Abstract:
Lubricant-infused surfaces (LIS) are highly efficient in repelling water and constitute a very promising
family of materials for condensation processes occurring in a broad range of energy applications. However, the
performance of LIS in such processes is limited by the inherent thermal resistance imposed by the thickness of the
lubricant and supporting surface structure, as well as by the gradual depletion of the lubricant over time. Here, we
present an ultrathin (∼70 nm) and conductive LIS architecture, obtained by infusing lubricant into a vertically
grown graphene nanoscaffold on copper. The ultrathin nature of the scaffold, combined with the high in-plane
thermal conductivity of graphene, drastically minimize earlier limitations, effectively doubling the heat transfer
performance compared to a state-of-the-art CuO LIS surface. We show that the effect of the thermal resistance to the
heat transfer performance of a LIS surface, although often overlooked, can be so detrimental that a simple
nanostructured CuO surface can outperform a CuO LIS surface, despite filmwise condensation on the former. The
present vertical graphene LIS is also found to be resistant to lubricant depletion, maintaining stable dropwise
condensation for at least 24 h with no significant change of advancing contact angle and contact angle hysteresis.
The lubricant consumed by the vertical graphene LIS is 52.6% less than that of the existing state-of-the-art CuO LIS,
also making the fabrication process more economical.
