固体可逆接触式微型玻璃电极的成分与性能

体可逆接触式玻璃电极以固体合金代替溶液，可解决常用的液体接触式玻璃电极安全性问题，而且易于微型化。本文研究了固体可逆接触式玻璃电极敏感玻璃所用Li2O—La2O3—Ta2O5—SiO2系统成分及物理化学性质，用La2O3代SiO2对玻璃析晶、软化点、膨胀系数、耐水性和电导率的影响。用所研究成分制成的微型玻璃电极在pH1～7间转换系数96％以上，与pH值对应的响应电势E呈直线关系，有较好的氢离子选择功能，滞后误差小，测定数据的重复性也较好，符合医用微型玻璃电极的性能要求。     

医用微型玻璃电极的结构与特性

医用微型玻璃电极采用固体可逆接触式结构 ,直径 2mm ,长约 7～ 8mm。电极用于测定人体胃液pH值与电位差 ,可诊断胃病与早期发现胃癌。研究了微型玻璃电极敏感玻璃膜的成分与性质 ,在Li2 OLa2 O3SiO2 系统中加入摩尔分数为 2 %的Ta2 O5可提高敏感玻璃的耐水性与电导率。电极在 pH值为 1～ 9范围内具有良好的Nernst响应性 ,而且重现性和稳定性均比较好。电极的酸误差较小 ,电势随时间的漂移率约为 1.5mV/h。对 2 5只大白鼠胃液的 pH值和电位差进行测定 ,测得大白鼠胃液的pH值范围为 2～ 5。与PB 2 0型SartoriusAG酸度计所测的pH值相比较 ,得知此种电极的平均偏差较小 ,约为± 0 .2。人体正常胃液酸度范围的pH值为 2～ 3 ,由此判断电极用于人体胃液的测定是可能的。     

电极间玻璃电阻的计算

通常设计一个电熔炉所需的功率,都是参考现有窑炉的有关数据.在确定了窑炉所需的功率之后,电极的类型及相关的变压器二次特性(即电流、电压范围、电气设备的容量)也就可以确定了.然而这些量与玻璃液的电阻关系甚大,所以电极间玻璃液的电阻必须预先的估计出来.影响玻璃液电阻的因素有:玻璃的成分、玻璃液的温度,电极的型号、电极的插入方式、电极尺寸的大小、电极间距、电极与侧墙之间的距离等.     

电镀废水处理pH测控的相关问题

为了保证电镀废水处理中pH测控的准确性,介绍了玻璃电极的结构及pH测量的原理,指出了玻璃电极的缺陷(如高输入阻抗、电极的污染与腐蚀)对pH测控的影响,给出了电极清洗及pH计校正的一般方法,提出了自动报警或投药装置在使用中应注意的问题。     

冷顶式全电熔玻璃池窑

论述了玻璃电熔原理,从电熔窑结构、电极、冷顶工艺、安装高试和生产维修等方面阐述了电熔窑的优越性,并展望了电熔窑发展的广阔前景。     

用玻璃pH电极作参比电极在酸性介质中测定氟离子

基于弱酸根离子在不同酸度溶液中的化学平衡和离子选择电极的响应特征,本文试验了以氟电极为指示电极,玻璃pH电极作参比在pH<2的酸性介质中测氟的新方法。本法试用于一些特殊的工业中氟离子的直接测定,而不需进行pH调节和少量铝离子的掩蔽。     

高铁黑色玻璃的全电熔熔制

介绍了高铁黑色玻璃的全电熔熔制工艺,讨论了玻璃组成对着色和电熔的影响以及电极的选择和电熔窑的设计等有关内容.铁电极冷顶全电熔池窑熔制黑色玻璃的应用效果表明,熔化热效率72%,单位电耗0.714kWh/kg_(玻璃),电极一次投资1.509～2.000元/t_(玻璃)·d,电极消耗仅为钼电极的1/10.     

玻璃电熔炉钼电极铸造式水套结构的研制

玻璃电熔技术广泛应用于玻璃生产中。钼电极作为玻璃电熔炉中不可缺少的电极部件和消耗品,如何降低它在空气中的氧化速率,保证钼电极长期稳定工作,是设计建造玻璃电熔炉的重要工作之一。在生产中研制了两种钼电极水套,经过多年的生产实践验证,玻璃电熔炉钼电极铸造式水套结构设计合理,加工制造性能良好,使用寿命长,可广泛运用于电熔玻璃生产当中。     

顶插式铁电极全电熔制黑色玻璃的工艺研究

本文介绍了全电熔熔制黑色玻璃应用的顶插式铁电极情况，是目前熔制黑色玻璃或类似这种玻璃的最节省的办法。     

钼电极与玻璃电熔炉中各组份作用的热力学计算

通过计算钼电极与玻璃中各组份的反应自由能,不需要做实验就可以确定哪些玻璃成份与钼电极起反应,从而确定熔化哪些玻璃成分的窑不能使用钼电极。     

Ion-selective electrodes with superhydrophobic polymer/carbon nanocomposites as solid contact

Possibility of using superhydrophobic polymer/carbon nanocomposites as a new type of solid-contact material for solid-state ion-selective electrodes has been presented for example potassium-sensitive electrodes. The solid contact layers were prepared with the highly porous graphene/carbon black – fluorinated acrylic copolymer. Potassium-selective electrodes were exhibited a good Nernstian response with a slope of 59.10 mV/dec in the range from 10^−6.5 to 10⁻¹ M KCl. The stability of the electrical potential of the new solid-contact electrodes was tested by performing current-reversal chronopotentiometry, and the electrodes capacitance is 1471 μF. Due to the large capacitance and super hydrophobic character of the solid contact the developed electrodes exhibit excellent a long-term potential stability.     

Electrochemical synthesis of melanin free-standing films

Free-standing melanin films were successfully synthesised electrochemically from dopa. The optimum synthetic conditions such as pH, concentration and current were determined, and it was found that free-standing films could only be formed when ITO glass electrodes were used. The films were analysed by solid state NMR and XPS which showed the presence of indolic moieties characteristic of melanin-type macromolecules. The film showed higher conductivity than chemically synthesised melanin previously reported in literature and also exhibited photoconductivity.     

On bitumen liberation from oil sands

Laboratory experiments were performed to investigate the effect of pH on (a) bitumen film thinning and film rupture process (b) bitumen/water contact line displacement and (c) the static contact angle of bitumen on a glass surface in the presence of an aqueous medium. A coated bitumen film on a glass surface was found to thin down and rupture spontaneously when a few drops of water having a pH of 11 was placed on it. In another experiment, a bitumen coated glass plate was submerged in water. The contact line of an initially circular bitumen film on the glass surface displaced in the inward direction to take the shape of a droplet. Measurement of the dynamic contact angle of bitumen with time showed that the bitumen/water contact line displacement was faster at a pH of 3 than at a pH of 11. However, the static contact angle of bitumen on the glass surface was found to be large at the high pH of 11, a condition conducive to easy detachment of bitumen droplet from the glass surface. The above observations suggest that a pH cycle might be desirable in bitumen liberation from oil sands.     

一种新型氢化反应搅拌器的改进

在化工生产过程中,氢化反应是一种较为复杂的单元过程,促进氢化反应顺利进行的因素有温度、压力、介质、酸碱度、催化剂以及物料的接触状态。从生产实际出发,剖析了氢化反应进程中固、液、气3种状态的反应物料,因搅拌能力不足致使反应速度缓慢的原因,并根据问题所在,有针对性地改变搅拌器型式,采用新型设计的组合型多层搅拌器可以使固、液、气三相能充分混合,增加了参与反应物料的接触面积,提高了气、液反应能力和催化剂的催化作用,达到加快生产反应速度的目的,缩短了反应时间,提高了产品收率。     

Slow drift modeling and compensation in the glass electrode dynamics for the fast measurement of pH

Glass electrodes for measuring pH in solutions show relatively fast responses with slow drifts. To design compensators to remove the drifts that hinder fast measurements of pH, a dynamic model that consists of ordinary and partial differential equations is proposed. It can explain such two-time scale responses of glass electrodes. The fitting accuracies of the proposed model are experimentally evaluated in frequency-domain and time-domain. The frequency responses obtained from the square wave responses show the fitting abilities of the proposed model, and the step responses also support this. The step responses filtered based on the proposed model show that pH measurements can be made considerably faster. The proposed model can be used to improve the dynamics of glass pH electrodes by compensating dynamic elements causing slow drifts.     

Removal of copper and cadmium from hydrometallurgical leach solutions by fluidised bed electrolysis

A fluidised bed cell which consists of a bed of inert glass beads, in which are immersed expanded mesh electrodes, is used to provide high ion transfer conditions making it possible to recover metals efficiently from dilute solutions. The use of the cell in the removal of Cu and Cd from dilute solutions is described, and the effects of cathode density, pH, time, type of electrode, distance between the electrodes and presence of other ions in solutions studied. These investigations are then extended to examine the electrolysis of solutions obtained by leaching a copper—zinc calcine.     

Effect of Bismate Frits Under Fast Firing on Reactions Between Ag Electrodes and Si Wafer for Si Solar Cells

Leaded frits in Ag pastes have generally been used to fabricate Ag electrodes. The bismate glass system has been reported to be an appropriate frit for use in Ag pastes for eco‐friendly materials. The characteristics of bismate frits under fast firing were first studied to elucidate the phenomena occurring in the molten glass. To determine the reactions among Ag, frits, and an Si wafer coated with SiN_x, the interfacial structures between Ag electrodes and the Si wafer were investigated using scanning electron microscopy coupled with energy‐dispersive X‐ray spectroscopy (EDX), transmission electron microscopy coupled with EDX, and X‐ray photoelectron spectroscopy. The precipitates formed in the molten frits were found to be Bi nanoparticles. The interfacial structures between the Ag electrodes and the Si wafer consisted of Ag electrodes, glass layers, and recrystallites formed in the n⁺ emitter. The recrystallite elements existed as Ag–Si and Ag–Bi–Si, which are segregated, as well as Ag. These results suggest that the contact formation between the Ag electrodes and the Si wafer was caused by the characteristics of bismate frits in Ag pastes under fast firing.     

催化剂对聚乙烯醇缩甲醛改性PVAc乳液性能的影响

以聚乙烯醇缩甲醛（PVF）为保护胶体,采用半连续种子乳液聚合方法,合成了固含量为18％左右的聚醋酸乙烯酯（PVAc）乳液,研究了缩醛反应的催化剂种类（硫酸H2SO4、盐酸HCl）、pH值对乳液中游离甲醛含量、缩醛度、黏度及对胶接强度的影响。采用傅里叶变换红外光谱（FTIR）、接触角测量等对乳液的结构和性能进行了表征。研究结果表明,不同的催化体系对乳液性能的影响不同。随着pH4值的降低,乳液中游离甲醛含量降低,PVF的缩醛度升高,乳液黏度和胶接强度均呈先升高后降低的趋势。催化荆种类和pH值对乳液接触角无显著影响。用H,SO。作为缩醛反应的催化剂,反应的pH值为34时,合成乳液的综合性能最佳。     

Bezugselektroden für elektrochemische Messungen

Reference Electrodes for Electrochemical Measurements Recent advances in the development of reference electrodes for amperometric and voltammetric measurements are reviewed. The suitability of all-solid-state electrodes as reference electrodes for pH measurement for use with an glass electrode and for other potentiometric measurements is evaluated. The role of new technologies, as thick film and as thin film technology, are discussed. References for microelectrodes are represented.     

固态金属锂电池研究进展：外部压力和内部应力的影响

固态锂金属电池具有理论能量密度高、安全性高等优势,是极有前景的下一代储能系统。然而,固体电极与固体电解质之间有限的固–固接触严重阻碍了界面离子的传输。因此,增加外部压力是增加固–固接触及延长电池循环寿命的重要途径。同时,在充放电过程中,电极体积变化产生的内应力也将影响电池界面特性。通过介绍两种基本物理接触模型,结合硫化物、氧化物、聚合物电解质以及金属锂的物理性质,综述了外压和内部应力对电解质、电极及电池的影响。最后,对外压力与内应力在全固态金属锂电池中的作用进行了总结和展望。