The intercalation of polypyrrole (ppy) into hexagonal mesostructured carbon at 6.80-1.2.6 wt.-% levels results in substantial shrinkage of the framework structure (Deltad(100) = 0.8-1.0 nm) and the pore size (from 3.7 nm initially to 2.9-2.5 nm upon ppy binding). The surface areas (718-960 m(2)g(-1)) and electrical conductivities (0.1-1.0 S cm(-1)) for compressed powders, however, are largely retained over a wide temperature range, providing potential applications in sensing.