pigments_lect1(1)

pigments_lect1(1) - 1 Pigments Pigments Pigment: Coloring...

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Unformatted text preview: 1 Pigments Pigments Pigment: Coloring matter used to make paint. Pigments work by selectively absorbing a portion of the visible light while the remaining visible light is reflected. For more info see http://webexhibits.org/pigments/ The Visible Spectrum The Visible Spectrum UV 100-400 nm 12.4 - 3.10 eV Violet 400-425 nm 3.10 - 2.92 eV Blue 425-492 nm 2.92 - 2.52 eV Green 492-575 nm 2.52 - 2.15 eV Yellow 575-585 nm 2.15 - 2.12 eV Orange 585-647 nm 2.12 - 1.92 eV Red 647-700 nm 1.92 - 1.77 eV Near IR 10,000-700 nm 1.77 - 0.12 eV If absorbance occurs in one region of the color wheel the material appears with the opposite ( complimentary color ). For example: a material absorbs violet light Color = Yellow a material absorbs green light Color = Red a material absorbs red, orange & yellow Color = Blue E = hc/ = {(6.626 x 10-34 J-s)(2.998 x 10 8 m/s)}/ 1 eV = 1.602 10-19 J 2 Absorption spectrum for Absorption spectrum for [Ti(H [Ti(H 2 O) O) 6 ] 3+ 3+ UV UV-Visible Absorption Spectroscopy Visible Absorption Spectroscopy Absorbs: Absorbs: Blue, Green Blue, Green Partially Absorbs: Partially Absorbs: Violet, Yellow Violet, Yellow Transmits: Transmits:...
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pigments_lect1(1) - 1 Pigments Pigments Pigment: Coloring...

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