Recent Developments in the Colour and Constitution of Organic Dyes

The use of the Cytogenetic to Identify Mechanisms of Action of an Azo Dye in Allium Cepa Meristematic Cells

“…The slides were mounted in synthetic [44]. The slides were observed and analyzed by fluorescence photomicroscopy (450-490 nm filters for CMA 3 , and 320-380 nm for DAPI), at least 15 days following their preparation. All the assays performed with fluorescent staining were developed in a dark room.…”

“…Moreover, they enable a wide variety of colors to be obtained in contrast to natural dyes [3]. However, during the textile process, staining inefficiency results in a large quantity of residues, all of which are directly discharged into bodies of water, consequently contaminating the environment [4][5], creating serious environmental impacts [6].…”

Dyeing with Disperse Dyes

“…Recent literature has revealed that more bathochromic shifts can be obtained by condensing various arylamines with 4-arylamino-5-nitro-1,8-dihydroxy anthraquinone or with 4,8-dichloroquinizarin or 4,5-dinitrochrysazin to give deep blush-green shades on polyester (Peters & Chao; Yu & Chao]. Although anthraquinone disperse dyes have many advantages such as bright shades, high light fastness, good stability in dyeing and excellent levelling, serious economic drawbacks and inevitable pollution problems ensure the continuing displacement of these dye by other types, such as benzodifuranone dyes and azo dyes having heterocyclic diazo components (Griffiths, 1984;Weaver & Shuttleworth, 1982 Some general trends can be distinguished but, within these, more subtle interactions involving electronic and steric effects make it very difficult to set down hard and fast rules. In recent years, more precise information has been obtained by studying groups of very closely related dyes in which minor structural changes have been shown to influence fastness properties.…”

Synthesis and Application of Some Alkali‐Clearable Azo Disperse Dyes Based on Naphthalimide Derivatives

“…Finally, there is the unavoidable fact that there is a natural limit to the number of dyes needed by the textile industry, and the current status of dye development is such that further improvements in performance and economics of existing dyes are likely to be minimal. 1 These limitations, which have been performed by the world organizations for decreasing pollution of environment, have caused increasing requirements for manufacturing environmentally friendly dyes. Disperse dyes are slightly soluble in water, and they can be applied as a dispersion in water on polyester fibers.…”

“…Firstly, the massive increase in oil prices and subsequent recession of recent years has hit the dye and textile industries particularly severely. 1 Secondly, the introduction of stringent toxicological test requirements for new products and severe regulations for protecting environment, have made the introduction of new dyes a much less attractive proposition. Finally, there is the unavoidable fact that there is a natural limit to the number of dyes needed by the textile industry, and the current status of dye development is such that further improvements in performance and economics of existing dyes are likely to be minimal.…”