The dyeing of poly(lactic acid) fibres with disperse dyes using ultrasound: Part 1 - Initial studies

Six disperse dyes were applied at 0.5%, 1% and 2% omf depths of shade to poly(lactic acid) fabric at 30-80 °C for 20, 50 and 90 min in both the presence and absence of ultrasound. Whilst ultrasound enhanced the colour strength obtained for three of the six disperse dyes used at temperatures upto 70 °C, ultrasound did not always result in enhanced colour strength being achieved in the case of the three other dyes. The observed intensification of colour strength was attributed to dye disaggregation. Dyeing at 80 °C in the presence of ultrasound resulted in pale, dull dyeings of reduced colour strength, which was attributed to breakdown of the dye dispersions at this particular temperature.     

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.     

The comb-like modified styrene-maleic anhydride copolymer dispersant for disperse dyes

The comb-like styrene-maleic anhydride copolymer-g-isatoic anhydride-methoxypolyethylene glycols condensate (SMA-g-IA-MPEG) was synthesized by transesterification and amidation reaction. The chemical structure of SMA-g-IA-MPEG was characterized by FTIR and ¹H-NMR. The comb-like modified SMA was first employed as the dispersant of disperse dyes suspension in this paper. The addition of SMA-g-IA-MPEG dispersant improved the dispersibility and stability of the disperse dyes suspension observably due to the steric hindrance and electrostatic repulsion on the surface of dye particles. The impacts of the length of side chains on the particle size, Zeta potential, centrifugal stability, and temperature sensitivity of disperse dyes suspensions were particularly discussed. The results showed that SMA-g-IA-MPEG with moderate length of side chain had the best dispersibility for disperse dyes suspension and the average particle size of dyes can be reduced to 356.1 nm. Thus, the comb-like dispersants played a vital role in dispersing of disperse dyes. © 2018 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019 , 136, 47330.     

Excited-state nature in benzodifuranone dyes: Insights from ab initio simulations

Using ab initio theoretical tools simultaneously accounting for electron correlation and environmental effects, we have simulated the optical spectra of benzodifuranone dyes. In a first step, a valuable computational protocol has been defined and it turned out that a PCM-TD-M06-2X/6-311+G(2d,p)//PCM-PBE0/6-311G(d,p) approach provides an adequate balance between computational requirements and accuracy (deviations of ca. 10 nm with respect to experiment). In a second stage, we have calculated the spectrum of a large series of push-pull structures, and it turned out that the benzodifuranone core is a strong electron capturing group at the excited-state. Indeed, strong auxochroms like the nitro and cyano groups fall short to significantly perturb the LUMO of this series of chromogens. Eventually, in a last phase, the implications of these results are discussed for a series of organic dyes of potential interest for solar cells (DSSC).     

The photoelectrocatalytic oxidative treatment of textile wastewater containing disperse dyes

This paper presents a study of a prospective photoeletrocatalytic oxidation treatment system for disperse dyes obtained from a textile industry. The process utilizes titanium dioxide thin-film electrodes prepared by the sol-gel method as a photo-oxidative anode. Using UV irradiation and an applied potential of + 1.0 V on the nanoporous photoanode of Ti/TiO₂ it is possible to reach a reduction of color removal of 90%, 94% and 100% and 63%, 45% and 61% for TOC removal of DOD, DRD and DRR dyes. The method has been successfully applied to treat textile industry effluent collected at different steps in the industrial process namely before and after conventional wastewater treatment. The results were satisfactory for both effluent samples, leading to a reduction from 52.6% to 69.0% of COD, a diminishing of 80-89% of discoloration and a removal of TOC in the range of 47 to 50%.     

The wash-off of dyeings using interstitial water: Part 3. Disperse dyes on polyester

Poly(ethylene terephthalate), which had been dyed at 0.5, 1.0 and 2.0% omf depths of shade using three disperse dyes, was reduction cleared using a traditional, four-stage process that comprised two water rinses at 40 °C, treatment with aq Na₂CO₃/Na₂S₂O₄ at 60 °C and one cold water rinse. A novel, two-stage wash-off method was also employed that consisted of treatment with damp nylon beads and surfactant at 70 °C and one cold water rinse. In terms of fastness to repeated washing at 60 °C and colorimetric characteristics, the traditional, four-stage reduction clearing treatment using aq., alkaline Na₂S₂O₄ could be replaced by the two-stage, bead wash-off with detergent at 70 °C. As the detergent-based, bead wash-off process used lower amounts of water than reduction clearing and did not employ sodium dithionite, it avoided the environmentally unacceptable generation of aromatic amines in the case of the reduction clearing of azo dyes. Calculations indicated that considerably less heat energy was consumed in bead wash-off than reduction clearing not only because two, rather than four stages were involved but also since the bead process used only a 2:1 water:fibre ratio rather than the 20:1 liquor ratio employed in the reduction clear process; also, the much lower specific heat capacity of nylon than water meant that much less heat was required to heat the beads. The beads adsorbed vagrant disperse dye during wash-off, thereby offering the potential of a lower effluent load compared to a traditional reduction clearing treatment for disperse dyes on polyester.     

Solubility prediction of disperse dyes in supercritical carbon dioxide and ethanol as co-solvent using neural network

Nowadays artificial neural networks(ANNs) with strong ability have been applied widely for prediction of nonlinear phenomenon. In this work an optimized ANN with 7 inputs that consist of temperature, pressure, critical temperature, critical pressure, density, molecular weight and acentric factor has been used for solubility prediction of three disperse dyes in supercritical carbon dioxide(SC-CO2) and ethanol as co-solvent. It was shown how a multi-layer perceptron network can be trained to represent the solubility of disperse dyes in SC-CO2. Numeric Sensitivity Analysis and Garson equation were utilized to find out the degree of effectiveness of different input variables on the efficiency of the proposed model. Results showed that our proposed ANN model has correlation coefficient, Nash–Sutcliffe model efficiency coefficient and discrepancy ratio about 0.998, 0.992, and 1.053 respectively.     

Extended conjugation in di- and tri- arylmethane dyes. Part 3. The effects of increased planarity in Victoria Blue dyes

The synthesis of novel derivatives of the Victoria Blue series of dyes containing the 3,6-bis(dimethylamino)fluoren-9-yl moiety is reported. The consequent increased planarity of the system results in a large bathochromic shift of the x-band compared to the parent compound.     

The dyeing of poly(lactic acid) fibres with disperse dyes using ultrasound: Part 2 - Fastness

The use of ultrasound imparted greater colour strength to 1% omf dyeings of five of six disperse dyes studied, both before and after reduction clearing and had no effect on either the colour or λ_max of the dyeings. The lower fastness obtained to both wet and dry rubbing as well as to the first two/three of the five repeated wash cycles was attributed to the greater colour strength of the dyeings imparted by the use of ultrasound during dyeing.     

苯并吲哚二碳菁染料的合成及性质研究

为合成了2种新型的多甲川链上含氯取代的对称型苯并吲哚二碳菁染料,通过紫外-可见光谱、红外光谱、氢核磁共振谱和质谱对所得产物进行了表征。用紫外-可见光谱仪研究了溶剂、温度及光照时间对这2种染料吸收光谱的影响。结果表明,随着溶剂折射率n的增大,2种染料的最大吸收波长均有一定的红移;与阴离子为p-CH3C6H4SO3-的染料比较,阴离子为PF6-的染料具有较大的摩尔消光系数[λmax=676 nm,ε=2.45×105mol/(L.cm)]和良好的光、热稳定性。为合成稳定的、性能优良的光存储介质提供了实验基础。     

Synthesis and antimicrobial activity of certain novel monomethine cyanine dyes

A series of novel monomethine cyanine dyes were synthesized by using 3-methyl-5-substituted-1-phenyl-pyrano[2,3-c]pyrazole derivatives 2a–c. Reaction of equimolar ratios of 2a–c with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 3a–c. Reaction of compound 5 with 2(4)-methyl heterocyclic quaternary salts gives monomethine 6a–c. Condensation reaction of equimolar ratios of compounds 7 and 9a,b with 2(4)-methyl heterocyclic quaternary salts afforded the corresponding monomethine cyanines 8a–c and 10a,b respectively. The new synthesized monomethine cyanine dyes were identified by elemental analyses, IR, ¹H-NMR and Ms spectral data. The electronic absorption spectra in ethanolic solution of novel monomethine cyanine dyes were measured and the antimicrobial activity of some selected monomethine cyanine dyes was discussed.     

原子吸收分光光度法测定过磷酸钙中铬含量

用原子吸收分光光度法测定过磷酸钙中铬含量。实验研究适宜的分析条件,结果表明:试液中加入w(K2S2O7)10%的焦硫酸钾溶液10mL作为抑制剂,加入盐酸(1+1)2mL控制酸性介质的酸度,测定准确度较高,回收率为93.6%～101.1%。     

Decolorization of disperse and reactive dyes by continuous electrocoagulation process

The electrocoagulation process was developed to overcome the drawbacks of conventional wastewater treatment technologies. This process is very effective in removing organic pollutants including dyestuff wastewater and allows for the reduction of sludge generation. The purposes of this study were to investigate the effects of the operating parameters, such as current density, electrode number, electrolyte concentration, electrode gap, dyestuff concentration, pH of solution and inlet flow rate, on decolorization by continuous electrocoagulation. The dye removal efficiencies and reaction rate constants from the curves following the first-order relationship of electrocoagulation were calculated. In addition, from the points of power consumption, the effects of the operating parameters were also searched. Finally, the behaviors of decolorization according to dyestuff types, i.e., disperse dye and reactive dye, were also examined.     

原子吸收法测定循环醋酸中钴锰含量

介绍了原子吸收法测定PTA生产过程的循环醋酸中钴锰含量的方法 ,并把用该法测定的结果与X 射线荧光法测定结果进行比较 ,结果表明 ,前者精密度好 ,准确性高 ,速度快 ,杂质干扰小 ,完全可代替后者     

Studies of novel monomeric and polymeric azo disperse dyes

A series of polymeric dyes were synthesized by free‐radical addition polymerization of monomeric dyes that were derived from diazotized 2‐amino‐3,5‐bis‐(ethoxycarbonyl)‐4‐methylthiophene by coupling with various N‐arylmaleimides. All the polymeric dyes were characterized by elemental analysis, IR and visible spectroscopy, viscometry, and TGA. Color and dyeability of the polymeric dyes are discussed by comparing them with those of the corresponding monomeric dyes. All the dyes have been found to give various color shades with good to very good depth and levelness on the fiber. The dyeing of the monomeric dyes shows good fastness to light and very good to excellent fastness to washing, perspiration, sublimation, and solvents. The corresponding polymeric dyes show excellent fastness properties. The percentage dyebath exhaustion and fixation on the fiber have been found to be good to very good (60–90%). © 2002 Wiley Periodicals, Inc. J Appl Polym Sci 84: 1380–1389, 2002; DOI 10.1002/app.10276     

原子吸收分光光度法测铬浸取液中的钙含量

作为铬盐生产中间产品的浸取液，其钙含量的高低对后续生产工序有着重要影响，因而需要加以控制。若用容量法测定，因其中钙含量太低，不仅操作繁琐，时间长，且重现性差，而且误差较大。用原子吸收分光光度法测铬浸取液中的钙含量，方法简单、快速，在优化条件下，加标回收率为98．3％～103．3％，足以满足控制铬浸取液中钙含量的要求。对减少工艺过程中的结壁现象、降低消耗，起着重要作用。     

原子吸收分光光度法对东北黄芪中微量元素的全分析

本文以火焰原子吸收法和石墨炉原子吸收法测定了东北黄芪中14种微量元素的含量,并对4种预处理消化方法进行了比较,选择出对某种元素较好的测定方法。     

火焰原子吸收分光光度法测定某市化妆品中铅含量

长期使用含有重金属铅的化妆品,可能影响使用者自身及其后代的身体健康。铅中毒能够引起神经系统、代谢系统和内分泌系统等方面的疾病,严重影响着体内正常的新陈代谢。本文以某市市售化妆品为主要研究对象,采用火焰原子吸收分光光度法测定化妆品中的铅含量,结果显示5种化妆品的铅含量在2~6mg·kg-1以内,未超过国家标准所规定的40mg·kg-1。该方法可用于市售化妆品中铅含量的测定,测得回收率在90.50%~94.0%之间,准确度良好。     

Electronic properties of polymethine systems. 10. Electron structure and absorption spectra of cyanine bases

Complex quantum-chemical and spectral studies of the features of the electron structure and absorption spectra of the bases' derivatives of the symmetrical cyanine dyes are performed. It is found that moving from cationic cyanines to their neutral bases is accompanied by a drastic increase in the bond length alternation, equalizing the electron densities at atoms in the chromophore and by sharp shifting up of the molecular levels. Spectral bands in the absorption spectra of the bases are essentially wider and lower intensive and hypsochromically shifted, what is suggested to be connected with different nature of the first electron transition in the cyanine dyes and their bases.     

Density correlation of solubility of C. I. disperse orange 30 dye in supercritical carbon dioxide

The solubility of C. I. Disperse Orange 30 (O30) dye in CO₂ has been measured by using a closed-loop (batch) solid-fluid equilibrium apparatus at temperatures between 313 and 393 K and at pressures between 11 and 33 MPa. Kumar and Johnston’s equation based on Chrastil’s concept has been used to describe the experimental solubility data. The solubility versus density plot appears much simpler than the solubility versus pressure plot. The isotherms are nearly straight and parallel to each other, as seen in the previous studies. Peng-Robinson equation of state (PR EOS) has also been used successfully in modeling the dye solubility in supercritical carbon dioxide as a function of pressure or density of the fluid phase. The validity of this method has been verified by the vapor pressure calculation. This paper is dedicated to Professor Hyun-Ku Rhee on the occasion of his retirement from Seoul National University.