Few-layer graphene on nickel enabled sustainable dropwise condensation

Condensation is critical for a wide range of applications such as electrical power generation, distillation, natural gas processing, dehumidification and water harvest, and thermal management. Compared with filmwise mode of condensation (FWC) prevailing in industrial-scale systems, dropwise condensation (DWC) can provide an order of magnitude higher heat transfer rate owing to drastically reduced thermal resistance from the formation of discrete and mobile droplets. In the past, promoting DWC by controlling surface wetting has attracted wide attention, but DWC highly relies on non-wetting surfaces and only lasts days under practical conditions due to the poor reliability of coatings. Here, we developed nanostructured graphene coatings on nickel (Ni) substrates that we can control and enhance the nucleation of water droplets on graphene grain boundaries. Surprisingly, this enables DWC even under normal wetting conditions. This is contradictory to the widely accepted DWC mechanism. Moreover, the Nigraphene surface enables exceptional long-term condensation from days to more than 3 years under practical or even more aggressive testing environments. (c) 2021 Science China Press. Published by Elsevier B.V. and Science China Press. All rights reserved.

Automated summary

A new nanostructured graphene coating has been developed to achieve dropwise condensation even under normal wetting conditions, significantly improving the reliability and long-term effect of condensation.