In this PhD thesis, a new process for the production of polymeric specimens with a colloidal crystalline structure is described, from the synthesis up to the processing techniques. Monodispersed latex particles (diameter = 200 - 400 nm) with a core of polystyrene and a shell of polyethylacrylate were prepared by stepwise emulsionpolymerisation. The polyethylacrylate shell is fairly completely grafted to the strongly crosslinked polysterene core by means of a polymeric interlayer. When the mass of these core-shell latex spheres is compressed to latex films, by uniaxial compression at elevated temperatures, the polystyrene cores arrange themselves in the matrix of the polyethylacrylate shells in the fashion of a colloidal crystalline lattice with face centered cubic (fcc) order. The process is driven by a new mechanism of self-assembly. The fcc structure corresponds to that of natural opals, which are beautifully colored gemstones. The quality of the fcc lattice was characterised by transmission electron microscopy which revealed that the hexagonal closed packed (111) plane is always oriented parallel to the film surface. The ordered films exhibit angle dependent reflection colors, due to Bragg scattering of visible light, and, in transmission, the complementary colors. The colors depend on the size of the latex spheres while the intensity depends on the optical contrast between the cores and the shells. These latex films display rubber elasticity and can be deformed reversibly whereby the crystalline lattice is deformed, too, which alters the reflection colors. Scattering at the (220) plane of the lattice which runs at an olique angle through the film leads to a starlike reflection with a six-armed radial symmetry. This phenomenon demonstrates that the fcc lattice is macroscopically orientated in the films. These films consist, in fact, of single crystals. The only element of diorder on the macroscopic scale is twinning: the crystal orientation changes sometimes into its mirror image. This extraordinary orientation of the lattice is induced by the shear forces in the melt during film formation. The latex films can be laminated with commercial thermoplastics like polycarbonate which leads, by thermoforming, to effect-color materials of arbitrary shapes. From core-shell particles with a particularly thin shell of polyethylacrylate, colloidal crystals were prepared by drying techniques that were developed by other groups. The adavnatage of the thin shells is that they merge where the spheres touch, in the lattice, without filling the whole space between the spheres. The remaining pores can be filled with titanium dioxide. When, afterwards, the polymer spheres are removed, a fcc lattice of interconnected pores results that is known as the inverse opal structure. This nanoporous cocontinuous structure, which is distinguished by a high refractive index contrast, open the route towards photonic crystals with a complete band-gap. | English |