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Atomic, Molecular, and Optical Physics
Published in W. M. Haynes, David R. Lide, Thomas J. Bruno, CRC Handbook of Chemistry and Physics, 2016
W. M. Haynes, David R. Lide, Thomas J. Bruno
Type (characteristic) Gas Atom, neutral (electronic transition) Atom, ionic (electronic transition) Molecule, neutral (electronic transition) Molecule, neutral (vibrational transition) Molecule, neutral (rotational transition) Molecule, ionic (electronic transition) Liquid Organic solvent (dye-chromophore) Organic solvent (rare earth chelate) Inorganic solvent (trivalent rare earth ion) Solid Insulator, crystal (impurity) Insulator, crystal (stoichiometric) Insulator, crystal (color center) Insulator, amorphous (impurity) Semiconductor (p-n junction) Semiconductor (electron-hole plasma) Representative example Neon-Helium (Ne-He) Argon (Ar+) Krypton uoride (KrF) Carbon dioxide (CO2) Methyl uoride (CH3F) Nitrogen ion (N2+) Rhodamine dye (Rh6G) Europium:TTF Neodymium:POCl4 Neodymium:YAG Neodymium:UP(NdP5O14) F2-:LiF Neodymium:glass GaAs GaAs Nominal operating wavelength (nm) 633 488 248 10600 496000 420 580-610 612 1060 1064 1052 1120 1061 820 890 Method(s) of excitation Glow discharge Arc discharge Glow discharge; e-beam Glow discharge; gasdynamic ow Laser pumping E-beam Flashlamp; laser pumping Flashlamp Flashlamp Flashlamp, arc lamp Flashlamp Laser pumping Flashlamp Injection current E- beam, laser pumping
Restricted substances for textiles
Published in Textile Progress, 2022
Arun Kumar Patra, Siva Rama Kumar Pariti
Many of the application classes of textile dyes have the azo group as their chromophore. In some cases, the same colourant may be classified into more than one application class. For example, disperse dyes can often be applied as solvent dyes and vat dyes sometimes applied as pigments. Like disperse colours, solvent dyes are also non-ionic and sparingly soluble in water, but the molecular weight of solvent dyes is higher. Typically, solvent dyes are used for the colouration of inks, plastics, waxes, fat products and mineral oil products (Ollgaard, Frost, Galster, & Hansen, 1998). Azo pigments are similar to disperse dyes, solvent dyes and mordant dyes in terms of possessing very low solubility in water, their molecular size and hydrophobicity. However, the main differentiator for pigments is their low solubility in organic solvents as well as in water. In another instance, acid dyes and direct dyes are both anionic, water-soluble dyes with similar organic structure but acid dyes usually have lower molecular weight. The following table gives a classification of azo dyes (Table 6).