  Thermally conductive nanopapers fabricated from graphene and related
materials are currently showing a great potential in thermal management
applications. However, thermal contacts between conductive plates represent the
bottleneck for thermal conductivity of nanopapers prepared in the absence of a
high temperature step for graphitization. In this work, the problem of
ineffective thermal contacts is addressed by the use of bifunctional
polyaromatic molecules designed to drive self-assembly of graphite nanoplates
(GnP) and establish thermal bridges between them. To preserve the high
conductivity associated to defect-free sp2 structure, non-covalent
functionalization with bispyrene compounds, synthesised on purpose with
variable tethering chain length, was exploited. Pyrene terminal groups granted
for a strong {\pi}-{\pi} interaction with graphene surface, as demonstrated by
UV-Vis, fluorescence and Raman spectroscopies. Bispyrene molecular junctions
between GnP were found to control GnP organization and orientation within the
nanopaper, delivering significant enhancement in both in-plane and cross-plane
thermal diffusivity. Finally, nanopapers were validated as heat spreader
devices for electronic components, evidencing comparable or better thermal
dissipation performance than conventional Cu foil, while delivering over 90%
weight reduction.
