基于铝与铬菁R显色体系对水溶液中C_2O_4~(2-)的识别与检测

建立了一种以铝与铬菁R为显色体系,选择性识别检测水中草酸根离子的新方法。在烷基三甲铵类阳离子表面活性剂的存在下,当向Al3+与铬菁R形成的蓝色配合物显色液中加入草酸根离子时,由于竞争取代,草酸根离子与Al3+形成无色配合物,溶液颜色由蓝色变为铬菁R自身的红色,吸收光谱也发生明显变化,其他如Cl-、Ac-、SO2-4、NO-3等常见阴离子则均未引起明显的光谱及溶液颜色变化,从而实现了对C_2O_4~(2-)的裸眼识别。且草酸根浓度在0.4×10-5~2.0×10-5mol/L范围内,浓度与吸光度符合朗伯比尔定律,实现了对水溶液中草酸根的快速检测。     

氯化铬和氯化镍浓度及其存在形式对ChCl-EG低共熔溶剂电导率的影响

研究了氯化铬(CrCl_3·6H_2O)和氯化镍(NiCl_2·6H_2O)浓度和存在形式对氯化胆碱-乙二醇(ChCl-EG)低共熔溶剂的黏度和电导率的影响。电喷雾质谱(ESI-MS)分析结果表明,在溶解有CrCl_3?6H_2O和NiCl_2?6H_2O的ChCl-EG(ChCl-EG-NiCl_2·6H_2O-CrCl_3·6H_2O)溶液中出现了配阴离子[Cr(H_2O)_2Cl_4]~–和[Ni(H_2O)_2Cl_4]~(2-)。由此可以推断,Cr~(3+)(或Ni~(2+))的两个d轨道、4s和4p轨道发生d~2sp~3杂化,形成6个等同的杂化轨道,接受6个配体(Cl~-和H_2O)形成阴离子配合物。该溶液的电导率随温度的升高而增大,随总金属离子浓度的增大而减小。此外,溶液黏度随温度和总金属离子浓度的变化趋势与电导率相反。这主要是由于镍和铬配离子的形成改变了溶液中的离子组成。     

40℃和75℃下三元体系NH4HCO3-NH4VO3-H2O中NH4VO3溶解度的测定

针对钾系亚熔盐法钒渣钒铬共提清洁生产工艺的中间产品钒酸钙,提出通过碳化铵化/冷却结晶将钒酸钙转化为钒氧化物产品的新方法。分别研究了NH4HCO3-NH4VO3-H2O三元体系在碳化反应温度(75℃)和结晶沉钒温度(40℃)时NH4VO3的溶解度,得到了此时NH4VO3的溶解度数据。40℃时,NH4VO3溶解度随NH4HCO3浓度升高而降低。75℃时,NH4VO3溶解度则随NH4HCO3浓度升高呈U形变化。通过对比两个温度下NH4VO3的溶解度曲线,验证了碳化铵化工艺75℃反应、40℃结晶的设计思路。并经过理论计算,得到NH4VO3的理论一次结晶率为92.71%。再由得到理论结晶率时的反应和结晶NH4HCO3浓度,优化了钾系亚熔盐法钒渣钒铬共提清洁生产工艺中钒转化单元的工艺路线,绘制了工艺原则流程图。     

纳米TiO_2膜电极上乙醛酸的电催化合成研究

运用电化学循环伏安法 (CV)对纳米TiO2 膜电极 (Ti/nano TiO2 )在硫酸和草酸溶液中的电化学行为进行了研究。在c(H2 SO4 ) =1mol/L溶液中的循环伏安图上Epac1=- 0 .5 6V(vs.SCE)和Epac2 =- 0 96V(vs.SCE)处 ,出现两对可逆氧化还原峰 ,而在相同扫描速度下草酸溶液中的循环伏安曲线上 ,这两对电极反应氧化峰基本消失 ,还原峰电流增大 ,表明Ti/nano TiO2 膜电极对电还原草酸成为乙醛酸的反应具有较高的电催化活性和选择性。常温常压下 ,控制电位Epc=- 1 0V左右电解合成乙醛酸 ,乙醛酸的产率和电流效率分别达到 96 5 %和 90 %。     

应用于氧化还原电池正极的VO(CH_3SO_3)_2电解液

以甲基磺酸为溶剂,制备了用于氧化还原电池正极的钒电解液,并对不同自由酸浓度的电解液进行了电导率、粘度和热稳定性、电化学性能测试。结果表明,当CH3SO3H的浓度为2 mol/L时,电解液的导电性最好;随着CH3SO3H浓度的升高,电解液的粘度逐渐增大,钒离子的扩散系数逐渐降低。当自由酸的浓度为4 mol/L时,电解液具有良好的稳定性,电极过程的可逆性最好。以2 mol/L VO(CH3SO3)2+4 mol/L CH3SO3H为正极电解液组装的锌钒电池,充电以后的开路电压达1.96 V,前10个循环的放电平均中值电压为1.61 V,平均电流效率为96.12%,能量效率为74.03%。     

应用于氧化还原电池正极的VO(CH_3SO_3)_2电解液

以甲基磺酸为溶剂,制备了用于氧化还原电池正极的钒电解液,并对不同自由酸浓度的电解液进行了电导率、粘度和热稳定性、电化学性能测试。结果表明,当CH3SO3H的浓度为2 mol/L时,电解液的导电性最好;随着CH3SO3H浓度的升高,电解液的粘度逐渐增大,钒离子的扩散系数逐渐降低。当自由酸的浓度为4 mol/L时,电解液具有良好的稳定性,电极过程的可逆性最好。以2 mol/L VO(CH3SO3)2+4 mol/L CH3SO3H为正极电解液组装的锌钒电池,充电以后的开路电压达1.96 V,前10个循环的放电平均中值电压为1.61 V,平均电流效率为96.12%,能量效率为74.03%。     

不同电解质溶液及其离子浓度和pH值对改性微滤膜流动电势的影响(英文)

采用商品级α-Al2O3微滤膜.由均质共沉淀法制备了TiO2改性α-Al2O3微滤膜.研究了不同的电解质溶液、溶液的离子浓度和pH值对TiO2 改性的α-Al2O3微滤膜流动电势的影响规律.结果表明:对于NaCl溶液,膜流动电势随溶液离子浓度的增大向降低,其等电点在4.3左右:随着溶液的pH值由3增加到10.膜流动电势由值逐渐变为负值.而对于FeSO4,CaSO4,Na2SO4,NaCl和CaCl2溶液,当溶液的离子浓度固定时,膜流动 电势则随溶液的电导率的增加而降低.     

纳米α-Fe_2O_3/草酸体系对甲基橙的异相光催化降解研究

以纳米α-Fe2O3和草酸在500 W汞灯照射下构成了光化学类Fenton体系,并研究在此体系中甲基橙溶液的异相光催化降解行为。考察了草酸的初始浓度对纳米α-Fe2O3和光催化体系对甲基橙催化反应效率的影响,同时为探究该光催化反应过程的机理,对反应过程中溶液p H、Fe2+的浓度进行了检测。结果表明,草酸能显著促进甲基橙的脱色与降解,甲基橙光化学降解反应一级动力学常数随草酸浓度的增大呈先升后降的趋势,最佳草酸初始浓度为1 mmol/L;溶液p H的变化也显著影响甲基橙的脱色。光化学反应过程中溶液p H和Fe2+的浓度的变化和草酸的初始浓度有关。     

磷钒酸盐红色发光粉的制备及性能研究

采用燃烧法合成了一种近紫外激发的Ca3((P,V)O4)2:Eu3+发光材料,用X射线衍射谱、荧光光谱对样品进行了表征。结果表明,荧光粉基质Ca3((P,V)O4)2具有畸变的Ca3(VO4)2的结构,VO34-取代了部分的PO34-,但Ca2+的半径与Eu3+接近,因此Eu3+容易进入晶格,表现出良好的发光性能。荧光光谱分析发现荧光粉可被376 nm紫外光激发,主发射峰值位于620 nm(Eu3+离子的5D0→7F2跃迁)的红光,同时详细研究了Eu3+离子掺杂浓度、引发温度及尿素用量对荧光粉发光性能的影响。     

氯化铬和氯化镍浓度及其存在形式对ChCl-EG低共熔溶剂电导率的影响

研究了氯化铬(CrCl₃·6H₂O)和氯化镍(NiCl₂·6H₂O)浓度和存在形式对氯化胆碱-乙二醇(ChCl-EG)低共熔溶剂的黏度和电导率的影响。电喷雾质谱(ESI-MS)分析结果表明,在溶解有CrCl₃?6H₂O和NiCl₂?6H₂O 的ChCl-EG(ChCl-EG-NiCl₂·6H₂O-CrCl₃·6H₂O)溶液中出现了配阴离子[Cr(H₂O)₂Cl₄]^–和[Ni(H₂O)₂Cl₄]^2-。由此可以推断,Cr³⁺(或Ni²⁺)的两个d轨道、4s 和4p轨道发生d²sp³杂化,形成6个等同的杂化轨道,接受6个配体(Cl^-和H₂O)形成阴离子配合物。该溶液的电导率随温度的升高而增大,随总金属离子浓度的增大而减小。此外,溶液黏度随温度和总金属离子浓度的变化趋势与电导率相反。这主要是由于镍和铬配离子的形成改变了溶液中的离子组成。     

石煤氯化钠焙烧水浸液纳滤提钒过程

采用石煤氯化钠焙烧浸出液为原料,研究了驱动压力、料液pH值及钒浓度对钒纳滤浓缩效果的影响,并考察了Cl-在纳滤过程中的行为. 结果表明,在驱动压力10.0~12.5 kg/cm2和pH值5.16~6.15的优化条件下,料液中的钒(V2O5)可纳滤浓缩到35 g/L以上. pH值6.15时,钒的截留率最高,达92%. 浓缩液按沉钒化学计量的2.2倍加入NH4Cl,沉淀得到的NH4VO3经500℃煅烧1 h得到的V2O5产品纯度为98.6%.     

Calcium zirconate: preparation, properties and application to the solid oxide galvanic cells

Stoichiometric, and doped with a small amount of CaO, calcium zirconate dense samples were prepared. X-ray analysis revealed that the solid solution was formed in the concentration range up to x=0.06 in the {xCaO+(1−x)CaZrO₃} mixture. The activity of CaO in the solid solution was determined by the emf method at the temperatures 1073 and 1273 K. The electrical conductivity was measured using both dc four-probe and ac impedance spectroscopy methods. The maximum conductivity values were observed for the sample with x=0.06. This sample was used for further investigation. The oxygen-ion transference number, estimated by the emf method, appeared to be close to unity. The partial electronic (electron and electron hole) conductivities, deduced from current–potential curves following the polarisation method, were found to be very small with respect to total electrical conductivity. Then, the sample was tested as an electrolyte in solid oxide galvanic cells. In this way, the values of the standard free enthalpy of formation of cobalt and nickel silicates at the temperatures 1073 and 1273 K were determined and compared with those obtained by other authors.     

SDBS辅助合成Y2O3/Ag3VO4光催化剂及其催化可见光降解罗丹明B

以V2O5, AgNO3和Y(NO3)3×6H2O为原料、十二烷基苯磺酸钠为辅助剂,采用直接沉淀法和浸渍法制备单斜晶相Ag3VO4和Y2O3/Ag3VO4复合催化剂,表征了产物的结构和形貌,并分析了其形成机理;在可见光下研究了其催化可见光降解罗丹明B(RhB)的性能. 结果表明,所得Y2O3/Ag3VO4复合催化剂吸收边相对纯相Ag3VO4发生红移,禁带宽度减小至1.83 eV,电子-空穴对复合几率降低,对RhB有较好的可见光催化活性和稳定性,可见光照射15 min后,0.08 g 3% Y2O3/Ag3VO4催化200 mL 8 mg/L RhB溶液的降解率达94.2%.     

Kinetic studies of the aqueous oxidative polymerization of 3-hydroxyaniline and characterization of the polymer obtained

The aqueous polymerization of 3-hydroxyaniline (3HA) was studied using sodium dichromate as oxidant in presence of hydrochloric acid. The effect of hydrochloric acid, sodium dichromate and monomer concentration on the polymerization rate, specific viscosity of the obtained polymer and a.c.conductivity was investigated. The initial and overall reaction rates increase with the increase in hydrochloric acid concentration or sodium dichromate concentration but decrease with the increase in the monomer concentration. The specific viscosity values increase with increasing of hydrochloric acid concentration or monomer concentration which means that the molecular weight of the polymer samples increases in the same direction. But the molecular weight decreases with increasing sodium dichromate concentration. The highest a.c. conductivity value of the obtained polymer was found in case of using 0.0019 g mol/L of Na 2 Cr 2 O 7 , 0.1 M HCl and 0.1 M monomer solution in the reaction medium. Some electrical properties of this sample were investigated as a function of temperature. The order of the polymerization reaction with respect to hydrochloric acid, Na 2 Cr 2 O 7 and monomer concentration was found to be 1.13, 1.2 and m 0.909 respectively. The apparent activation energy (E a ) for this polymerization system was found to be 6.1248 2 10 4 J/mol. The obtained poly(3-hydroxyaniline) was characterized by UV-visible, IR spectroscopy, X-ray diffraction analysis and electron microscopy studies. The thermogravimetric analysis (TGA) and differential thermal analysis (DTA) results were used to confirm the structure.     

基于BP神经网络的脉冲放电等离子体氧化酸性橙Ⅱ影响因素分析

为了说明多针-板电极脉冲放电等离子体(PDP)氧化酸性橙Ⅱ(AO7)过程中多种因素对AO7脱色效果的影响,本研究建立了PDP氧化AO7的BP神经网络模型,用BP神经网络模拟多因素作用下PDP氧化AO7的反应过程,重点考察溶液条件,包括溶液初始浓度、初始电导率和初始pH等条件对AO7脱色效果的影响趋势。研究所建立的BP神经网络模型对AO7脱色效率的预测值与实际测定值的偏差在±5%范围内,说明BP神经网络模型可以很好地分析PDP这一复杂体系中各溶液条件对AO7脱色效率影响的规律。模型分析结果表明:所建立的PDP水处理系统中,在一定的AO7溶液初始浓度条件下有较高的脱色效果;溶液电导率对AO7的脱色效果基本没有影响;酸性条件更有利于AO7的脱色。     

基于ERT技术的硫酸钡颗粒形成过程研究

采用电阻层析成像技术（ERT）实时监测反应器内横截面电导率变化,进而考查络合法形成球形硫酸钡颗粒的过程中溶液电导率变化趋势。在拟均相条件下,根据ERT实时监测、采集、分析硫酸钡颗粒生成过程中电导率变化情况,得出电导率变化曲线,并采用扫描电子显微镜方法观察随着反应时间变化硫酸钡颗粒的形态变化情况。实验结果表明,使用ERT监测电导率变化可以得出不同浓度条件下电导率变化趋势及其浓度条件下的最适宜反应时间,并验证了采用电阻层析技术（ERT）对研究硫酸钡颗粒的形成具有较高的灵敏度,可用于研究硫酸钡颗粒的形成最适宜时间;用扫描电子显微镜观察络合法合成硫酸钡最开始形成一种梭型颗粒,随着钡离子的缓慢释放,硫酸钡颗粒不断生长,最终得到粒度均匀、分散性良好的球形硫酸钡颗粒。     

Solution properties of a hyamine based on N,N‐dimethyl diallyl ammonium chloride–acrylamide copolymer

A hyamine based on N,N‐dimethyl diallyl ammonium chloride–acrylamide copolymer was successfully synthesized in this study. Solution properties of this hyamine including electrical conductivity and viscosity behavior were studied in detail, and effects of temperature and counter ion concentration on electrical conductivity of the solution were also discussed. It was found that a solution of hyamine in water showed a typical viscosity behavior of polyelectrolytes, which followed the Fuoss equation. With the increase of ion radius (cationic ion or anionic ion), or with the increase of salt concentration, the shrinkage degree of the polymer chain increased, with a concomitant decrease in reduced viscosity and intrinsic viscosity and an increase of Huggins constant. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 90: 765–771, 2003     

Electrically conductive composites prepared from 3-methyl thiophene by the FeCl3 oxidation method

Surface conductive polyurethane films from poly(propylene glycol), toluene 2,4-diisocyanate, 3-methyl thiophene and butyltin dilaurate can be successfully prepared by the diffusion-oxidative polymerization method. Various effects of the doping conditions, such as the reaction time, the FeCl₃ concentration, the weight ratio of the 3-methyl thiophene to PU and the temperature on the electrical conductivity and thickness of the conductive layer of the 3-methyl thiophene/PU composite were investigated. Decomposition temperature rises gradually from pure undoped PU to doped composite that indicates blending took place in FeCl₃/ethyl acetate solution. As oxidative reaction time increases, the electrical conductivity of the 3-methyl thiophene doped PU film increases together with the thickness of the coating layer. With increasing FeCl₃ concentration and weight ratio of the 3-methyl thiophene to PU, the thickness of the coating layer decreases, while the electrical conductivity increases. The increase of the thickness of the PU film leads to the rise of the electrical conductivity. The thickness of the coating layer decreases, while the electrical conductivity of the 3-MT doped PU film increases with increasing reaction temperature. As the reaction time and temperature increase, the polar components of the PU film increase resulting into the increase of moisture regain value.