Polyoligomeric silsesquioxane (POSS)–hydrogenated polybutadiene polyurethane coatings for corrosion inhibition of AA2024

A series of coatings were developed that help prevent corrosion of aluminum alloy 2024 (AA2024). The coatings were based on an aliphatic polyurethane–polyoligomeric silsesquioxane (PU–POSS) resin. The materials were selected to exhibit a high level of hydrophobicity, which is expected to increase the moisture barrier properties, and thereby improve corrosion prevention. In addition, corrosion inhibitors (free molecules or encapsulated) were introduced into the coatings to improve corrosion resistance. The performance of the coatings was quantified using electrochemical impedance spectroscopy (EIS) and salt fog testing. Results from various formulations show that the hardness of the coating can be controlled by adjusting the ratio of POSS to hydrogenated hydroxyl terminated polybutadiene in the formulation. The coatings also had remarkable barrier properties, fast curing, and very high adhesion to the treated AA2024 substrate, all of which are expected to improve the anti-corrosion properties of the coatings. The best corrosion protection of AA2024 was observed in a transparent 10 μm thick PU–POSS bilayer coating that contained a mixture of sodium-2-mercaptobenzothiazole (i.e., NACAP) and benzotriazole-laden hydrotalcite. It was found that only certain corrosion inhibitors (free molecules or encapsulated) improve the anti-corrosion properties of the coating, whereas other corrosion inhibitors may actually degrade the coating performance.     

铜电解PLC控制系统的设计与应用

介绍PLC控制系统在铜电解生产中的应用,主要阐述控制系统的结构和特点,以及系统组态软件的上、下位机的设计方法及基本原则。系统运行结果表明,控制系统能满足实际生产工艺要求,性能稳定,可靠性高。     

铝电解惰性阳极材料选择的研究进展

论述了传统碳素阳极的缺点及使用惰性阳极的意义,提出了惰性阳极材料应符合的要求,重点阐述了国内外对金属氧化物陶瓷阳极、金属陶瓷阳极、金属阳极的研究成果并总结了以上三类惰性阳极有待进一步解决的主要问题。     

浅对烟气分析仪在污染源监测中准确性的探讨

文章针对烟气分析仪在污染源监测中容易引起监测数据偏差的因素做系统分析,结合烟气成分、电化学气体传感器工作原理及适用性、气体交叉干扰特性、做好仪器的检查校准和仪器的正确操作与预处理等方面,提出使用过程中的质量控制要点,以保证烟气分析的准确性。     

高导热系数聚丙烯复合材料的制备及研究

将氧化镁、氧化铝和石墨分别与聚丙烯熔融共混制备导热复合材料,考察了填料种类、基体黏度和增容改性对复合材料导热系数(λ)的影响。结果表明:增加填料含量能逐渐提高λ,且填料的λ直接决定了复合材料的λ;基体黏度越高,复合材料导热性能提高越显著;对氧化镁和氧化铝进行表面改性同时加入增容剂,可以明显减少填料的团聚,形成更多的有效网链,能有效提高复合材料的导热性能。探究了将氧化镁和氧化铝分别与石墨复配来制备高λ的复合材料,发现少量石墨与无机填料复配可以大幅提高复合材料的λ,当聚丙烯/增容剂/氧化镁/石墨质量比为30/10/50/10时,λ达到1.267 W/(m K),比不添加石墨时提高了50%;而对于氧化铝和石墨的复配体系,λ为0.622 W/(m K),相比于未添加石墨时增加了60%。     

Aluminum-doped ceria-zirconia solid solutions with enhanced thermal stability and high oxygen storage capacity

A facile solvothermal method to synthesize aluminum-doped ceria-zirconia (Ce_0.5Zr_0.5-xAl_xO_2-x/2, x = 0.1 to 0.4) solid solutions was carried out using Ce(NH₄)₂(NO₃)₆, Zr(NO₃)₃·2H₂O Al(NO₃)₃·9H₂O, and NH₄OH as the starting materials at 200°C for 24 h. The obtained solid solutions from the solvothermal reaction were calcined at 1,000°C for 20 h in air atmosphere to evaluate the thermal stability. The synthesized Ce_0.5Zr_0.3Al_0.2O_1.9 particle was characterized for the oxygen storage capacity (OSC) in automotive catalysis. For the characterization, X-ray diffraction, transmission electron microscopy, and the Brunauer-Emmet-Teller (BET) technique were employed. The OSC values of all samples were measured at 600°C using thermogravimetric-differential thermal analysis. Ce_0.5Zr_0.3Al_0.2O_1.9 solid solutions calcined at 1,000°C for 20 h with a BET surface area of 18 m² g⁻¹ exhibited a considerably high OSC of 427 μmol-O g⁻¹ and good OSC performance stability. The same synthesis route was employed for the preparation of the CeO₂ and Ce_0.5Zr_0.5O₂. The incorporation of aluminum ion in the lattice of ceria-based catalyst greatly enhanced the thermal stability and OSC.     

Synthesis of 3D nanostructured metal alloy of immiscible materials induced by megahertz-repetition femtosecond laser pulses

In this work, we have proposed a concept for the generation of three-dimensional (3D) nanostructured metal alloys of immiscible materials induced by megahertz-frequency ultrafast laser pulses. A mixture of two microparticle materials (aluminum and nickel oxide) and nickel oxide microparticles coated onto an aluminum foil have been used in this study. After laser irradiation, three different types of nanostructure composites have been observed: aluminum embedded in nickel nuclei, agglomerated chain of aluminum and nickel nanoparticles, and finally, aluminum nanoparticles grown on nickel microparticles. In comparison with current nanofabrication methods which are used only for one-dimensional nanofabrication, this technique enables us to fabricate 3D nanostructured metal alloys of two or more nanoparticle materials with varied composite concentrations under various predetermined conditions. This technique can lead to promising solutions for the fabrication of 3D nanostructured metal alloys in applications such as fuel-cell energy generation and development of custom-designed, functionally graded biomaterials and biocomposites.     

Al-doping induced superior lithium ion storage capability of LiNiO2 spheres

To optimize the performance of LiNiO₂ with minimal modification of the pristine structure, a facile solid-state approach, based on the interdiffusion of elements at the solid/solid interface, is developed to achieve uniformly Al-doped LiNiO₂ using alumina coated Ni(OH)₂ spheres as the precursor. The resulting LiNi_0.95Al_0.05O₂ material exhibits excellent discharge capacity (209.9 mAh g⁻¹ at 0.1 C) and cycling stability with a capacity retention of 85.10% after 200 cycles at 0.5 C. This is ascribed to the improved reversibility of the phase transitions by Al-doping as revealed by in-situ XRD characterization. The Al-doping also endows the material with superior rate capability due to the enlarged interlayer spacing in the structure and alleviation of the side reactions at the electrode/electrolyte interface, favorable for lithium ion diffusion. An optimal amount of doped Al is necessary for ensuring the structure stability and interface ionic conductivity of the LiNiO₂ spheres. Thus, the present strategy may provide an opportunity to optimize the performance of LiNiO₂, with uniform doping of a small amount of Al, producing a promising cathode material for advanced lithium ion batteries.     

硫酸根对离子膜电解工艺影响及处理

离子膜电解工艺中,硫酸根的影响有:硫酸根易与钙离子结合,降低氯气纯度,降低电解槽电流效率。提出去除硫酸根的方法有:钡法,钙法,碳酸钡法,树脂吸附法,膜法,以及膜法+冷冻结晶法。     

Growth behavior of aluminum borate whiskers on zirconia toughened alumina (ZTA) particle surface

In this work, B₄C-covered zirconia-toughened alumina (ZTA) particles are prepared and oxidised at 1050 °C for different times (0, 2, 4, and 8 h) in air. The X-ray diffraction and electron probe micro-analysis results show that the covering layer is mainly composed of oxide B₂O₃ intermetallics, residual B₄C particles, and Al₁₈B₄O₃₃ whiskers. The scanning electron microscopy results show that the growth of Al₁₈B₄O₃₃ whiskers on the ZTA particles enhances with increasing heat preservation time; the optimum holding time is determined to be 8 h Al₂O₃ in the ZTA particles diffuse into the covering layer and combine with B₂O₃ to form Al₁₈B₄O₃₃ whiskers; the Al₁₈B₄O₃₃ whiskers grow via the liquid-solid mechanism.