Solvent- and Light-Sensitive AIEE-Active Azo Dye: From Spherical to 1D and 2D Assemblies

Fluorescent molecular assembly systems provide an exciting platform for creating stimuli-responsive nano- and microstructured materials with optical, electronic, and sensing functions. To understand the relationship between (i) the plausible molecular structures preferentially adopted depending on the solvent polarity (such as N,N-dimethylformamide [DMF], tetrahydrofuran [THF], and toluene), (ii) the resulting spectroscopic features, and (iii) self-assembled nano-, micro-, and macrostructures, we chose a sterically crowded triangular azo dye (3Bu) composed of a polar molecular core and three peripheral biphenyl wings. The chromophore changed the solution color from yellow to pink-red depending on the solvent polarity. In a yellow DMF solution, a considerable amount of the twisted azo form could be kept stable with the help of favorable intermolecular interactions with the solvent molecules. By varying the concentration of the DMF solution, the morphology of self-assembled structures was transformed from nanoparticles to micrometer-sized one-dimensional (1D) structures such as sticks and fibers. In a pink-red toluene solution, the periphery of the central ring became more planar. The resulting significant amount of the keto-hydrazone tautomer grew into micro- and millimeter-sized 1D structures. Interestingly, when THF-H₂O (1:1) mixtures were stored at a low temperature, elongated fibers were stacked sideways and eventually developed into anisotropic two-dimensional (2D) sheets. Notably, subsequent exposure of visible-light-irradiated sphere samples to solvent vapor resulted in reversible fluorescence off↔on switching accompanied by morphological restoration. These findings suggest that rational selection of organic dyes, solvents, and light is important for developing reusable fluorescent materials.     

生物电化学法强化A/O工艺处理印染废水

印染废水处理常用的A/O工艺,存在脱色效果差,容积负荷较低等缺点.采用酸性橙7模拟印染废水的主要成分,试验生物电化学法对传统A/O工艺处理印染废水的强化作用.结果表明:在A/O工艺中引入生物电化学系统后,酸性橙7的容积负荷可达17.7 g/(m3·d),比A/O工艺提高了55.4％,具有较明显的强化作用.     

介质阻挡放电等离子体对茜素红溶液的降解

利用介质阻挡放电等离子体法对染料茜素红溶液进行降解。考察了放电间距、输入电压及溶液pH值对茜素红降解效果的影响,并通过测定放电过程溶液中活性粒子O₃的浓度,探讨了促使茜素红降解的主要因素。结果表明,高压电极与液面间距为8 mm、输入电压为8 kV时,降解效果较好。其中弱碱性环境下（pH=8.4）降解效果最好,40 min后茜素红浓度降为0.26 mg·L^-1,在弱酸性环境（pH=5.8）中处理45 min后,茜素红浓度为1.61 mg·L^-1,而在中性环境（pH=7.0）中降解效果较差,处理45 min后茜素红残留浓度为5.70 mg·L^-1。溶液中的O₃是推动氧化反应进行的主要因素。     

两种荧光染料的光稳定性研究

采用标准氙灯分别光照自制的苯乙烯吡啶盐阳离子荧光橘红DHEASPBr-C2和市售的阳离子荧光黄X-10GFF染色腈纶织物,探究两种染料光稳定性。在染料0.05%（omf）条件下,阳离子荧光黄X-10GFF染色腈纶织物的荧光强度大于阳离子荧光橘红DHEASPBr-C2;在标准氙灯光照条件下,两只染料均发生不同程度的光褪色,前者略好于后者。采用量子化学中的密度泛函方法(DFT),揭示两种染料光降解机理。阳离子荧光橘红DHEASPBr-C2因具有较多的活泼位点,更易在空气中发生光褪色。     

羧化硬脂醇聚氧乙烯醚马来酸双酯在皂洗中的应用

合成了一种新型的阴离子 非离子双子表面活性剂羧化硬脂醇聚氧乙烯醚马来酸双酯（POE 5）,并将其应用于活性染料染色棉织物的皂洗。从K/S值、L*值、耐洗色牢度及摩擦牢度等指标探讨了皂洗温度和POE 5用量对皂洗效果的影响。结果表明：优化的皂洗工艺为皂洗温度60～80 ℃,POE 5 0.5 g/L,皂洗后染色织物的K/S值和各项牢度可达到或超过标准皂洗（皂片2 g/L,温度100 ℃）的效果。     

丁香色素对棉织物染色和抗紫外性能探讨

用水提取天然染料丁香,提取时间90 min为宜,存放一周可以正常使用。用亚铁后媒染染色的棉织物表观得色量最大,牢度达3级以上,颜色为灰黑色,适合仿古风格。优化的染色工艺配方为：亚铁后媒染,媒染剂5%（owf）、温度80 ℃、时间50 min。经媒染的染色棉织物的抗紫外性能有所提升。     

减轻纸张色差的生产实践

针对色纸生产过程中经常出现较大色差的情况，本文介绍了减轻色差采取的一些措施。     

Novel Ag-AgBr decorated composite membrane for dye rejection and photodegradation under visible light

Photocatalytic membranes have received increasing attention due to their excellent separation and photodegradation of organic contaminants in wastewater. Herein, we bound Ag-AgBr nanoparticles onto a synthesized polyacrylonitrile-ethanolamine (PAN-ETA) membrane with the aid of a chitosan (CS)-TiO₂ layer via vacuum filtration and in-situ partial reduction. The introduction of the CS-TiO₂ layer improved surface hydrophilicity and provided attachment sites for the Ag-AgBr nanoparticles. The PAN-ETA/CS-TiO₂/Ag-AgBr photocatalytic membranes showed a relatively high water permeation flux (~ 47 L·m^–2·h^–1·bar^–1) and dyes rejection (methyl orange: 88.22%; congo red: 95%; methyl blue: 97.41%; rose bengal: 99.98%). Additionally, the composite membranes exhibited potential long-term stability for dye/salt separation (dye rejection: ~97%; salt rejection: ~6.5%). Moreover, the methylene blue and rhodamine B solutions (20 mL, 10 mg·L⁻¹) were degraded approximately 90.75% and 96.81% in batch mode via the synthesized photocatalytic membranes under visible light irradiation for 30 min. This study provides a feasible method for the combination of polymeric membranes and inorganic catalytic materials.     

直接染料上染聚氨酯弹性纤维的染色动力学和热力学分析

为更好地控制染料的应用性能和在染色中的性能,研究了直接染料上染聚氨酯弹性纤维及其长丝的染色性能。被染样品通过傅里叶变换红外光谱加以分析,获得的动力学和热力学研究结果与傅里叶变换红外分析结果一致。     

磨绒织物活性印花抗沾色皂洗工艺

通过使用新型的助洗剂MD，有效地降低了磨绒织物活性染料印花后的皂洗沾色，减少了洗水次数，获得了满意的洗水效果。试验发现，其最佳用量为4g／L。