Pigments optical effect

Metallic, pearlescent and fluorescent pigments are grouped together in this section as three types of pigment used for their ability to produce unusual optical effects. 

Pfaff, G. Reynders, P. (1999) Angle dependent optical effects deriving from submicron structures of films and pigments. Chem. Reviews 99 1963-1981... 

Figure 5.17 Optical effects in plate-like layered pigments.

In systems where different pigments are combined (e.g., white and colored pigments), segregation effects can occur which change the optical appearance (flooding... 

On the other hand, new pigments based on transparent silica flakes show extremely strong optical effects, which are different to mica pigments [5.244]. Angle dependent colors and other effects, achieved by the combination of these Si02-flakes with... 

White pigments the optical effect is caused by nonselective light scattering (examples titanium dioxide and zinc sulfide pigments, lithopone, zinc white)... 

Effect pigments the optical effect is caused by regular reflection or interference... 

Interference pigments the optical effect of colored luster pigments is caused wholly or mainly by the phenomenon of interference (example iron oxide on mica)... 

The optical properties of rutile and anatase TIO2 are different in that anatase is more reflective than rutile at 380 nm and rutile Is very strongly UV-absorb-ent at 380 nm tFigure 2). (JL) The optical properties of the various pigments strongly effect photosensitizer absorption and photochemical activity. 

Most paint formulations consist of disperse systems (solid in liquid dispersions) [2]. The disperse phase consists of primary pigment particles (organic or inorganic) which provide the opacity, colour and other optical effects these are usually in the submicron range. Other coarse particles (mostly inorganic) are used in primers and undercoats to seal the substrate and enhance adhesion of the top coat The continuous phase consists of a solution of polymer or resin which provides the basis for a continuous film that seals the surface and protects it from the outside environment Most modem paints contain latexes which are used as film formers. These latexes - which typically have a glass transition temperature (Tg) below... 

Some of the metallic inorganic pigments are used for their non-optical effects. They can provide a complete optical barrier against visible, infrared (IR) and UV radiation. 

The advantages of wood fillers include low density, low equipment abrasiveness, relatively low cost, and good biodegradability. Moreover, plastics provide good moisture and decay resistance [56]. In addition, various surface optical effects can be obtained by adding different wood species and coloured pigments [57]. 

There is an interesting and diverse range of pigment types which have the ability to produce novel and unusual optical effects in application. These products, which include metallic, pearlescent,... 

Sasamoto Y, Gomi F, Sawa M, Tsujikawa M, Nishida K (2011) Effect of 1-year lutein supplementation on macular pigment optical density and visual function. Graefes Arch Clin Exp Ophthalmol 249 1847-1854. doi 10.1007/s00417-011-1780-z... 

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