可见光促进对称型芳香偶氮类化合物的合成

以芳香胺为原料，室温下，氧气为氧化剂，可见光促进芳香胺合成对称型芳香偶氮类化合物，收率最高可达98%。运用1HNMR和13CNMR对产物进行了结构表征。该方法具有条件温和、高效和清洁等优点。     

微生物降解偶氮染料的研究进展

偶氮染料广泛应用于纺织印染、造纸印刷等行业,产生的染料废水严重污染环境。近年来,利用微生物(细菌、真菌、藻类)对偶氮染料进行脱色降解的研究报道很多。介绍了最近几年染料废水脱色降解研究中涉及到的微生物,并探讨了相关微生物对偶氮染料的脱色降解作用及其机理,旨在为运用微生物对偶氮染料废水进行脱色处理和降解研究提供参考和依据。     

Electrosynthesis of conducting polymer films from the azo dye methoxy red

Anodic polymerization of the azo dye methoxy red (4-methoxybenzene azo-1,3-diaminobenzene) on platinum electrodes in 1 M HCl in 50% v/v ethanol/water was found to yield thin and stable polymeric films. The films were electroactive in acidic solutions and the activity diminished as the acidity decreased. The pair of symmetrical redox peaks at a formal redox potential, (E )_pH=0 = 0.61 V vs SCE, with a Nernstian slope dE/dpH = 0.06 V, is attributed to a 1:1 proton + electron elimination (on oxidation)/addition (on reduction) at the amino/imino linkages which connect the aromatic nuclei. Chronocoulometric plots indicated that the transport of the solvated protons, and probably Cl^– ions, through the film is the rate-determining step of the above redox processes. The rate of electron transfer reactions of the redox couple [Fe(CN)₆]^3–/4– on poly-methoxy red-covered platinum electrodes decreased by a factor of more than two orders of magnitude, compared to the bare electrodes.     

某些变色酸偶氮类染料与蛋白质作用的分光光度研究

用分光光度法研究并比较了１０种变色酸偶氮染料（偶氮胂Ⅰ、偶氮胂Ⅲ、偶氮氯膦Ⅰ、偶氮氯膦Ⅲ、氨基Ｃ酸偶氮胂、氨基Ｇ酸偶氮氯膦、邻溴偶氮氯膦、间碘偶氮氯膦、二溴乙氧基偶氮氯膦、邻溴偶氮胂）与蛋白质的作用及所引起的光谱性能变化。详细探讨了染料结构、缓冲条件、种类及酸度对染料与蛋白质作用的影响,用双波长法测定了最大结合数及结合常数。     

Thermal explosion in Ti + 3Al mixture: Mechanism of phase formation

Synthesis of TiAl₃ from Ti + 3Al powder mixtures in thermal explosion mode was found to proceed by the equilibrium mechanism in case of smaller Ti particles (55 μm) and by the non-equilibrium mechanism in case of larger Ti particles (130 μm). In the latter case, the product was found to contain the phases of TiAl₃, TiAl, Ti₃Al, Ti-based solid solution, and no unreacted Al.      

Influence of solvents on the photoinduced birefringence in chitosan films incorporating azo dyes

The photoinduced birefringence arising from trans–cis–trans isomerization has been studied in chitosan cast films doped with the azo dye Ponceau‐S. The chitosan/Ponceau‐S films are highly resistant to several solvents, which allowed the study of their optical storage features after immersion in various solvents. We demonstrate that the induced birefringence and its dynamics are influenced by the solvent. From experiments using such different solvents as water, dimethylsulfoxide, ethylene glycol, methanol and chloroform, it was found that the induced birefringence and the writing rate increase linearly with the dielectric constant of the solvent. At high dielectric constant, photoinduced molecular reorientation is facilitated, leading both to a larger birefringence and faster dynamics. Copyright © 2007 Society of Chemical Industry     

Kinetic study on the sunlight-induced degradation of acid azo dyes on silk

The effects of solar irradiation on the two azo dyes CI Acid Red 1 and CI Acid Orange 8 were investigated both on dyed silk and in aqueous solution at pH 2–4.5. When absorbed on silk, the dyes were more photoreactive, both undergoing photodegradation, though at different rates, and displaying a protective action towards the fibre substrate, as evidenced by viscosimetric analysis. In aqueous solution CI Acid Orange 8 underwent photodegradation, with a quantum yield around 10⁻³ mol einstein⁻¹, while the predominant reaction occurring from CI Acid Red 1 was photocyclization, especially at low pH.     

双氰乙基偶氮化合物的合成及表征

用无水AlCl3催化问甲苯胺与丙烯腈的加成反应,合成了偶合组分N,N-二氰乙基间甲苯胺,并分别与重氮组分对硝基苯胺、对硝基邻氯苯胺、2,4-二硝基-6-氯苯胺和2,4-二硝基-6-溴苯胺进行偶合反应,合成了4种双氰乙基偶氮化合物.结果表明,生成的偶氮化合物产率分别为72%、78%、91%和81%,含量均超过96%;而且...     

偶氮染料的光还原脱色及其染色废水的回用研究

用还原脱色剂对水溶性偶氮染料进行光还原脱色降解,重点考察了还原脱色剂、辐射光以及染料浓度等对还原脱色反应的影响,并将脱色后的染色废水回用于棉织物染色中.结果表明,以适当比例的引发剂和促进剂组成的还原脱色剂具有较强的脱色降解能力,辐射光对染料的还原脱色反应具有明显的促进作用,染料浓度的提高不利于染料的脱色降解反应.脱色废水可以回用于棉织物的活性染料染色中,通过降低染色过程中氯化钠和碳酸钠的添加量,可使染色试样与自来水染色试样的总色差(DE*)＜1.0.     

Degradation of disperse azo dyes from waters by solar photoelectro-Fenton

Solutions of the azo dyes Disperse Red 1 (DR1) and Disperse Yellow 3 (DY3), commonly used in the Chilean textile industry, in 0.1 mol dm⁻³ Na₂SO₄ and 0.5 mmol dm⁻³ Fe²⁺ of pH 3.0 were comparatively degraded by electro-Fenton (EF) and solar photoelectro-Fenton (SPEF) using a 2.5 dm³ recirculation flow plant containing a BDD/air-diffusion cell coupled with a solar photoreactor. Organics were oxidized in EF with hydroxyl radicals formed at the anode surface from water oxidation and in the bulk from Fenton's reaction between electrogenerated H₂O₂ and added Fe²⁺. The oxidizing power of SPEF was enhanced by the additional production of hydroxyl radicals from the photolysis of Fe(III) hydrated species and the photodecomposition of Fe(III) complexes with intermediates by UV light of solar irradiation. Total decolorization, complete dye removal and almost overall mineralization for both dye solutions were only achieved using the most potent SPEF process, yielding higher current efficiencies and lower energy consumptions than EF. Final carboxylic acids like pyruvic, acetic, oxalic and oxamic were detected during the SPEF treatments. NO₃⁻ ion was released as inorganic ion. The use of a solution pH of 2.0–3.0 at 50 mA cm⁻² was found preferable for SPEF. Synthetic textile dyeing solutions containing the dyes were treated under these conditions yielding lower decolorization rate, slower dye removal and smaller mineralization degree than only using 0.1 mol dm⁻³ Na₂SO₄ due to the parallel oxidation of organic dyeing components. However, lower energy consumptions were obtained by the destruction of more amounts of total organic carbon, indicating that SPEF is a useful and viable method for the remediation of textile industrial wastewaters with high contents of disperse azo dyes.     

REACH法规中12种偶氮染料的快速测试方法:GC-MSD法

采用气相色谱-质谱联用法(GC-MSD)快速测定纺织品领域中涉及REACH法规的12种偶氮染料.纺织样品在柠檬酸盐缓冲溶液中用连二亚硫酸钠还原分解以产生可能存在的致癌芳香胺,以乙酸乙酯和叔丁基甲基醚(1∶1)混合体系为提取溶剂,机械振荡提取15 min,用GC-MSD测定.该方法测定12种偶氮染料的回收率为58.0％ ～ 104.0％,相对标准偏差小于5％(n=8),测定低限为2.0 mg/kg.阳性样品测定结果表明,该方法准确、简便、快捷.     

厌氧+好氧+煤渣吸附处理偶氮染料废水研究

可生化性试验表明：偶氮染料废水对微生物有抑制作用,但地驯化活性污泥并无明显的抑制作用。废水经过上流式厌氧污泥床（ＵＡＳＢ）的处理,可去除５０％～６０％的ＣＯＤ,处理系统内形成颗粒污染,出水ＢＯＤ５／ＣＯＤ增加到０．４２。厌氧出水经生物接触氧化法处理,可去除６５％ＣＯＤ。再经煤渣吸附,出水ＣＯＤ可降至２００ｍｇ／Ｌ以下,达到污水综合排放标准二级。     

论偶氮染料的偶氮-腙互变异构

偶氮染料存在着偶氮-腙互变异构。其中包括两个概念, 一是偶氮体和腙体是一对异构体, 由其结构不同导致其发色和化学性能不同;二是两种异构体在满足某种条件下可以互变。对偶氮体或腙体结构的识别是研究偶氮染料结构与性能的基础。当前染料学术界和产业界对偶氮-腙互变异构有两大误识:偶氮体即腙体, 两者不必加以区分;以及两者既为互变异构, 则时刻处于变化中而无法进行区分。本文针对上述误识, 讨论了两种异构体的结构与性能关系。一个偶氮染料的偶氮体及醌腙体是两种结构与性能, 如紫外-可见光谱吸收、化学反应性能及牢度不同的化合物。通常仅以某种异构体结构为稳定状态存在, 折中结构结决定了它的颜色和染色性能。两者仅在某种特定的条件下可以互相变化。这些条件取决于化合物结构、所处环境条件, 如温度、溶剂、介质pH等环境因素对偶氮-腙平衡的影响。介绍了用其红外光谱、拉曼光谱、核磁波谱、质谱以及晶体的X衍射谱来确认互变异构体的方法。     

偶氮染料分子结构与脱色性能的定量关系研究

采用臭氧氧化法对30种水溶性偶氮类染料进行脱色处理,运用定量构效关系方法进行染料脱色率研究。通过选择分子结构描述符考察了脱色率及分子结构之间的定量关系,建立了模型方程,并对其进行了检验。结果表明,在染料分子结构描述符与脱色率之间存在着较好的线性相关性,相关系数R2为0.849。得到了分子结构描述符和脱色率之间的定量关系方程,该定量关系方程可以用于计算染料的臭氧氧化法理论脱色率。     

固相反应法合成5-取代-8-羟基喹啉偶氮化合物

以8-羟基喹啉、取代苯胺、亚硝酸钠和硫酸氢钾为原料,室温下经固相反应法合成了系列5-取代-8-羟基喹啉偶氮类化合物.实验结果显示,反应产物收率高低顺序与苯胺取代基团吸电子能力大小顺序相同.实验还考察了亚硝酸钠的用量、取代苯胺与8-羟基喹啉的物料配比等对反应产物收率的影响.结果表明,当氨基(-NH2)、8-羟基喹啉及亚硝...     

Chemical decolorization of the azo dye CI Reactive Orange 96 by various organic/inorganic compounds

Batch experiments were performed to investigate the possibility and kinetics of chemical decolorization of the reactive mono‐azo dye CI Reactive Orange 96 (RO 96) with various compounds such as cysteine, ascorbate, Ti(III)‐citrate, Fe(II)‐sulfate, and yeast extract. Cysteine and ascorbate (10 mmol dm^?3 respectively) decolorized RO 96 (0.19 mmol dm^?3) in the absence of oxygen. Increasing the concentration of either reductant (to 20 or 38 mmol dm^?3) enhanced the decolorization rate, showing first‐order kinetics with respect to both the concentration of the dye and of cysteine or ascorbate. The rate constants, k, for cysteine and ascorbate were 0.0003 and 0.0010 dm³mmol^?1 h^?1 respectively at pH 7.1 and 33 °C. Ti(III)‐citrate (10 mmol dm^?3) decolorized RO 96 (0.20 mmol dm^?3) within 5 min, independent of the presence of oxygen. Fe(II)‐sulfate was not effective in the decolorization of RO 96 at pH 8, whereas a rapid decolorization occurred at pH 12. This study suggests that a variety of abiotic processes may be involved in decolorization under anaerobic conditions. © 2002 Society of Chemical Industry     

Synthesis of azo chromophores by using a polymer‐supported sodium nitrite

Polymer supported reagents especially anion exchange resins have been widely applied in organic synthesis. The recent developments in polymer‐supported reactions have led to the propagation of combinatorial chemistry as a method for the rapid and efficient preparation of novel functionalized molecules. An interesting and fast growing branch of this area is polymer‐supported reagents. In this study, diazonium salts are generated and are coupled with a coupling component by using a polymer supported nitrite and a polymeric acid. In this procedure, the azo chromophores are formed in a clean and efficient manner, the work‐up is easy and yields are high to excellent. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

Anodic oxidation of azo dye C.I. Acid Red 73 by the yttrium-doped Ti/SnO2-Sb electrodes

This work was conducted to study the ability of anodic oxidation of azo dye C.I. Acid Red 73 (AR73) using the yttrium-doped Ti/SnO₂-Sb electrodes. The effects of Sb doping level, yttrium doping level, thermal decomposition temperature and cycle times of dip-coating thermal decomposition on the properties of the electrodes were investigated. The results showed that the excellent electrochemical activity of Ti/SnO₂-Sb-Y electrode can be achieved at a 7∶1 molar ratio of Sn∶Sb and thermal decomposition temperature of 550°C. Moreover when the cycle times of dip-coating and thermal decomposition were up to 10 times, the performance of the electrode tends to be stable. The Ti/SnO₂-Sb electrodes doped with yttrium (0.5 mol-%) showed the most excellent electrochemical activity. In addition, the influences of operating variables, including current density, initial pH, dye concentration and support electrolyte, on the colour removal, chemical oxygen demand (COD) removal and current efficiency were also investigated. Our results confirmed that the current efficiency increased with the concentrations of dye and sodium chloride. Moreover, increasing the current density and the initial pH would reduce the current efficiency.     

Synthesis and properties of novel aziridinyl azo dyes from 2-aminothiophenes—Part 2: Application of some disperse dyes to polyester fibres

A series of yellow to greenish-blue aziridinyl azo dyes and their azo precursors containing a thienyl coupling moiety has been applied to conventional polyester fibre as well as microdenier polyester by high temperature exhaust dyeing. Heat transferability of these dyes onto polyester fibre has also been examined, using conventional heat-transfer printing techniques. The relevant dyeing characteristics, heat transferability, build-up, dyeability on microfibre polyester, washfastness and lightfastness are given. These aziridinyl dyes are reactive to polyester fibres under HT dyeing conditions. Fabrics dyed with aziridinyl dyes are more resistant to solvent extraction than those dyed with conventional dyes. Residual liquors showed only a pale colour when fabric dyed with aziridinyl dyes was dissolved and then precipitated, whereas a coloured polyester precipitate was obtained.