Ag/AgCl氯离子传感器在混凝土中的应用

尝试将试验室制作的Ag/AgCl氯离子传感器用于混凝土中测试,验证该传感器应用于混凝土结构中的可行性。测试了传感器在混凝土试件中的长期稳定性,建立了传感器在混凝土中的线性响应方程,并通过加速氯离子渗透的方式对建立的线性方程进行了验证。试验结果表明,传感器在混凝土试件中可以长期稳定有效地工作,85d电位波动25mV,传感器在氯离子掺量相同的试件中电位响应一致性良好;通过建立的线性方程计算得到的电位响应值与实测电位响应值符合得很好,所建立的方程与试件水胶比水平无关,与氯离子的引入方式无关,是适用于混凝土结构的比较准确的线性方程。通过该方程的建立即可实现使用该传感器监测混凝土结构中的氯离子分布,达到钢筋锈蚀提前预警的目的。     

氯离子含量快速测定仪计量方法研究

构建氯离子含量快速测定仪的计量检测方法,完善氯离子含量快速测定仪量值溯源体系,从氯离子含量快速测定仪的整体性能进行综合评估,主要从仪器的主机性能、整机检测结果的准确性、重复性等几个方面规范检测技术方法,统一技术要求,规范评价标准。     

干湿循环作用对混凝土抗氯离子渗透侵蚀性能的影响

为了加速模拟海洋潮差区环境对混凝土耐久性能的影响,掺入矿粉和纳米改性矿物掺合料,研究了氯盐干湿循环作用对混凝土抗氯离子侵蚀性能及微观结构的影响,并将干湿循环试验与常规浸泡试验进行了对比。结果发现,干湿循环作用粗化了混凝土试件表层孔结构,增大了孔径>50 nm的孔隙含量,显著提高了自由及总氯离子浓度;掺入纳米改性矿物掺合料能降低混凝土内部孔隙率,减少有害孔含量,提高混凝土内部氯离子结合能力;干湿循环60天后混凝土表层Ca（OH）₂逐渐被消耗,生成了Friedel盐和CaCO₃。      

异喹啉及其衍生物在银电极上吸附行为的研究

借助于表面增强拉曼散射技术，研究了异喹啉及其衍生物在盐酸溶液中Ａｇ电极上的吸附行为。结果表明：异喹啉是通过Ｎ原子的作用垂直地吸附在Ａｇ电极表面上；５－羟基异喹、１，５－二羟基异喹啉和甲基－３异喹啉羧酸脂是通过环上的π电子与金属作用，平躺地吸附在金属表面上，其中５－羟基异喹啉的π反键轨道能接受金属表面电子密度的反馈，形成“反馈π键”，吸附作用较强；１－羟基异喹啉和１－羟基异喹啉分别通过Ｏ原子和ＣＯＯ     

树脂吸附稀醋酸中氯离子的应用研究

本文通过对树脂吸附稀醋酸中的氯离子情况的介绍,结合其检测的一些实验数据,提出了树脂对稀醋酸中氯离子吸附的应用可行性分析,以供相关的生产人员参考。     

海砂混凝土中氯离子固化的影响因素研究

通过海砂混凝土中游离氯离子含量的测定,研究了海砂混凝土氯离子吸附和结合特征.利用X射线衍射、扫描电镜和热分析等测试方法对海砂混凝土的微结构和Friedel盐进行了表征.结果表明:海砂混凝土游离氯离子浓度与溶液的萃取温度密切相关,温度越高,游离氯离子浓度越大,萃取温度为65℃时的游离氯离子浓度约为15℃时游离氯离子浓度的2倍;同时粉煤灰砂浆中结合的物理固化离子在较低温度下溶出率低.TG/DTA曲线上没有出现海砂混凝土的Friedel盐吸热峰,而XRD与SEM图中显示海砂混凝土中存在Friedel盐,可能是因为Friedel盐含量较少,导致生成的Friedel盐不稳定.     

氯离子含量快速测定仪校准方法的验证

文章主要通过实验验证所设计的氯离子含量快速测定仪校准方法的科学有效性和操作可行性,提出的计量特性和技术指标合理满足量值溯源要求,为保证该类仪器测量结果准确可靠提供了技术依据和支持。     

混凝土中氯离子含量的三种检测方法

本文详细的介绍了混凝土中常用的三种Cl-含量检测方法:铬酸钾法、电位滴定法、Cl-选择性电极法。其中铬酸钾法存在滴定终点时颜色难以辨认、精确度不高,人为误差较大;电位滴定法与Cl-选择性电极测氯离子测定法同属于电化学方法,但Cl-选择性电极不需要贵重试剂AgNO3,省去了AgNO3标准溶液的配制和滴定,所得数据标准偏差小,能够简单、经济、快速、准确地测定混凝土中氯离子的含量,值得推广。     

发射光谱法测定化探样品中银、锌的含量

发射光谱法测定化探样品中银、锌的含量,在WPG-100型一米平面光栅摄谱仪上摄谱,用GBZ-Ⅲ型光谱相板测光仪测量黑度并打印出测定的数据。本方法具有扫描速度快、识谱精确度高、精密度好等优点,测定结果令人满意。     

高长径比银纳米线合成过程中聚乙烯吡咯烷酮的影响机制研究

利用乙二醇还原法合成银纳米线。研究了表面活性剂聚乙烯吡咯烷酮的浓度、添加时间、滴加速度对产物形貌及银纳米线长径比的影响。结果表明,聚乙烯吡咯烷酮的添加细节影响了其对银纳米晶的包覆程度,从而影响了银纳米线的生成。优化实验参数为加入硝酸银14min后添加聚乙烯吡咯烷酮(浓度0.15mol/L,滴加速率15μL/s)。在此参数下可得到大量长径比200以上的银纳米线,以此银纳米线制备的电极,透光率达到70%以上,方块电阻为50.7Ω/cm2。     

混凝土腐蚀监测用参比电极制作及电化学性能研究

参比电极对监测混凝土中钢筋的电位至关重要。使用凝胶作为电极内部电解质、水泥浆作为渗透层,制成Ag/AgCl凝胶参比电极。在混凝土模拟液中测试了电极电位的稳定性、电极的温度系数以及氯离子含量对电位的影响,通过动电位和恒电流极化测试了电极的抗极化性能,并在混凝土中进一步研究了电极电位的时变特性。结果表明,电极电位有良好的稳定性和可靠性,电极温度系数较小,氯离子含量对电极电位的影响可以忽略,电极抗极化性能优良。研制的电极可用于实时监测混凝土内部钢筋的腐蚀电位,为钢筋混凝土构件寿命预测提供参考。     

Diffusion-controlled size-selective chloride ion sensing in the presence of bromide ion using a thin, nanoporous, plasma-polymerized coating on an Ag/AgCl electrode

We have developed a diffusion-controlled size-selective method for sensing chloride ion in the presence of bromide ion, based on a thin, nanoporous, plasma-polymerized coating of hexamethyldisiloxane on an Ag/AgCl electrode. Sub-nanometer-sized pores responsible for a highly cross-linked polymer network in the plasma-polymerized coating allowed diffusion-controlled permeation of chloride ion while blocking the larger bromide ion. An electrode coating of thickness greater than 70 nm enabled chloride detection in the concentration range 1-10 mM in the presence of 0.63 mM bromide ion. Advantages of this approach are: (1) simple design compared with ionophore-based strategies and (2) compatibility with microfabrication and mass production processes.     

高温高压环境腐蚀电化学研究用参比电极的制备及性能

对国外引进的高温高压参比电极不稳定性的原因进行了分析,并相应地作了改进:优化氯化工艺;改善密封结构;采用饱和KCl电解液,从而制得了性能良好的Ag/AgCl高温高压参比电极,建立了完善的高温高压电化学测试体系,解决了长期困扰模拟油气井高温高压环境中腐蚀电化学研究的难题.对比了原位法和离位法高温高压电化学测试的结果,证实将离位法测试结果用于分析高温高压油气井环境中油管钢的电化学腐蚀行为和机理是不合适的.     

碱激发材料氯离子传输性能测试方法及影响因素研究进展

水泥基材料中氯离子的传输是一个非常复杂的过程。在介绍水泥基材料氯离子传输机理及常用试验方法的基础上,综述了碱激发材料氯离子传输性能测试方法及影响因素。碱激发材料氯离子传输性能受激发剂种类的影响,改变矿渣掺量、碱掺量和水玻璃模数能不同程度地改变体系的氯离子传输性能。快速氯离子渗透试验结果受孔溶液化学组成影响,碱激发材料孔溶液碱性高、化学组成更复杂,孔溶液影响更显著,所以该方法不适用于评价碱激发材料氯离子传输性能。自然扩散试验因时间长而不常用。非稳态电迁移试验是目前快速测试水泥基材料中氯离子传输性能最好的方法,但由于碱激发材料与普通水泥基材料的碱度不同,其变色边界氯离子浓度也会不同,将该方法用于评价碱激发材料时,还需进一步研究测试样品的准备和硝酸银变色边界氯离子浓度。     

Electrolytes and Electrolyte/Electrode Interfaces in Sodium‐Ion Batteries: From Scientific Research to Practical Application

Sodium‐ion batteries (SIBs) have drawn considerable interest as power‐storage devices owing to the wide abundance of their constituents and low cost. To realize a high performance–price ratio, the cathode and anode materials must be optimized. As essential components of SIBs, electrolytes should have wide electrochemical windows, high thermal stability, and exceptional ionic conductivity. Therefore, improved electrolytes, based on various materials and compositions, are developed to meet the practical demands of SIBs, including organic electrolytes, ionic liquids, aqueous, solid electrolytes, and hybrid electrolytes. Although mature organic electrolytes are currently used in production, aqueous and solid electrolytes show advantages for future applications, as discussed here in detail. Current efforts in modifying electrolytes to optimize their interfacial compatibility with electrodes, leading to longer battery lifetimes and greater safety, are described. The advanced characterization techniques used to investigate the properties of electrolytes and interfaces are introduced, and the reaction processes and degradation mechanisms of SIBs are revealed. Furthermore, the practical prospects of SIBs promoted by high‐quality electrolytes appropriately matched with electrodes are predicted and directions for developing next‐generation SIBs are suggested.     

MOF‐Derived Hollow Co9S8 Nanoparticles Embedded in Graphitic Carbon Nanocages with Superior Li‐Ion Storage

Novel electrode materials consisting of hollow cobalt sulfide nanoparticles embedded in graphitic carbon nanocages (HCSP?GCC) are facilely synthesized by a top‐down route applying room‐temperature synthesized Co‐based zeolitic imidazolate framework (ZIF‐67) as the template. Owing to the good mechanical flexibility and pronounced structure stability of carbon nanocages‐encapsulated Co₉S₈, the as‐obtained HCSP?GCC exhibit superior Li‐ion storage. Working in the voltage of 1.0?3.0 V, they display a very high energy density (707 Wh kg^?1), superior rate capability (reversible capabilities of 536, 489, 438, 393, 345, and 278 mA h g^?1 at 0.2, 0.5, 1, 2, 5, and 10C, respectively), and stable cycling performance (≈26% capacity loss after long 150 cycles at 1C with a capacity retention of 365 mA h g^?1). When the work voltage is extended into 0.01–3.0 V, a higher stable capacity of 1600 mA h g^?1 at a current density of 100 mA g^?1 is still achieved.     

建立粗氖氦中氖气含量的分析方法

通过采用热导色谱仪,对空分生产的粗氖氦中氖、氢和氦等组分的检测进行探讨,建立了一种准确定量粗氖氦中氖气含量的分析方法。     

LaNiO3 modified with Ag nanoparticles as an efficient bifunctional electrocatalyst for rechargeable zinc--air batteries

No-precious bifunctional catalysts with high electrochemical activities and stability were crucial to properties of rechargeable zinc–air batteries. Herein, LaNiO₃ modified with Ag nanoparticles (Ag/LaNiO₃) was prepared by the co-synthesis method and evaluated as the bifunctional oxygen catalyst for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Compared with LaNiO₃, Ag/LaNiO₃ demonstrated the enhanced catalytic activity towards ORR/OER as well as higher limited current density and lower onset potential. Moreover, the potential gap between ORR potential (at −3 mA·cm⁻²) and OER potential (at 5 mA·cm⁻²) was 1.16 V. The maximum power density of the primary zinc–air battery with Ag/LaNiO₃ catalyst achieved 60 mW·cm⁻². Furthermore, rechargeable zinc–air batteries operated reversible charge–discharge cycles for 150 cycles without noticeable performance deterioration, which showed its excellent bifunctional activity and cycling stability as oxygen electrocatalyst for rechargeable zinc–air batteries. These results indicated that Ag/LaNiO₃ prepared by the co-synthesis method was a promising bifunctional catalyst for rechargeable zinc–air batteries.