Bromamine Acid Research Articles

Formation of Active Species and Degradation of Bromamine Acid by Gas-liquid Electrical Discharge in Different Atmospheres

Formation of Active Species and Degradation of Bromamine Acid by Gas-liquid Electrical Discharge in Different Atmospheres

Synthesis of Fe3O4@SiO2-Au/Cu magnetic nanoparticles and its efficient catalytic performance for the Ullmann coupling reaction of bromamine acid

Novel magnetic core/shell bimetallic Au/Cu nanoparticles (Fe3O4@SiO2-Au/Cu NPs) were prepared using SiO2-coated iron oxide (Fe3O4@SiO2) as a supported material. The magnetic Fe3O4 colloidal nanocrystal clusters (CNCs) as nano-core were modified with a silica coating for improvement stability and superficial area of the Au-Cu particles. The morphological structure and chemical composition of the Fe3O4@SiO2-Au/Cu NPs were characterized with high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray (EDX) and X-ray photoelectron spectroscopy (XPS) analyses. The Au and Cu NPs were deposited on the SiO2 surface in a highly dense and well dispersed manner with an average size of approximately 5nm. The Fe3O4@SiO2-Au/Cu NPs as magnetic nano-catalysts were applied to the Ullmann coupling reaction of bromamine acid to synthesize 4,4′-diamino-1,1′-dianthraquinonyl-3,3′-disulfonic acid (DAS). The prepared Fe3O4@SiO2-Au/Cu NPs exhibited efficient catalytic activity with higher conversion and selectivity. A bromamine acid conversion of 97.35% and selectivity for DAS of 88.67% were obtained in aqueous medium. The magnetic nano-catalysts can be readily separated from the reaction system and reused. This new nano-catalytic reaction represents a useful and attractive cleaner production system. The new catalyst system has important and potential applications in dye and pigment industry.

Fabrication of silica nanoparticle-supported copper quantum dots and the efficient catalytic Ullmann coupling reaction

Copper quantum dots (Cu-QDs@silica), with a bird's nest-like structure, were synthesized using silica nanoparticles (NPs) as the support materials for use in the Ullmann coupling reaction of bromamine acid. The average size of the QDs is 2.5nm, with a very narrow diameter range between 1.5 and 4.5nm. The Cu-QDs are imbeded inside the framework of the silica bird's nest-like structure with excellent dispersion stability. The Cu-QDs@silica catalyst showed high catalytic activity for the bromamine acid Ullmann reaction. Using water as the medium, the conversion of bromamine acid reached 96.37% when heated to 90°C after 2h.

Degradation of bromamine acid by a heterogeneous Fenton-like catalyst Fe/Mn supported on sepiolite

A heterogeneous Fenton-like catalyst, Fe/Mn supported on sepiolite, was proved to be effective in the degradation of bromamine acid aqueous solution. The catalyst was prepared with a complex sol-gel method using sepiolite as a carrier and citric acid as a complexing agent. The prepared catalyst was characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM), and the results showed that the existence forms of Fe and Mn were γ-Fe2O3 and MnO and they were distributed evenly on the surface of sepiolite. In the degradation of bromamine acid aqueous solution, the catalyst could possess high catalytic activity when the initial pH of the solution ranged between 3 and 11. In addition, the degradation results showed that there was a synergistic effect between Fe and Mn. The inorganic ions inhibited the degradation efficiency in the early reaction period because of the scavenging effects on •OH, but the inhibition effect became weaker with the reaction time because of the fixation of metal ions on sepiolite.

Degradation of bromamine acid by nanoscale zero-valent iron (nZVI) supported on sepiolite

Sepiolite, a natural nano-material, was chosen as a carrier to prepare supported nanoscale zero-valent iron (nZVI). The effects of preparation conditions, including mass ratio of nZVI and activated sepiolite and preparation pH value, on properties of the supported nZVI were investigated. The results showed that the optimal mass ratio of nZVI and sepiolite was 1.12:1 and the optimal pH value was 7. The supported nZVI was characterized by X-ray diffraction (XRD), transmission electron microscope (TEM) and energy dispersive spectrometer (EDS), and furthermore an analogy model of the supported nZVI was set up. Compared with the nZVI itself, the supported nZVI was more stable in air and possessed better water dispersibility, which were beneficial for the degradation of bromamine acid aqueous solution. The degradation characteristics, such as effects of supported nZVI dosage, initial concentration and initial pH value of the solution on the decolorization efficiency were also investigated. The results showed that in an acidic environment the supported nZVI with a dosage of 2 g/L showed high activity in the degradation of bromamine acid with an initial concentration of 1,000 mg/L, and the degree of decolorization could reach up to 98%.

The bromamine acid removal from aqueous solution using electro-Fenton and Fenton systems

The bromamine acid (BA) removal is investigated in the electro-Fenton and Fenton systems. The BA is an important dye intermediate with difficult biodegradation. So removing BA with advanced oxidation processes may provide common information on anthraquinone dye wastewater treatment. BA has a typical quinonoid structure. It means that the degradation of BA may be coupled with a series of quinone–hydroquinone conversion reactions in these two systems. As a result, two distinct degradation processes for BA are shown in the electro-Fenton and Fenton systems. For a Fenton system, the BA degradation is divided into two phases: the BA quickly transforms into a hydroquinone structure (BAH) in the first few minutes probably due to the formation of a ternary HQ–Fe–H2O2 complex, and then the BAH is oxidized by the •OH; While, in the electro-Fenton system, the BAH is not accumulated during its degradation. Fenton reaction is the main reaction in the electro-Fenton system.

Properties of a novel acid dye 1-amino-4-[(6-nitro-2-benzothiazolyl)amino]-9,10-anthraquinone-2-sulfonic acid with anti-UV capability

A novel acid dye acid was synthesized by the condensation reaction between bromamine acid and 2-amino-6-nitrobenzothiazole and its anti-UV protection properties were evaluated. The results showed that silk dyed with this dye had very good ultraviolet radiation protection capability and excellent dyeing performance. The UV-absorption mechanism of this dye was also discussed.

A new method for the preparation of 1-amino-4-bromo-2-anthraquinonesulphonic acid (bromamine acid) directly from anthraquinone

Bromamine acid (1-amino-4-bromo-2-anthraquinonesulphonic acid) is one of the most important intermediates in the synthesis of acid dyes. Apart from quinizarin and leucoquinizarin, more acid dyes have been produced from bromamine acid by replacement of the bromine atom with aryl amino groups than from any other anthraquinone intermediate. This paper presents a new method for the preparation of 1-amino-4-bromo-2-anthraquinonesulphonic acid in high yield and good quality economically. In most of the methods of nitration of anthraquinone, about 30% anthraquinone is converted to by-product such as dinitroanthraquinones which can be separated only with great difficulty and used as a reagent of reaction and in the end must be discarded and these methods are not economical. Due to the formation of about 35–45% 1-nitroanthraquinone, diffusion of product such as 1-nitroanthraquinone in solvent of nitration is more than anthraquinone, consequently 1-nitroanthraquinone is quickly nitrated from anthraquinone, and the factor of diffusion in nitration is very important. With due attention to analyses of formation of nitroanthraquinones from anthraquinone which are obtainable by high pressure chromatography and from Ref. [Hohmann Walter, Wunderlich Klaus. Process for the mononitration of anthraquinone. U.S.Pat. 4203885; May 20, 1980], nitration of anthraquinone is stopped in about 35–45% conversion of anthraquinone to 1-nitroanthraquinone because the formation of by-product at this point is minimal, and at the end of manufacture of bromamine acid, the unreacted anthraquinone is returned to step of nitration.

Reduction of COD and color of acid and reactive dyestuff wastewater using ozone

Wastewaters obtained from bromamine acid dye and reactive dye manufacturing were treated by ozone bubbling in a cylindrical batch reactor for the purpose of reducing COD to below 150 mg/L, which is the environmental discharge standard of the Republic of Korea. Remarkable COD reduction and decolorization were observed at pH over 11. High inlet gas flowrate and high concentration of ozone gave better results. Little precipitation was observed under the conditions of remarkable COD reduction. At pH of 11, 15 LPM of inlet gas flowrate and 89.3 g/Nm3 of ozone flowrate, the COD of bromamine acid dyestuff wastewater was reduced to 95 mg/L after 90 minutes, and the COD of reactive dyestuff wastewater was reduced to 120 mg/L after 120 minutes. Decolorization was completed after 30 minutes of reaction.

The decolorization of bromamine acid by flavobacterium sp. bx26

The specific strain, Flavobacterium sp. BX26, was examined to decolorize bromamine acid, which is an important intermediate for the synthesis of anthraquinone dyes. The results showed that Flavobacterium sp. BX26 had a high capacity to decolorize bromamin acid within a relatively short time. The decolorization was an inductive process. Flavobacterium sp. BX26 cannot use bromamine acid for growth, but its metabolic intermediates were. It was found that the decolorizing process mainly took place outside the cells or the functional enzymes might be extracellular enzymes. Some factors including salinity, heavy metal ions, complexing agent like EDTA, and the lack of oxygen can seriously inhibit the decolorization process.

The influence of methyl groups on the colour and dyeing properties of acid dyes derived from 1-amino-4-bromo-anthraquinone-2-sulphonic acid and arylamines

Four blue acid dyes were synthesized by condensation of bromamine acid with aniline, 2,4-dimethylaniline, 2,6-dimethylaniline and 2,4,6-trimethylaniline. It was found that the number and orientation of the methyl groups on the 4-phenylamino substituent affected both the colour and dyeing properties of the dyes. The more methyl groups present, the higher was the dye uptake and the better the fastness to wet treatments. When a methyl group is present in the ortho position of the phenylamino group, the hue of the dyes is hypsochromically shifted.

ChemInform Abstract: Synthesis of 2,4‐Diarylureido‐6‐(9‐oxoceramidin‐8‐ylamino)‐s‐triazine Derivatives.

AbstractThe disperse dyes (IX) are prepared from bromamine acid (I) via coupling with aniline (II) and desulfonation to give 1‐amino‐4‐anilinoanthraquinone (IV).

ChemInform Abstract: Synthesis of a Blue Monomeric Dye from Bromamine Acid and 4,4′‐Diaminodiphenylmethane.

ChemInform Abstract: Synthesis of a Blue Monomeric Dye from Bromamine Acid and 4,4′‐Diaminodiphenylmethane.