the fatigue life, based on the construction of the microstructural material taking into account the grain size and the participation of ferrite and pearlite phase.