Hyperbolic Graphene Framework with Optimum Efficiency for Conductive Composites

Constructing conductive filler networks with high efficiency
is
essential to fabricating functional polymer composites. Although two-dimensional
(2D) sheets have prevailed in nanocomposites, their efficiency in
enhancing conductive functions seems to reach a limit, as if merely
addressing the dispersion homogeneity. Here, we exploit the unrecognized
geometric curvature of 2D sheets to break the efficiency limit of
filler systems. We introduce the hyperbolic curvature concept to mediate
the incompatibility between 2D planar topology and 3D filler space
and hold the efficient conductive path through face-to-face contact.
The hyperbolic graphene framework exhibits a record efficiency in
enhancing electrically and thermally conductive functions of nanocomposites.
At a volume loading of only 1.6%, the thermal and electrical conductivities
reach 31.6 W/(mK) and 13 911 S/m, respectively. We demonstrate
that the conductive nanocomposites with a hyperbolic graphene aerogel
framework are useful for thermal management, sensing, and electromagnetic
shielding. Our work provides a solution to reconcile the incompatibility
between the 2D planar structure of sheets and the highly expected
3D conductive path, presenting a geometrically optimal filler system
to break the efficiency limit of multifunctional nanocomposites and
broaden the structural design space of 2D sheets by curvature modulation
to meet more applications.