Azo dyes are one of the oldest industrially synthesized organic compounds characterized by presence of Azo bond (-N=N-) and are widely utilized as coloring agents in textile, leather, cosmetic, paint, plastic, paper, and food industries During textile processing, inefficiencies in dyeing result in large amounts of the dyestuff (varying from 2% loss when using basic dyes to a 50% loss when certa...

A simple and easy solubility enhancement of basic dyes was performed with bulky and symmetric weakly coordinating anions (WCAs). The WCAs decreased the ionic character of the dyes by broadening the partial charge distribution and causing a screening effect on the ionic bonding. This new modification with WCAs has advantages in that it has no influence on the optical properties of the dyes. The ...

Dyes derived from natural materials such as plant leaves, roots, bark, insect secretions, and minerals were the only dyes available to mankind for the coloring of textiles until the discovery of the first synthetic dye in 1856. Rapid research strides in synthetic chemistry supported by the industrialization of textile production not only led to the development of synthetic alternatives to popul...

Dyes are synthetic organic compounds widely used in various industries such as, textile, leather, plastic, food, pharmaceutical, and paints manufacturing industries. Coloured effluents are highly toxic to the aquatic life and mutagenic to humans. Wastewater containing dyes has become an important issue demanding serious attention. Among the synthetic dyes, azo dyes are the largest and most wide...

Heptamethine cyanine dyes are attractive compounds for imaging purposes in biomedical applications because of their chemical and photophysical properties exhibited in the nearinfrared region. A series of meso amino-substituted heptamethine cyanine dyes with indolenine, benz[e]indolenine and benz[c,d]indolenine heterocyclic moieties were synthesized and their spectral properties including fluore...

This review article highlights progress in understanding the optical properties of paper. Paper’s appearance can be defined in terms of its opacity, brightness, color, fluorescent properties, gloss, and various quantities related to its uniformity. The phenomena that give rise to paper’s optical properties, especially its ability to scatter and absorb visible light, are highly dependent on pape...

A new preparation method of polymer dyes was developed to improve both the grafting degree of the azo dyes onto O-carboxymethyl chitosan (OMCS) and the water solubility of prepared polymer dyes. Firstly, the coupling compound of two azo edible colorants, sunset yellow (SY) and allura red (AR), was grafted onto OMCS, and then coupled with their diazonium salt. The chemical structure of prepared ...

This thesis examines the capability of current techniques in fiber classification such as UV-visible microspectrophotometry (MSP) (for dye in situ and/or extracted) to discriminate between fibers from sources known to be different. When these methods fail to adequately distinguish the fibers, novel alternative techniques, such as pulsed pumped laser-induced fluorescence spectroscopy (LIF) and l...

A spectroscopic probe with multiple detecting fibers was used for quantifying absorption and scattering in liquid optical phantoms. The phantoms were mixtures of Intralipid and red and blue food dyes. Intensity calibration for the detecting fibers was undertaken using either a microsphere suspension (absolute calibration) or a uniform detector illumination (relative calibration between detector...

As part of a continuing research program aimed at plausible approaches to synthetic dyes based on toxicological considerations, a group of premetallized iron complexed monoazo dyes were synthesized as potential alternatives to presently used high volume Crand Cocontaining monoazo acid dyes for nylon and wool. This approach takes advantage of the environmentally friendly property of Fe, and draw...