Hybrid Graphene Oxide/Crumpled Graphene Film via Subcooled Boiling-Induced Self-Assembly for Highly Efficient Boiling Heat Transfer

Abstract Graphene-based films generated on the substrate can modify surface structure and chemistry to enable the improvement in heat transfer capacity for many important boiling-related applications. Current methods for preparing these films, however, require additional processing equipment and involve relatively complex processes. Achieving the simple and controllable generation of these films remains a great challenge. In this work, we develop a facile subcooled boiling-induced self-assembly (SBISA) method for generating graphene-based films. We first explore the SBISA mechanism, and demonstrate the formation of the graphene-based films under the action of a combined force induced by the capillary pressure, structural disjoining pressure and vapor recoil force. In addition, using the SBISA process we generate a tunable hybrid graphene oxide (GO)/crumpled graphene (CG) film with mixed wettability. The hybrid GO/CG film enables large performance enhancements for boiling with 150.0% increase in critical heat flux (CHF) and 163.9% increase in maximum heat transfer coefficient (HTC) over the pristine copper surface. This SBISA strategy provides an alternative approach for fabricating tunable films with hierarchical structure and mixed wettability on various substrates, and it may also help produce surfaces with different micro/nanostructures for enhancing phase-change based heat transfer.