PITTING CORROSION OF SAF2205 DUPLEX STAINLESS STEEL IN ACETIC ACID CONTAINING BROMIDE AND CHLORIDE

Development of duplex stainless steels has been linked strongly with the increasing requirements of the industry for resistance of materials to highly aggressive environments. In the present work, the effects of bromide and chloride ion concentrations and temperature on the pitting corrosion of commercial grade SAF2205 duplex stainless steel were studied. Cyclic polarization and scanning electron microscopy (SEM) techniques were used to study the pitting corrosion behavior of this steel in 80%v/v acetic acid solution containing 0.01, 0.1, 0.2, and 0.5 M sodium bromide and sodium chloride, respectively. Pitting potential was found to decrease with the increase of the temperature and bromide ion concentration. In the presence of chloride ions, pitting corrosion was not observed at room temperature. Critical pitting temperature in chloride-containing solutions was estimated to be above 35°C. In the case of pitting, SEM observation revealed that pit initiation is in the austenite phase regions.     

The anodic dehydrodimerization of dimethyl malonate

As a part of a study of the anodic dehydrodimerization of diethyl malonate on platinum in emulsions and micelles some experiments were run to obtain an insight on the mechanism of the reaction. It was determined that although some catalytic dehydrodimerization was obtained with pure diethyl malonate at elevated temperatures the yield from this type of reaction at room temperature was negligible. In pure acetonitrile, confirmation was obtained for the previously postulated mechanism which involved reaction at the anode of electrogenerated halogen with diethyl malonate anions which had been generated at the cathode.In aqueous emulsion and micelle systems it was found that yields of the dimer were obtained in the presence of bromide ions and a quaternary ammonium salt but were not obtained using other supporting anions including chloride. The best yields were obtained in emulsions composed of tetrabutylammonium bromide and water. It was concluded that the dimerization proceeded by a reaction between electrochemically generated bromine molecules and the diethyl malonate anion. No large amounts of bromine were found adjacent to the electrode if potassium bromide was the supporting electrolyte but bromine stayed in the neighborhood of the electrode if tetrabutylammonium ions were present.     

A water-activated cuprous bromide battery

In this work a water-activated copper(I) bromide battery was developed and investigated. CuBr combined with sulphur as the reactive cathode material was compared with the CuCl-sulphur combination, the anode being in both cases a magnesium alloy. Battery characteristics were tested at room temperature and in an atmosphere simulation chamber because water-activated batteries are mostly used in meteorological radiosondes. Heat evolution was studied calorimetrically, and the potentials of the single electrodes were measured in half-cell experiments. The practical voltages remained significantly lower than the theoretical ones. The low actual voltages of the batteries were found to be caused by the potential loss at the magnesium anode. The heat evolution power of the CuBr battery was approximately 20% lower than the power of the CuCl battery as a result of bromide ions that catalyse the exothermic corrosion reaction of magnesium less than chloride ions. The CuBr battery is environmentally preferable to the CuCl battery because the reaction that produces harmful Cu²⁺ ions does not progress with CuBr. The problem when using CuBr is the slow activation, which can be accelerated by adding soluble salts to increase the conductivity of the electrolyte.     

氯化钯催化偶联反应合成对-三联苯

用苯基格氏试剂与硼酸三正丁酯在室温下反应制得苯基硼酸,以苯基硼酸与对二溴苯为原料,以氯化钯为催化剂,以四丁基碘化铵为相转移催化剂及在碳酸钾的参与下,在水／苯为介质的非均相体系中进行偶联反应,合成了对 三联苯,产率达７０％（以对二溴苯计）。物料摩尔配比为：对二溴苯∶苯基硼酸∶氯化钯∶四丁基碘化铵∶碳酸钾＝１∶２．２∶０．０１∶１∶５。     

Membrane Characteristics and Fouling Study in MEUF for the Removal of Chromate Anions from Aqueous Streams

Abstract

Micellar‐Enhanced Ultrafiltration (MEUF) of the chromate anions from aqueous solutions has been studied at room temperature (28±2°C) using cationic surfactants, cetyltrimethylammonium bromide (CTAB), and cetylpyridinium chloride (CPC), micelles of which adsorb the chromate ions by electrostatic interactions. The solution is processed by ultrafiltration, using a membrane with a pore size small enough to block the passage of the micelles and the adsorbed ions. The process is highly efficient in removing the chromate ions. In the absence of other electrolytes, chromate ion rejections up to 99% were observed at optimal conditions of pH, pressure, temperature, feed chromate, and surfactant concentrations. The presence of added NaCl reduces the chromate rejection, but it was still considerable (up to 82%), even in the presence of 100 mM NaCl. The rejection rate of chromate was found to be highly dependent on the pH of the feed solution. The influence of membrane characteristics on the chromate ion removal was also studied. Various resistances like fouling resistance, concentration polarization resistance, and membrane resistance were also estimated to quantify their effects on the removal efficiency and on the flux behavior.     

Nylon 66, Nylon 46, and Pet Phase-Transfer-Catalyzed Alkaline Depolymerization at Atmospheric Pressure

The depolymerization of PET, nylon 66, and nylon 46 at high temperatures in an autoclave is well known in the patent literature. We sought to invent processes for the depolymerization of PET, nylon 66, and nylon 46 in alkaline solutions at low temperatures and atmospheric pressure. A method was developed for the depolymerization of polyethylene terephthalate (PET) which involved the use of quarternary ammonium salt phase-transfer catalysts in saponification processes at atmospheric pressure and temperatures as low as room temperature. Phenyltrimethylammonium chloride, hexadecyltrimethylammonium bromide, trioctylmethylammonium chloride, and trioctylmethylammonium bromide were found to be effective catalysts for the depolymerization of PET in 5% aqueous sodium hydroxide solutions at temperatures as high as 80°C and atmospheric pressure to form terephthalic acid in yields as high as 93%. The catalyst could be recycled. The alkaline phase-transfer-catalysis approach was then successfully applied for the depolymerizations of nylon 66 and nylon 46. Benzyltrimethylammonium bromide was discovered to be an effective phase-transfer catalyst in 50 wt.% sodium hydroxide solution for the conversion of nylon 46 to oligomers. The collected nylon 46 oligomers were repolymerized using solid-state polymerization techniques to form high-molecular-weight nylon 46. Nylon 66 fibers were depolymerized in the presence of benzyltrimethylammonium bromide in 50% sodium hydroxide to form oligomers and a monomer. Adipic acid was isolated.     

N-取代吲哚-3-甲醇的合成

首先由吲哚、三氯氧磷和N,N-二甲基甲酰胺通过Vilsmeier-Haack反应合成吲哚-3-甲醛,产率为97%;进而选择二甲亚砜-氢氧化钠反应体系,室温下由碘甲烷、烯丙基溴、溴化苄和甲苯-4-磺酰氯分别对吲哚-3-甲醛进行N-取代,合成4种N-取代吲哚-3-甲醛——N-甲基吲哚-3-甲醛、N-烯丙基吲哚-3-甲醛、N-苄基吲哚-3-甲醛和N-对甲苯磺酰基吲哚-3-甲醛,产率分别为89%、95%、83%和81%;最后选择硼氢化钠为还原剂,室温下通过还原反应合成吲哚-3-甲醇以及4种N-取代吲哚-3-甲醇——N-甲基吲哚-3-甲醇、N-烯丙基吲哚-3-甲醇、N-苄基吲哚-3-甲醇和N-对甲苯磺酰基吲哚-3-甲醇,产率分别为80%、90%、81%、63%和53%。中间产物及终产物的结构经由1HNMR、IR和元素分析证实。     

Effect of sulfate and chloride ions on the electrochemical behavior of iron in aqueous phosphate solutions

The electrochemical behavior of iron in aqueous phosphate solutions (0.005–0.1M) of pH8 at room temperature was investigated with an emphasis on the effect of chloride and /or sulfate ions on the initiation of the localized attack. Electrochemical techniques were complemented by SEM microscopy, FTIR, X-ray fluorescence analysis and ICP measurements. It has been shown that phosphate ions are very effective inhibitors against localized attack, and in the presence of sulfate ions still show an effect very similar to that of phosphate ions in the active–passive dissolution peak region.     

Kinetics of the reduction of Mn at the dropping mercury electrode in aqueous-dioxan mixtures

Reduction of Mn²⁺ has been studied in aqueous dioxan mixtures at a dropping mercury electrode. The reduction has been found to be quasi-reversible and hence kinetic parameters (K_s and ) have been calculated by Gellings' method. The K_s values are found to be in the order of 10⁻³ cm/s. The effect of halide ions has also been studied in aqueous dioxan solvent mixtures using sodium chloride and sodium bromide as base electrolytes in place of sodium perchlorate. The effect of temperature has also been studied.     

LiCl溶液垂直管外降膜发生效果的实验

为了探究LiCl水溶液在低位太阳能吸收式制冷系统中的发生过程中的传热传质效果,在降膜发生实验装置基础上研究了LiCl水溶液在垂直管外降膜发生的传热传质过程。阐述了不同运行工况如不同的热水和溶液的流量、热源的温度、溶液的浓度和系统压力对LiCl水溶液发生过程传热传质效果的影响。同时也进行了相同工况下LiBr水溶液的对比实验。结果表明相同运行工况下LiCl水溶液降膜发生过程和LiBr水溶液的降膜发生过程有着相似的变化规律。虽然LiCl水溶液的垂直降膜发生速率略低于LiBr水溶液,但传质效果相差不大,LiCl溶液的低运行浓度有利于循环热力性能的提升。     

Combination of Surfactant Action with Peroxide Activation for Room-Temperature Cleaning of Textiles

Room-temperature cleaning of textiles is commonly practiced in many countries for energy saving as well as custom in daily life, but not very effective for removing colored contaminants. In this work, it was proposed to combine surfactant action (SA) with peroxide activation (PA) in a peroxide activator to enable cleaning of textiles at room temperature. N-[4-(alkyldimethylammoniomethyl)benzoyl]lactam chloride was designed and synthesized as a prototype of the proposed peroxide activator, in which the alkyl chain with a carbon atom number of n was responsible for surfactant action and the N-benzoyllactam with a carbon atom number of m in the lactam ring was responsible for peroxide activation. Such a peroxide activator was hereby referred to as SAPA_m-n. The room-temperature cleaning performance of SAPA_m-n was examined by cotton fabrics contaminated with morin and waste engine oil, respectively. It was found that SAPA_m-n was able to activate hydrogen peroxide released from sodium perborate so as to effectively bleach the morin-contaminated cotton fabric at room temperature. Though extending the alkyl chain length of SAPA_m-n resulted in no apparent effect on the room-temperature bleaching performance, it enhanced the surfactant action which contributed to removing oily contaminants from textiles. Color-safe performance of SAPA_m-n was evaluated by cleaning a dyed cotton fabric at room temperature. It was found that the peroxide bleach activated by SAPA_m-n resulted in no apparent color change of the dyed cotton fabric. The results of this study provide new insights on textile cleaning at room temperature for the purpose of energy saving.     

Performance of a new cationic bleach activator on a hydrogen peroxide bleaching system

The performance of a cationic bleach activator, N -[4-(triethylammoniomethyl)benzoyl]caprolactam chloride, was evaluated in a hot peroxide bleaching process. The effect of time, temperature and the concentrations of hydrogen peroxide and activator on the bleaching of cotton fabric was investigated using a central composite experimental design. Temperature was found to be the most significant parameter. By adding the cationic activator it was possible to achieve a level of whiteness comparable to a typical commercial bleaching system but under relatively mild conditions of time and temperature. As a consequence, chemical damage to the fabric could be reduced. The effect of the cationic bleach activator was compared to that of an anionic activator, nonanoyloxybenzene sulphonate. The cationic activator was superior to the anionic activator in bleaching the fabric under the optimised conditions used in the study. Received: 13 January 2004, Accepted: 10 March 2004     

N-马来酰化壳聚糖及其配合物的合成与表征

碱性条件下将壳聚糖脱晶,利用红外光谱（FT-IR）对其结构进行了确证,并以N,N-二甲基甲酰胺和无水乙醇为介质,将脱晶壳聚糖与马来酸酐在室温条件下摩尔比按1∶1进行酰化反应18 h,合成了取代度DS=63%的N-马来酰化壳聚糖。由FT-IR测试的结果表明了马来酸酐成功接到壳聚糖分子的氨基上。将制备的N-马来酰化壳聚糖在室温下分别与氯化锌、氯化铜反应6 h,制得N-马来酰化壳聚糖与二价锌离子和二价铜离子的配合物。采用FT-IR及电子顺磁共振光谱（EPR）对配合物的结构进行表征。结果表明,N-马来酰化壳聚糖在温和条件下能与Cu(Ⅱ)、Zn(Ⅱ)形成配位化合物,N-马来酰化壳聚糖中的氨基与羧基共同参与配位。     

Preparation and characterization of poly(dimethyldiallyl ammonium)chloride and antiglobulin tests for antibody detection

Poly(dimethyldiallyl ammonium)chloride [poly(DMDAAC)] was prepared in our laboratory and monomer‐to‐polymer structures were characterized by infrared (IR), proton, and carbon‐13 nuclear magnetic resonance (NMR) as well as DEPT techniques. The polyelectrolytes were used to detect the antibodies of red blood cells (RBCs) in human sera and the results were compared with hexadimethrine bromide (polybrene), bromeline, and other methods. This article presents data supporting the use of the manual poly(DMDAAC) test; the 1‐min procedure at room temperature provided a rapid and sensitive test. The states of agglutination of RBCs were investigated by transmission electron microscopy (TEM). The results of the morphology were in agreement with the manual poly(DMDAAC) test. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 87: 1957–1961, 2003     

The electrochemistry of nitrate-amide melts: Reactions of nickel and copper in nitrate-amide melts

Copper and nickel may be electrodeposited from their ions in solution in nitrate-amide melts at room temperature. In the ammonium nitrate-acetamide-urea melt at 23°C, the reduction to the metal competes with the corrosion reaction at low rates and with the reduction of the ammonium and nitrate ions of the melt at high current densities. Two distinct types of nickel complexes are found in solution. The nickel complex formed by the corrosion reaction is bound by at least one ammonia ligand. Nickel complexes formed by dissolving the halide in the melt show evidence of coordination by less strongly bounding ligands, probably by amides. Similarly, the visible spectra of copper chloride in solution suggest that the cupric ions are coordinated primarily by amides. The copper corrosion reaction produces a complex with a spectra distinctly different from that of cupric chloride in solution. The shift in absorption maxima suggests that the copper complex formed by the corrosion reaction has at least one ammonia ligand in the coordination sphere.     

原料中添加天然黏土室温合成介孔分子筛

室温条件下以天然黏土、硅酸钠和氯化铝为原料,十六烷基三甲基溴化铵(CTAB)为模板剂合成介孔分子筛。用XRD,TEM,FT-IR和N₂物理吸附等手段对所合成的样品进行表征。结果表明：室温条件下添加天然黏土成功合成出介孔分子筛,其比表面积为902 m²·g^-1,平均孔径为3.97 nm。经750℃下焙烧3 h后,样品的比表面积降低,但介孔结构依然存在。在100℃下水热处理15 d后比表面积为776.78 m²·g^-1,平均孔径为4.34 nm,表明添加天然黏土室温下合成出的介孔分子筛具有高的热稳定性和水热稳定性。     

Spectrokinetics study of probable effects of diverse inorganic ions on bleaching of dye

Toluidine blue (TB) is an important anticoagulant metachromasia molecule showing a pronounced variation in the visible spectrum due to the aggregation phenomenon and electrostatic interaction with the charged synthetic and biologic polymers. The current study describes the interactive role of diverse inorganic material ions on the bleaching of toluidine blue (tolonium chloride) (TB⁺) with urea in acidic and basic media using the spectrophotometric technique. The spectra of TB and urea with different cations and anions were monitored and their characteristic features are presented here. The negative effect of added cations on reduction may be the result of altered electron pathways which led to suppression of the reduction/bleaching of TB, while a slight decrease in dye reduction by added anions may be due to the scavenging of the OH* radical. It has been observed in the case of Co²⁺ that in addition to the electron-transfer reaction, other processes like layer and precipitate formation also appear to be taking place. The dye bleaching process followed pseudo first order kinetics with respect to TB, urea, and H⁺ ion, whereas significant decoloration in the presence of urea proved that reductants control the redox reaction. No decoloration in acidic medium with diverse ions was seen compared to alkaline media, showing that water pH played an important role in the bleaching of dye. The reduction/bleaching of dye was investigated at different temperatures, and energy parameters were evaluated for a TB⁺-Urea reaction, including the energy of activation (E_a = 39.60 kJ·mol^-1), enthalpy of activation (?H^# = 34?kJ·mol^-1), entropy of activation (?S^# = 146.5 kJ mol^-1·K^-1), and free energy of activation (ΔG* = -52.35 kJ·mol^-1). A mechanism of interaction of diverse ions in dye bleaching and a mechanism of reduction based on the above findings is proposed.     

铝在含锂盐的碱性溶液中稳定性的研究

为了解铝在锂盐溶液中的钝化行为,通过失重法研究了溶液pH值、温度、浸泡时间及氯离子浓度等因素对钝化膜形成及稳定性的影响。结果表明,溶液pH值和温度对钝化膜的和稳定性影响最大。为获得稳定的钝化膜,锂离子的浓度应随pH值的增大而增大,含锂钝化膜对氯离子的局部腐蚀有较强的抑制作用。     

一种含氟丙烯酸酯单体的合成与表征

首先以甲基丙烯酸与草酰氯室温反应3h得到甲基丙烯酰氯(Ⅰ);在三乙胺催化下,将Ⅰ与乙醇胺0℃反应5h,室温反应20h得到羟乙基甲基丙烯酰胺(Ⅱ)。全氟辛酸经酰氯化,再与Ⅱ于室温反应46h,成功制得含全氟基团的丙烯酸酯单体——全氟辛酸甲基丙烯酰胺基乙酯。探讨了各步反应的主要影响因素,并用FTIR、MS、13CNMR等对产物的化学结构进行了表征。     

Aliphatic poly(oxytetramethylene) ionenes: effect of counter-anion on the properties and morphology

Effect of counter-anion on the properties and morphology of aliphatic poly(oxytetramethylene) ionenes was investigated, and the relationship between the properties and morphology was elucidated. The ionenes possess elastic properties at low elongations whereas they predominantly exhibit a plastic deformation at high elongations. The morphology of the ionenes was analysed in the nanometer scale by fitting a cascade model for randomly branched f-functional polycondensates incorporated in Debye-Bueche random-two-phase model and the interference term by the interdomain interaction on their small-angle X-ray scattering profiles. The size of ionic domains and distance between the domains were smaller and shorter in the ionene with bromide counter-anion than those in the ionene with chloride counter-anion, respectively. The formation of crystallite of poly(oxytetramethylene) (POTM) segments was detected in the ionene with chloride counter-anion at room temperature. These characteristics of aliphatic POTM ionenes gave the difference in their mechanical and thermal properties.