Palladium-catalysed amination of bromofluorans and an investigation of their thermochromic behaviour

The palladium-catalysed amination of readily accessible bromofluorans and bromobenzo[a]fluorans has been accomplished with a series of anilines and morpholine. The resulting aminofluorans generated intense black shades upon formulation in methyl stearate containing bisphenol A. The route provides an alternative approach to various amino substituted fluorans without the need of a series of individual diphenylamine intermediates.     

Diphenylamino-substituted derivatives of 9-phenylcarbazole as glass-forming hole-transporting materials for solid state dye sensitized solar cells

The synthesis and properties of glass-forming diphenylamino-substituted derivatives of 9-phenylcarbazole with methoxy groups in the different position of diphenylamino moieties are reported. A comparative study on their thermal, optical, photoelectrical and electrochemical properties is presented. The synthesized compounds exhibit high thermal stability with 5% weight loss temperatures ranging from 344 to 475 °C. The derivatives absorb electromagnetic irradiation in the range of 225–425 nm with the band gaps of 2.94–3.08 eV. The ionization energies of the synthesized compounds range from 5.04 to 5.56 eV. The lowest ionization energies and band gaps are observed for compounds containing para methoxy-substituted phenyl rings of diphenylamino moieties and for disubstituted carbazole derivatives. Charge-transporting properties of the selected compounds were tested by time-of-flight technique. Hole drift mobilities in the amorphous layers of the materials reach 10⁻³ cm²/V s at high electric fields. The derivatives were tested as hole transport materials in solid-state dye sensitized solar cells and showed conversion efficiency up to 0.54%.     

A green approach to the fabrication of titania–graphene nanocomposites: Insights relevant to efficient photodegradation of Acid Orange 7 dye under solar irradiation

Environment friendly and efficient strategy for the preparation of titanium dioxide (TiO₂)–graphene (GR) based hybrid nanocomposite has been demonstrated by simple chemical approach for the photodegradation of Acid Orange 7 (AO7) dye under solar irradiation. The resultant nanocomposite structure and composition has been characterized by Ultraviolet Diffusive Reflectance Spectroscopy (UV-DRS), Fourier Transform Infrared Spectroscopy (FTIR), Thermogravimetric Analysis (TGA), Raman spectroscopy and X-ray diffraction (XRD) studies. The incorporation of TiO₂ nanoparticles on the surface of GR was confirmed by High Resolution Transmission Electron Microscopy (HRTEM) and Field Emission Scanning Electron Microscopy (FESEM) studies. Electrochemical Impedance spectroscopy (EIS) and Cyclicvoltammetry (CV) studies revealed that the incorporation of GR with TiO₂ nanoparticles significantly enhanced the redox property and electrical conductivity. During photocatalysis, the TiO₂–GR nanocomposites have high photocatalytic activity compared with that of TiO₂ towards AO7 dye degradation under solar light irradiation. The enhanced photocatalytic activity might be attributed to the role GR played as an electron acceptor and transporter in the composite film, which effectively suppressed the charge recombination and promoted the charge transfer within the composite.     

Integrated LaB6/g-C3N4 solar absorber for solving dye accumulation during solar steam generation

Solar steam generation has attracted considerable interest due to its easy accessibility and sustainability. However, dye molecules were gradually concentrated on bulk water or the surface of solar absorbers during the disposal of dye wastewater. Herein, LaB₆/g-C₃N₄ composites were immobilized on porous cotton cloth, served as a solar absorber resistant to dye clogging. The optimal solar absorber possessed solar harvesting of 92.3% and showed great application potential in the field of the treatment of dye wastewater. This study presented a new approach for the treatment of dye wastewater.     

Metallurgical slag properties as a support material for bimetallic nanoparticles and their use in the removal of malachite green dye

Fe-Cu oxides nanoparticles (Nps) were embedded in two steel slag wastes (SSB and SSW) to develop SSB/Fe-Cu and SSW/Fe-Cu nanocomposites. Nps with mean sizes between 10–20 and 6–10 nm on SSW and SSB, respectively are agglomeration with a different shape. Their characteristics were investigated by XRD, TEM, BET, SEM techniques. The Nps modified the morphology of both support materials. XRD pointed out the presence of Cu and Fe. The proportion of Cu concentration was higher than the one of Fe. Nanocomposites were tested in malachite green removal from aqueous solution. The adsorption kinetic indicated physisorption and chemisorption as the main mechanisms of adsorption. The adsorption capacities were 88.26 and 63.55 mg/g for SSW/Fe-Cu and SSB/Fe-Cu, respectively. This novel, easy to prepare and low-cost nanocomposites is an efficient adsorbent material. The presence of calcium compounds may improve Nps deposition an MG removal. Materials with ferric phases are not as efficient as the first one; Fe is not well supported on the material. The removal of MG took place by dye structure modification and by interactions with Cu nanoparticles improving the oxidation-reduction process, through synergic effects.     

羊绒织物前处理工艺研究

羊绒织物因其优异的服用性能,越来越受欢迎。但是,现有的羊绒织物前处理工艺与高温沸染工艺分别存在着污染问题和高能耗问题,不符合当今绿色发展的主题。所以,为了解决该问题,实验采用生化试剂610替代二氯异氰脲酸。实验通过对比610与DCCA各浓度下处理的羊绒纱线的力学性能、染色性能,并创新的从染色动力学方面对其进行深入探讨,选出较优的610浓度。最终,确定选择1%(owf)的610代替DCCA并且与0.5%(owf)的碱性蛋白酶复合处理羊绒纱线。其实验结果为:强力损失率为7.51%,羊绒鳞片层基本结构保留,固色率为95.77%,上染速率常数为0.05,t1/2为13.87min。     

Cathode modification with peptide nanotubes (PNTs) incorporating redox mediators for azo dyes decolorization enhancement in microbial fuel cells

To enhance azo dye reduction in cathode of microbial fuel cells (MFCs) and power generation, a novel cathode modification method was developed on carbon paper (CP) through immobilization of redox mediators (RMs) with self-assembled peptide nanotubes (PNTs) as the carrier. Results showed that the optimum peptide concentration for PNT self-assembly on electrode and Orange II decolorization in MFCs was 2 mg mL^?1. The PNT/RMs/CP electrodes exhibited higher electrocatalytic activities than PNT or RM solely modified electrodes and raw carbon paper electrode. MFCs loaded with the riboflavin (RF)/PNT modified cathode (PNT/RF/CP) or anthraquinone-2, 6-disulfonate (AQDS)/PNT modified cathode (PNT/AQDS/CP) showed an enhanced decolorization rate to Orange II compared to that with the control electrode, with the reduction kinetic constants increased by 1.3 and 1.2 folds, respectively. Furthermore, the MFCs with the PNT/AQDS/CP cathode and PNT/RF/CP cathode generated a higher maximum power density of 55.5 mW m^?2 and 72.6 mW m^?2, respectively, compared to the control (15.5 mW m^?2). The PNT/RMs modification could reduce cathode total internal resistance and accelerate electron transfer from electrodes to dyes, which may result in the enhanced performance of MFCs.     

The stability of monochlorotriazinyl reactive dyes on cellulose films in aqueous alkaline solutions containing peroxide bleaching agents

The stability of seven reactive (one difluoromonochloropyrimidinyl and six monochlorotriazinyl) dyes on cellulose immersed in sodium peroxoborate (PB) solution (UK–TO solution) containing tetraacetylethylenediamine (TAED) was examined using cellulosic films at 60 °C. The extent of dye loss that occurred from the dyed cellulosic films which were immersed in the UK–TO solution without detergent correlated closely to the ratings obtained using the BS 1006 UK–TO wash test. The dye loss that occurred from the dyed cellophane films was attributed to three contributions, namely, alkaline hydrolysis of dye–fibre bonds, oxidative fading of the dye chromophore by peroxides and cellulose degradation accelerated by PB and TAED. The alkaline hydrolysis of the dye–fibre bond and the extent of cellulose degradation in the UK–TO solution were the main contributions to the dye loss; dye oxidation was a minor factor in the dye loss mechanism. The physical bonding of the dye molecules reinforced the covalent dye–fibre bond stability towards the UK–TO solution.     

分散染料的近期进展

介绍了分散料的近期进展，包括原有涂纶织物着色用散染料，超细旦纤维用分散染料，以及分散染料在喷射打印墨水和热转称铖像上的应用，展望了分散染料今后的发展方向。