Cover Picture: Macromol. Mater. Eng. 2/2004

Opaline effect pigments by spray induced self‐assembly on porous substrates

Self‐assembling of opaline materials on porous substrates like paper requires a very fast crystallization, which can be realized with highly monodisperse colloids. This opens the possibility of applying effect pigments to such substrates not by spraying the rather large effect pigments themselves, but by spraying their building blocks, which self‐assemble later on. The feasibility of this approach is presented here for monodisperse polymethyl methacrylate (PMMA) spheres. This process tolerates additives used for ink‐jet printing.

Artificial Opals as Effect Pigments in Clear-Coatings

In this paper, we describe the use of artificial opals from polymer beads as effect pigments in transparent industial and automotive coatings. For this purpose, we synthesized monodisperse colloids from fluorinated methacrylates by surfactant-free emulsion polymerization. The fluorinated monomers, in combination with crosslinking, lead to a refractive index contrast, thermal stability, and solvent resistivity necessary for use as effect pigments. After crystallization of the monodisperse polymer beads, crystal flakes with iridescent colors can be obtained. The crystal flakes can act as effect pigments in various transpartent industrial and automotive coatings. due to photonic crystal behavi…