Anomalous decrease of the specific heat capacity at the electrical and thermal conductivity percolation threshold in nanocomposites

We report an unusual specific heat variation in nanotube/polymer composites, related to a reduction in its value at the electrical and the thermal conductivity percolation threshold, with a concomitant increase in the crystallinity. The reduction has been interpreted in terms of the partition of the total number of nanostructures into isolated or clustered/connected entities, the numbers of which vary as a function of the nanotube filler fraction, and the consequent modulation of the entropic characteristics as well as the conductivity.