Photoalignment dynamics of azo dyes series with different coordination metals

There are many photoaligned azo dyes that can be used for orientation of liquid crystals in various display devices. However, the structure of these compounds needs to be optimized to increase the rate of the process of molecule photoalignment, as well as to spread the application of these compounds. The main coordination metal that presents in the molecules of azo dyes is sodium derivatives. The use of other alkali metals remains an open question. We used quantum‐chemical computation methods and reversible intermolecular bonding model to determine the effect of metal coordination on the velocity of photoalignment. The theoretical predictions were experimentally verified using sodium, potassium, lithium, and cesium salts of the model azo dye synthesized by us. We conclude that potassium azo derivatives are the fastest, ceteris paribus.     

Photocatalytic decoloration of water-soluble azo dyes by reduction based on bisulfite-mediated borohydride

Investigation of the photocatalytic decoloration of nine water-soluble anionic azo dyes widely used for the coloration of textiles was conducted in a photoreactor by a selected reduction based on bisulfite-mediated borohydride. The influence of the irradiation power on their decoloration was discussed in this work. The decoloration processes of two typical azo dyes, Reactive Red MS and C.I. Direct Blue 15 were examined with UV–vis measurement and their decoloration kinetics was also investigated. Moreover, identification of benzidine compounds released from the photoreduction of four direct dyestuffs was undertaken. The results indicated that the reduction of the dyes was significantly enhanced under the increasing irradiation. It was found that the overall degradation followed pseudo-first-order kinetics and two distinct stages were observed in the decoloration processes of Reactive Red MS and C.I. Direct Blue 15. The decay rates at first stage were slightly changed, but the decay rates at second stage were significantly affected by the light intensity. In addition, UV–vis spectra showed that the azo linkages in molecule structure of the dyes were destroyed during the decoloration. Finally, dimethoxyl benzidine or benzidine produced from the photoreduction of four direct dyes was identified as the decoloration products through a rapid spectrophotometric method.     

2，4－二硝基－6－氰苯胺的合成研究

以水杨酸为原料，经硝化、酰卤化、氨化等三步反应，得到重要的染料中间体２，４－二硝基－６－氰苯胺，总收率７０．５％。     

Synthesis and properties of an alkoxysilane dye containing three electronic donor groups for nonlinear optical applications

In order to obtain an efficient hybrid inorganic–organic nonlinear optical (NLO) materials, an azo-dye containing three electronic donor groups 2,5-dimethyl-4-(4′-nitrophenylazo)phenol (DMNPAP) was synthesized and reacted with 3-isocyanatopropyl triethoxysilane (ICTES) to give an alkoxysilane dye (ICTES–DMNPAP). Molecular structural characterizations for DMNPAP and ICTES–DMNPAP were investigated by elemental analysis, ¹H NMR, FTIR, UV–visible spectra and differential scanning calorimetry (DSC). The alkoxysilane dye could be hydrolyzed and polymerized in the presence of water, and then transparent hybrid films could be fabricated by spin coating on the indium–tin-oxide (ITO) glass substrates. Compared with the dye 4-nitro-4′-hydroxy-azobenzene (NHA) containing only one hydroxyl as donor group, DMNPAP exhibited larger β_CTμ_g value measured by solvatochromic method, and second harmonic generation (SHG) measurement of the hybrid films was in agreement with the result.     

用木质素磺酸铵作标准化试剂提高单偶氮、双偶氮酸性染料的冷水溶解度的方法

一般的酸性染料溶解度较小,而本文所介绍的单或双偶氮酸性染料,实际上是以碱金属盐的形式存在,由于加入了（按重量计）80％～30％的木质素磺酸铵,改善了室温的冷水溶解度。木质素磺酸铵既作为标准化试剂,用来调节高强度染料到稳定的商品染料,同时又能提高染料在室温时冷水溶解度。     

分散染料在涤/锦双组分纤维上色差的色度学分析

将涤 /锦复合丝分离成单一组分的超细涤纶和锦纶。用常用的分散染料同浴染色后 ,测定了各染色样品的颜色三刺激值 ,并经过色度学计算。实验分析表明 ,分散染料对锦纶染色物的反射光主波长值较相应涤纶染色物向长波方向移动 ;蒽醌类分散染料在锦纶上的得色量较小 ,彩度较低 ;而偶氮类分散染料对涤 /锦染色的总色差较小 ,较适合于涤 /锦复合丝的染色。     

铁碳微电解及Fenton氧化法在染料废水处理中的应用

探讨了铁碳微电解及Fenton氧化法的反应机理、影响因素,总结了微电解和Fenton氧化法的优缺点,概述了微电解与Fenton氧化法联用在废水处理中的应用及其发展前景。     

界面光催化剂对罗丹明B的吸附及其光催化性能研究

以中空粒子TiO2@@SiO2为载体,通过表面烷基化改性,制备出一种能漂浮于水面的界面光催化剂TiO2@@SiO2-O,并用IR,TG,接触角对其进行表征。结果表明:在无搅拌状态下,与中空粒子TiO2@@SiO2相比,界面光催化剂TiO2@@SiO2-O对罗丹明B的吸附性大大增加,其光催化效率提高了30%。     

紫草在柞丝绸织物染色中的应用

对紫草用于柞蚕丝织物的染色性能进行了探讨。用乙醇提取紫草色素,选取染液体积分数、pH值、温度和时间4个因素,通过正交试验及单因素分析试验,优化出紫草上染柞蚕丝织物的最佳工艺条件为:浴比1∶40,染液体积分数8%,pH 6,温度80℃,时间60 min。通过不同媒染剂(Al3+、Fe2+、Cu2+)媒染处理,得到不同颜色的织物。通过对染色织物耐水洗及耐摩擦色牢度的检测得出,紫草上染柞蚕丝织物色牢度优良,直接染色和媒染均达到3级以上。     

非均相催化湿式氧化活性红2BF的研究

以Fe/AC为催化剂、O2为氧化剂的非均相催化氧化体系处理偶氮染料活性红2BF,考察了反应温度、氧分压、废水pH、催化剂投加量等因素对降解效果的影响。结果表明,染料初始质量浓度为400 mg/L时,在温度150℃、氧分压0.5 MPa、pH=3、反应时间60 min、催化剂投加量为4 g/L的最佳条件下,活性红2BF色度几乎完全去除,TOC去除率达94.21%。