Difference between revisions of "Color emulation"
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Revision as of 10:21, 18 January 2015
There are several ways to make a material have color.
Contents
Local origins of color
The electons in molecules are layered over one another since they are fermions and thus obey paulis exclusion principle. Light can only be absorbed when at least the energy to the next higher allowed energy level is reached (and some further restrictions are obeyed). In simple molecules like dinitrogen (air) very high photo energies are needed to excite an electron (hard UV?). The problem is that the excited electron was responsible for the bond between the two atoms so the molecule falls apart.
Creating chains of double-bonded carbon atoms creates a big shared space for the participating electrons. Since they now have more spacial freedom according to heisenbergs uncertainty principle their impulse can be smaller. This has the nice effect that you gain some energy levels that are higher than the unexcited "sea level" of molecule orbital electrons[1] but are still low enough such that the electrons still fulfill their responsibility of holding the molecule together. (the molecules shape may change though sometimes)
[note 1] also known as HOMO - for highest occupied molecular orbital) meaning that
bring the relative height of electron energy levels in the range of energy of visible light.
long chains low wavelengths (red end of the spectrum)
Chain like molecules may be hard to mechanosythesize (or not).
- Pigments: [1]
- Color centers: [3]
Bigger scale origins of color
interference patterns
like the ones butterflies use or simpler ones like ...
plasmonic surface effects
[Todo: check inhowfar quantum dots are related]
