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The spontaneous formation of dendritic aggregates is observed in a two-dimensional confined layered system consisting of a film composed of liquid crystal, dye and solvent cast above a polymer substrate. The observed aggregates are promoted by phase separation processes induced by dye diffusion and solvent evaporation. The growth properties of the aggregates are studied through the temporal evolution of their topological properties (surface, perimeter, fractal dimension). The fractal dimension of the completely formed structures, when they are coexistent with different types of structures, is consistent with theoretical and experimental values obtained for Diffusion-Limited Aggregates. Under different experimental conditions (temperature and local dye concentration) the structure forms without interactions with other kinds of structures, and its equilibrium fractal dimension is smaller. The fractal dimension is thus not a universal property of the observed structures, but rather depends on the experimental conditions. [ABSTRACT FROM AUTHOR]

Provides information on the observation made on the biaxial switching between two topologically distinct textures of a nematic liquid crystal cell submitted to a strong electric field. Use of optical and electrical measurements; Model used to explain the experiment; Signficance of the texture changes induced by an applied weak electric field to most display applications of uniaxial nematic liquid crystals.