8th Liquid Matter Conference September 6-10, 2011 Wien, Austria ...

Fri 911:10-14:00P3.31Fractal aggregates evolution of methyl red in liquidcrystalLuca Sorriso-Valvo, 1 Federica Ciuchi, 1 Alfredo Mazzulla, 2 and José ManuelRedondo 31 IPCF-CNR, ponte P. Bucci, cubo 31C, 87036, rende (CS), Italy2 IPCF-CNR, rende (CS), Italy3 Departament di Fisica Aplicada, Universitat Politecnica de Catalunya, Barcelona,SpainThe spontaneous formation of dendritic aggregates is observed in a two-dimensional confined layeredsystem consisting of a film composed of liquid crystal, dye and solvent cast above a polymersubstrate. The observed aggregates are promoted by phase separation processes induced by dyediffusion and solvent evaporation. The growth properties of the aggregates are studied through thetemporal evolution of their topological properties (surface, perimeter, fractal dimension). The fractaldimension of the completely formed structures, when they are coexistent with different types ofstructures, is consistent with theoretical and experimental values obtained for Diffusion-LimitedAggregates. Under different experimental conditions (temperature and local dye concentration)the structure forms without interactions with other kinds of structures, and its equilibrium fractaldimension is smaller. The fractal dimension is thus not a universal property of the observedstructures, but rather depends on the experimental conditions.31