Chemical Relaxation of Surface Reactions

The study of the rate of self-adjustment of a homogeneous, chemically reacting system that has been perturbed from its thermostatic equilibrium has received much attention recently, and has been very fruitful in unraveling the details of the molecular encounters underlying chemical changes. Of singular interest has been the study     

Theory of Ion Exchange and Development of Charge in Kaolinite-Water Systems

Crystal-chemical concepts applied to cation adsorption on kaolinite crystals in a water medium permit the calculation of bond energies. These values place the cations in the proper sequence of replacing power. Comparison of bond energies with thermal energy makes possible the calculation of charge on the particle and explains much of the observed behavior of kaolin-water systems.     

Ion Beam Induced Charge characterization of epitaxial single crystal CVD diamond

IBIC (Ion Beam Induced Charge) technique has been used in order to characterize single crystal epitaxial CVD diamond film with respect to homogeneity and stability of the response (in terms of charge collection efficiency, cce) as a function both of counting rate and of the number of counts per unit surface area. The maximum shift of cce peak, under a 1.2 MeV proton microbeam, is 1.5% for counting rates from 43 to 4330 Hz, while the homogeneity, evaluated as the standard deviation with respect to the average value of cce over strip-like regions 60–100 μm wide and 800–1200 μm long, is 0.5%. Counting rates per unit surface area were between 30 and about 15,000 Hz/mm². A total number of counts per unit area up to 9 10⁶ counts/mm² was reached without noticing any polarization effect due to trapped charge. Moreover, the functionality of a new kind of bulk electrode, realized by a boron doped buffer layer laterally contacted with Ag paste, has been checked by measuring cce at different proton ranges.     

离子交换树脂对铜离子吸附交换行为的研究

采用335弱碱性阴离子交换树脂交换吸附酞菁绿废水中高含量的铜离子。研究结果表明,335OH型树脂的交换吸附和脱附性能均优于701Cl,701OH及335Cl树脂,其干树脂的静态吸附交换容量大于120mg/g,工作交换吸附容量43.68mg/g,单柱20BV时铜的去除率可达93%以上,双柱串联处理60BV的去除率在99.91%以上,可确保出水中铜含量达到国家二级排放标准。选用8%HCl溶液为脱附剂,脱附率大于95%,从脱附液中可回收氧化铜,从而实现资源化的目的。树脂经再生后可重复使用,性能稳定,具有良好的应用前景。     

离子交换对磷酸盐玻璃表面裂纹扩展的影响

采用LiNO3和NaNO3混合熔盐在250℃对N31型磷酸盐玻璃表面进行离子交换处理,研究了小离子交换大离子对玻璃表面和亚表面裂纹的扩张作用.利用偏光显微镜、扫描电子显微镜、能谱仪对离子交换前后玻璃表面形貌和成分进行了测试,根据有限源扩散动力学和离子交换表面应力分布理论,分析了离子交换时间和H2O对裂纹扩张的影响.结果...     

Novel Bifunctional Resins in Metal Ion Separations: Ion Exchange/Coordination Resins and Ion Exchange/Precipitation Resins

Abstract

Dual mechanism bifunctional polymers (DMBP's) as metal ion extractants are described within the context of two new examples. The carboxylic acid/pseudocrown resin is a new example of the DMBP class of resins described as ion exchange/ coordination resins. The polyethylene glycol ligand within the resin functions as a coordinating site for metal ions which are brought into the resin via ion exchange with the acid ligand. Initial studies with alkali metal ions are presented. The third general class of DMBP's is also presented. In this case, precipitation is the reaction occurring along with ion exchange thus yielding the ion exchange/precipitation resins. Barium recovery from aqueous solution via barium sulfate precipitation is described.     

Longxing Chemical Profit Decreased Due to Economic Situation

Recently, Zhongding Holding successfully acquired Germany KACO company engaged in producing high-end seals, with the total investment of 180 million BRL （about USD 80 million）.     

离子交换树脂复苏技术在化肥厂脱盐系统的应用

大庆石化分公司化肥厂脱盐水装置共有3列浮动床,每列均有阳浮床、阴浮床和混床,所用原水为石灰软化水.2002年经过技术改造将合成工艺冷凝液和尿素水解水投入脱盐系统部分代替石灰软化水,提高了浮床的周期制水量,2003年4月又将尿素蒸汽冷凝液投入脱盐系统,进一步提高了浮床的周期制水量.     

The Effect of Surface Composition and Structure on Elementary Chemical Reactions on Metallic Substrates

Studies of chemical reactions on well-defined surfaces have considerable potential for providing fundamental knowledge of surface reactivity and guidelines for the understanding of catalytic materials. with the use of low energy election deffraction (LEED)[1,2] surface structures can be diferentiated and the effect of these structures on surface reactivity determined. In addition, the relative case of obtaining surfaces of known composition utilizing Auger electron spectroscopy (AES)[3-5] makes it possible to study metal surfaces with less than 1% impurity and, moreover, to prepare surfaces with known coverages of adatoms such as carbon, oxygen, and sulfur in order to study the effects of these spacies on the activity and selectivity of the surface for given reactants. In some cases, as illustrated of the surface adatoms.     

Strengthening of Alumina by Reactions with Silicon Film on the Surface and Effects of Ion Irradiation

Deposition of Si film on sintered alumina, followed by annealing at 1673 K in air, increased the flexural strength by ∼28%. Mullite formation on the surface was confirmed by X–ray diffraction analysis. Ion irradiation of the Si/alumina interface, followed by annealing, produced anorthite but not mullite, and the flexural strength also increased by ∼35%. Thermal expansion mismatch between surface compounds and the alumina body may be responsible for the strengthening.     

Ion Exchange Resin Applied to Obtain Clarified Cashew Juice

The condensed tannins present in cashew apple juice provide high astringency, which is undesirable for this product. This study aimed to remove the cashew apple juice tannins by ion exchange for obtaining the clarified cashew apple juice (cajuína). Two strong base resins were used (macroporous and gel type). The effect of the process variables: temperature, resin:juice ratio, and stirring speed were determined. The macroporous resin presented better results with condensed tannins removal up to 80% in optimal conditions (30°C, ratio 1:6, 122 rpm). The cajuína obtained was clear and translucent, with low astringency, acidity, and °Brix according to Brazilian legislation.     

Adhesive Strength Study and Surface Analysis Using Gas-Phase Chemical Reactions of Atmospheric Pressure Plasma-treated Polypropylene

Adhesive strength of Atmospheric Pressure Glow (APG) plasma-treated polypropylene was studied for various gas mixtures by a scratching test. An explanation of the high adhesive strength obtained after He/N₂ APG plasma treatment was given. Formation of carbonyl, alcohol, carboxylic and primary amines was investigated by gas-phase chemical reaction. Their evolution during the ageing of the treated samples was followed. Most changes take place during the first few hours of contact with the atmospheric medium. Contact angle measurements on APG plasma-treated PP were done. These results were compared with PP treated by Silent Electric Discharge (SED). The ageing of the wettability properties of the surface after APG plasmas is better than after SED discharge.     

Enrichment Factor,Height of Separation Unit,and Separation Efficiency by Ion Exchange with Chemical Reaction

Abstract

The enrichment factor (?_u) in the separation unit of ion-exchange and chemical reactions is a function of the enrichment factor of the chemical reaction (?_r,s) and the “equilibrium coefficients” (ζ) which are determined only by the distribution of the ions in both the solution and ion-exchange phases. The factor can be simply expressed as ?_u = ζ?_r,s. The height of the separation unit is the sum of heights due to ion exchange, chemical reaction, and flow pattern. The height is also due to the “kinetics coefficient” (ζ), which is a function of the distribution as well as the “equilibrium coefficient.” The separation efficiency is proportional to ζ/√υ, both of which depend on the concentration of ions in the unit. Several schemes for the separation units are also discussed.     

Experimental Study on Charge Decay of Electret Filter Due to Organic Solvent Exposure

The electret filter is a potential component to remove airborne particles due to its high collection efficiency and low pressure drop. However, its filtration performance is gradually decreased by exposure to organic solvents, which limits the application of electret filters. The effect of ethanol exposure on the filtration performance of polypropylene electret filters was investigated experimentally to clarify the charge decay phenomenon in this study. Experimental results revealed that filter performance is strongly dependent upon the challenged mass and existing state of an ethanol solvent. The filter performance was drastically degraded by exposure to ethanol droplets generated from a solution with ethanol concentrations above 30%; however, it was maintained during exposure to ethanol vapors. This tendency was also seen in the surface potentials of the exposed filter media. In addition, we found that the critical challenging amount of ethanol droplets was in the vicinity of 0.045 g/cm² to neutralize a tested electret filter in this study.

Copyright 2015 American Association for Aerosol Research     

用二步法离子交换对手机玻璃面板进行强化和韧化

一步法离子交换对手机玻璃盖板增強,已在生产中应用,玻璃表面应力值虽然很高,但玻璃的抗冲击強度不高。两步法可以优化玻璃表面应力的分布,减少内部张应力,从而提高玻璃的抗冲击强度,而且还可以有效地利用硝酸钾熔盐。本文综述二步离子交换法所用熔融盐组成、温度制度以及玻璃表面应力分布,讨论了两步离子交换法增靱的机理。     

离子交换技术与镀镍废水处理

1前言 我国电镀废水处理经过50年的发展,镀镍废水的处理主要有化学法、离子交换法、蒸发浓缩回收、电解法和膜分离技术等.其中,离子交换技术因出水水质好,可回收有用物质,适用于处理浓度低而废水量大的镀镍废水等优点,曾得到广泛的应用.离子交换法应用于镀镍废水处理的主要功能有:(1)去除重金属镍离子,以应对日趋严格的排放标准;(2)回收废水中有价值的金属镍;(3)提高水的循环利用率,节约日益匮乏的水资源;(4)减少环境污染.