Suspensions of colloids, thermotropic low molecular weight liquid crystal, and small amounts of alkane are investigated by laser scanning confocal microscopy and calorimetry. While cooling the suspension through the isotropic-nematic phase transition the colloidal particles are expelled by the liquid crystal, causing the formation of a three-dimensional particle network. Upon reheating back into the isotropic phase the network may break up. However, taking the sample a number of times through the cooling/heating cycle leads to annealing of the network, accompanied by an increase of the loss modulus of the system by several orders of magnitude. Eventually it hardly breaks up, even after resting in the isotropic phase for several hours. Calorimetric studies reveal that in this case, the temperature dependent heat capacity of the system contains two peaks.
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