漂白过程的电化学研究：Ⅰ.Fe（Ⅲ）EDTA氧化金属银的反应动力学

在卤离子存在下,Fe(Ⅲ)络合物与金属银之间的氧化还原反应,可用氧化形成的卤化银的电化学还原时间τ进行测定。本工作用银旋转圆盘电极研究了在改变氧化时间,反应物浓度和电极旋转速度的情况下,Fe(Ⅲ)络合物与金属银之间反应动力学,并测定了形成溴化银的初始速率与pH的关系。 该氧化还原反应是扩散控制反应,对于Fe(Ⅲ)EDTA和卤离子来说均为一级反应。Fe(Ⅲ)EDTA在水溶液中的扩散系数可由极限电流与Fe(Ⅲ)EDTA的浓度和银旋转圆盘电极的旋转速度的平方根之间的关系求算出来。     

漂白过程的电化学研究——Ⅱ.碘离子对Fe(Ⅲ)络合物氧化金属银反应的影响

当溶液中含有溴化物时,Fe(Ⅲ)络合物与银电极之间的反应较慢。如果使用碘化物、反应会加快。电流加和原理和溶度积常数可用来解释碘化物对Fe(Ⅲ)络合物氧化金属银反应加速作用机理。在电极表面上氧化形成的AgI较之溴化银更难用硫代硫酸盐络合除去。 在含有Fe(Ⅲ)络合物的溴化物和碘化物混合溶液中,卤化银在银电极表面上的生成速率随溶液中碘化物浓度的增大先是下降,然后上升。因为AgI较低的溶度积常数,AgI/Ag的阳极化曲线与Fe(Ⅲ)络合物/Fe(Ⅱ)络合物氧化还原对的阴极化曲线间较负的混合电位,在浸入含有少量碘化物和一定浓度溴化物的Fe(Ⅲ)络合物溶液的银电极表面上,优先生成AgI。     

新化学法制镜

<正> 德国化学家多伦(Bernhard Tollen's)于1882年用硝酸银氨溶液来鉴别醛和酮的试剂,故称多伦试剂。由于反应时试剂与醛作用,使银氨络离子还原成金属银附着在玻璃壁上形成银镜,又称银镜反应,因此是化学法制镜的基础。银镜反应是利用银氨络离子的氧化性,使具有还原性的醛、肼、葡萄糖以及酒石酸等物质,还原生成金属银的反应。实际上是一种氧化还原反应。工业上利用该反应制取保     

Mechanism and kinetics analysis of the phenol degradation by Fe(Ⅱ)-EDTA/K2S2O8 process

考察了Fe(Ⅱ)-EDTA/K2S2O8体系降解苯酚的影响因素,并对体系中苯酚的降解机理和反应动力学进行了初步分析。结果表明,铁离子、氧化剂形态以及紫外光辐照、螯合剂的存在对氧化体系作用效果影响显著。EDTA剂量为0.5 mmol/L、Fe(Ⅱ)剂量为1.0 mmol/L、K2S2O8剂量为2.0 mmol/L、溶液初始pH值为7.0、温度为60 ℃的条件下反应60 min,浓度为100 mg/L的苯酚降解率为71.48%,同样条件下紫外光辐照时降解率可达89.38%。降解机理与动力学分析表明,苯酚在Fe(Ⅱ)-EDTA/K2S2O8体系中降解途径以与Fe4+络合降解为主。     

Fe（Ⅱ）-EDTA/K2S2O8降解苯酚及反应动力学分析

考察了Fe(Ⅱ)-EDTA/K2S2O8体系降解苯酚的影响因素,并对体系中苯酚的降解机理和反应动力学进行了初步分析。结果表明,铁离子、氧化剂形态以及紫外光辐照、螯合剂的存在对氧化体系作用效果影响显著。EDTA剂量为0.5 mmol/L、Fe(Ⅱ)剂量为1.0 mmol/L、K2S2O8剂量为2.0 mmol/L、溶液初始pH值为7.0、温度为60℃的条件下反应60 min,浓度为100 mg/L的苯酚降解率为71.48%,同样条件下紫外光辐照时降解率可达89.38%。降解机理与动力学分析表明,苯酚在Fe(Ⅱ)-EDTA/K2S2O8体系中降解途径以与Fe4+络合降解为主。     

固体聚合硫酸铁的合成及基本性能研究

本文讨论了Fe~( )离子在酸性条件下的催化氧化反应,指出制备固体聚合硫酸铁的关键是控制反应温度和∑SO_4~(2-)/∑Fe的摩尔比。本文根据浊度、pH值、无机离子等因素研究了固体聚合硫酸铁的絮凝性能;本文还对固体聚合硫酸铁的絮凝机理进行了探讨。     

浸金体系中影响硫脲消耗因素的研究

本文测定厂硫化矿及其氧化焙破对硫脲的吸附，空气对硫脲的氧化，以及Fe（Ⅲ）离子作氢化剂时，浮选剂黄药、起泡剂松节油、硫化矿和焙砂对硫豚稳定性的影响．研究结果表明：硫化矿及焙砂对硫脲部有吸附作用；空气的氧化亦不容忽视；硫化矿和培砂对硫脲－Fe（Ⅲ）离子之间的氧化还原反应均表现出显著的催化作用，而浮选药剂则几乎没有影响．在浸取体系中，各有过量的Fe（Ⅲ）离子，硫脲很不稳定，迅速被氧化而分解，相应的Fe（Ⅲ）离子绝大部分转化为Fe（Ⅱ），浸液电位随之下降．存在培砂时，体系相对稳定电位是245mV；存在硫化矿时，电位是235mV如果浸取操作电位高于上述指标，将导致较高的硫肥消耗     

乙二胺四乙酸铁络合物湿法络合脱硝液的再生研究进展

近年来,面对大气污染日益严峻的现状,用于燃煤烟气中氮氧化物减排控制技术的研发显得尤为关键。乙二胺四乙酸铁络合物（Fe （Ⅱ） EDTA）络合脱硝法由于吸收速率快、络合容量大以及可应用于脱硫被广泛研究。但是Fe （Ⅱ） EDTA易被氧气氧化为Fe （Ⅲ） EDTA,从而失去对氮氧化物的络合能力,因此为了提高Fe （Ⅱ） EDTA脱硝效率,Fe （Ⅱ） EDTA再生十分必要。本文综述了Fe （Ⅱ） EDTA再生技术,详细介绍了含硫化合物、金属粉末、尿素、有机物、催化剂以及微生物再生Fe （Ⅱ） EDTA的原理,并阐述了各种再生技术的技术特点,指出了各种再生方法的优势与不足,并对各种再生技术工业化现状进行了分析。最后指出微生物再生Fe （Ⅱ） EDTA是前景较好的再生技术,研究好氧微生物菌种再生Fe （Ⅱ） EDTA以及微生物再生Fe （Ⅱ） EDTA的设备,发展一套高效的微生物再生Fe （Ⅱ） EDTA与湿法脱硝一体化吸收工艺,是再生Fe （Ⅱ） EDTA技术未来的发展方向。     

石墨烯负载银的合成研究

为改善石墨烯加工性能,在石墨烯掺杂金属银。以低成本可膨胀石墨粉为原料,利用氧化还原反应在氧化石墨烯上负载银,确定了该合成反应的工艺条件。X射线衍射、红外光谱分析、拉曼光谱、紫外可见分光光度分析、扫描电子镜等手段对氧化石墨烯负载银的内部结构进行表征。结果显示:改性后的氧化石墨烯热稳定性更好,加工性能更加优越。石墨烯负载银电化学性能的伏安循环法实验揭示,石墨烯负载银具有更优良的电学性能。     

新型羟肟酸螯合树脂的合成及应用

采用对氨基水杨酸(PASA)与氯甲基化交联聚苯乙烯(CMPS)微球表面的苄氯基团在DMF溶液中发生亲核取代反应,制得了氨基水杨酸-交联聚苯乙烯(ASA-CPS)螯合树脂。然后用甲醇对ASA-CPS微球进行酯化,再对酯化产物进行胺化,制得了羟肟酸-交联聚苯乙烯(AHA-CPS)螯合树脂。考查了主要反应条件对取代反应的影响,初步试验了ASA-CPS和AHA-CPS对Fe(Ⅲ)离子的螯合性能。结果表明,ASA-CPS对Fe(Ⅲ)离子具有一定的螯合能力,吸附容量达4.21 mmol/g;AHA-CPS与ASA-CPS相比具有更好的螯合能力,对Fe(Ⅲ)离子吸附容量达15.44 mmol/g。     

Electrochemical Recognition of Metalloproteins by Bromide-modified Silver Electrode - A New Method

A bromide–modified silver electrode is reported, in the present study, to catalyze the redox reactions of metalloproteins. This study describes that the bromide ions show very good redox behavior with silver electrode. The cathodic and anodic peak potentials were related to the concentration of bromide ions involved in making bromide-modified silver electrode. The electrode reaction in the bromine solution was a diffusion-controlled process. Positive potential shift of the bromide ions was seen when different proteins were added to the solution using a silver electrode. New cathodic and anodic peaks were observed at different potential ranges for myoglobin, cytochrome c and catalase. A linearly increasing cathodic peak current of bromide ions was seen when the concentration of superoxide dismutase was increased in the test solution. However, no change for albumin was observed when its concentration was increased in the test solution. Present data proves our methodology as an easy-to-use analysis for comparing the redox potentials of different metalloproteins and differentiating the metallo-from non-metalloproteins. In this study, we introduced an interesting method for bio-electrochemical analyses.     

Reduction of Fe(II)EDTA‐NO using Paracoccus denitrificans and changes of Fe(II)EDTA in the system

BACKGROUND: In the BioDeNO_X technology for NO_X removal from flue gas, bioreduction of Fe(II)EDTA‐NO and Fe(III)EDTA are core processes. In this study, a newly isolated strain, Paracoccus denitrificans, was used to reduce Fe(II)EDTA‐NO with glucose and Fe(II)EDTA as donor electrons. To better understand the change law of Fe(II)EDTA, the process of Fe(II)EDTA‐NO reduction by P. denitrificans with glucose and Fe(II)EDTA as electron donors was investigated, and the factors that might affect Fe(II)EDTA concentration were studied. RESULTS: For the bioreduction process of Fe(II)EDTA‐NO, P. denitrificans could use glucose and Fe(II)EDTA as electron donors. At different stages, primary electron donors were different, thereby affecting the concentration of Fe(II)EDTA in the system. It was also proved that this strain not only reduced Fe(III)EDTA with glucose as the electron donor but also secreted several substances that reacted with Fe(III)EDTA, resulting in increased Fe(II)EDTA concentration in the solution. CONCLUSIONS: This work has shown that P. denitrificans can reduce Fe(II)EDTA‐NO and Fe(III)EDTA simultaneously to regenerate NO_X absorption solution. © 2012 Society of Chemical Industry     

Electroless versus electrodriven deposition of silver crystals in polyaniline: Role of silver anion complexes

Electrocrystallization of silver is studied at polyaniline-coated electrodes using silver cations and two silver anion complexes (silver thiosulfate and silver–EDTA) as reducing species. Use of the silver thiosulfate complex results in a significant shift of the silver deposition potential window in the negative direction and highly impeded metal crystallization. The silver cation and silver–EDTA plating solutions allow to perform both electrodriven and electroless metal deposition. Number and size of silver crystals obtained by the two deposition methods in the different plating solutions are compared. Electroless precipitation in the silver–EDTA solution results in the highest number (10⁸ cm⁻²) of small-sized crystals. This result is discussed in terms of the special role of the EDTA anions for the redox state of the polyaniline layers. It is demonstrated that factors such as polyaniline redox charge, concentration of reducing ions and dipping time allow effective control over the amount of electroless deposited metal.     

A study of the Fe(III)/Fe(II)-triethanolamine complex redox couple for redox flow battery application

The electrochemical behavior of the Fe(III)/Fe(II)-triethanolamine(TEA) complex redox couple in alkaline medium and influence of the concentration of TEA were investigated. A change of the concentration of TEA mainly produces the following two results. (1) With an increase of the concentration of TEA, the solubility of the Fe(III)-TEA can be increased to 0.6 M, and the solubility of the Fe(II)-TEA is up to 0.4 M. (2) In high concentration of TEA with the ratio of TEA to NaOH ranging from 1 to 6, side reaction peaks on the cathodic main reaction of the Fe(III)-TEA complex at low scan rate can be minimized. The electrode process of Fe(III)-TEA/Fe(II)-TEA is electrochemically reversible with higher reaction rate constant than the uncomplexed species. Constant current charge-discharge shows that applying anodic active materials of relatively high concentrations facilitates the improvement of cell performance. The open-circuit voltage of the Fe-TEA/Br₂ cell with the Fe(III)-TEA of 0.4 M, after full charging, is nearly 2.0 V and is about 32% higher than that of the all-vanadium batteries, together with the energy efficiency of approximately 70%. The preliminary exploration shows that the Fe(III)-TEA/Fe(II)-TEA couple is electrochemically promising as negative redox couple for redox flow battery (RFB) application.     

An indirect electrochemical process for the removal of NOx from industrial waste gases

The development of a new electrochemical process for the absorption of NOx from industrial waste gases is described. Conversion of NO was performed by an indirect outer cell process using dithionite as the redox mediator and Fe(II)EDTA as the complexing agent. The absorption process, involving complex formation with Fe(II)EDTA in the absence and presence of dithionite, was investigated using a packed bubble column. In semibatch experiments the dependence of different system parameters on the degree of NO conversion was studied: concentration of dithionite and Fe(II)EDTA, gas flow rate, oxygen content, and temperature. The reaction products in the gas phase and in the liquid phase were analyzed using gas chromatography and ion chromatography, respectively. This analysis proved that, instead of N2 or N2O, ammonia and amidosulfonic acid are the main reaction products in the solution. The kinetics and the conditions for the regeneration of dithionite by electrochemical reduction of sulfite were studied on RDE and by experiments in a divided cell. For the dithionite production a current efficiency of about 80% was found in 0.2 m Na2SO4 at pH 5.6. By combining the chemical NO absorption in a gas/liquid contactor with the electrochemical regeneration of dithionite in a divided plate and frame cell a degree of NO conversion better than 90% under continuous operation can be obtained.     

新型中空卤化银颗粒乳剂的制备和性能研究 Ⅳ.利用非水溶剂制备中空卤化银颗粒乳剂

有近１６０年历史的银盐卤化银乳剂制备的感光材料，到目前为止仍不失为一种优良的信息记录材料．但昂贵的白银的缺乏和消耗，使得节银和降低成本成为银盐感光材料生产中急需要解决的问题．另一方面在感光材料的制备和使用过程中，绝大部分过程（如化学增感、光谱增感、潜...     

冠醚化合物在制备外延卤化银乳剂中的作用

自从冠醚于六十年代末问世以来,科学家们对它进行了大量的研究。它以遮盖力大,对金属离子络合性能好而著称于化学领域。在感光化学领域,它的主要应用在于对乳剂晶体的尺寸及分布产生影响,使之均一,且颗粒增大;作为调变剂,促进外延乳剂晶体的生长;提高乳剂的感光性能。     

Studies on cerium oxidation in catalytic ozonation process: A novel approach for organic mineralization

A novel regenerative catalytic system has been developed using cerium and ozone in nitric acid medium. It was found that cerium(III) was oxidized to cerium(IV) by ozone in nitric acid medium with good conversion yields. The conversion rate of Ce(III) was measured under various parameters viz. ozone–air flow rate, initial concentration of Ce(III), and concentration of nitric acid at 25 °C. It was found that the conversion of Ce(III) increased with increasing ozone flow rate and concentration of nitric acid while decreased with increasing Ce(III) concentration. The pseudo first order kinetic constants were evaluated for Ce(III) oxidation. The efficiency of this hybrid system comprising of ozone and cerium redox pair towards organic mineralization was evaluated taking phenol as the model organic pollutant and compared with Ce(III) catalyzed and uncatalyzed ozonation processes. The presence of Ce(III) catalyst increased the destruction efficiency of phenol compared to uncatalyzed ozonation whereas a synergetic effect was observed between the cerium redox pair (Ce(III) and Ce(IV)) and ozone towards phenol mineralization and a maximum TOC removal was obtained in the latter case. Kinetic interpretations have been made with some simplifying assumptions owing to the much complex nature of ozone and metal ion interactions. This hybrid catalytic ozonation process may find its suitability for continuous organic destruction at room temperature.     

Fe(Ⅲ)-EDTA吸收羰基硫动力学研究

<正>在合成氨原料气中,羰基硫(COS)占有机硫的80%左右,天然气中COS亦高达500ppm,为了经济有效地脱除COS,作者经过筛选实验发现乙二胺四乙酸络合铁(Fe(Ⅲ)-EDTA)可以脱除COS,故对Fe(Ⅲ)-EDTA吸收COS的动力学进行了研究,揭示了该过程的控制步骤,建立了其数学模型,并提出了对该方法进行改进的可行性方案.     

国际影像公司中国专利申请分析报告(一)

21世纪是影像业快速向数字化、网络化发展的时代。传统影像材料公司、影像器材生产商和IT企业纷纷汇集于这一极具发展前景的产业,竞争日益激烈,其中面对中国市场,各大公司都寄予厚望。对国际大公司申请的中国专利情况进行跟踪分析,有助于我们及时掌握国内技术和市场的发展动向,开阔思路,激发创新灵感。本次分析报告针对惠普、佳能、富士、柯达、精工爱普生、柯尼卡美能达、爱克发和三菱制纸八家公司,统计了公开日从2001年至2005年6月的近9000件中国专利。报告主要分为3个部分:(1)通过对比各公司在全球、本国和中国的专利数据,从侧面了解各公司的经济实力、技术创新能力、对外发展战略、对中国市场的定位以及对中国市场创新性技术投入的策略;(2)对各公司的专利数据按照所属技术领域进行归纳和分析,详细分析各公司近年来中国专利技术的全貌、重点技术领域、最新发展动向以及采取的专利策略;(3)对各公司中国专利涉及的主要技术领域作简要的横向对比,由此从产业全景角度,发现重点领域,挖掘空白领域,并提出有关未来技术发展和专利工作的一些建议。