UNS: Spatial Control of Condensate and Wetting Regimes using Heterogeneous and Hierarchical Surface Structures for Enhanced Heat Transfer

Drexel University, Philadelphia PA

Investigators

Abstract

CBET - 1511453 PI: McCarthy, Matthew The goals of this project are to develop heterogeneous surface structures and investigate effects of spatially varying surface wettability and thermal conductivity on wetting and heat transfer rates during condensation. The project seeks to improve heat transfer rates by maintaining precise control of the liquid-vapor interfaces and segregating wetted and non-wetted regions on engineered surfaces. Thus, results of the project could improve the design of heat transfer systems and increase energy efficiency for a variety of applications, including electronics cooling, desalination and water purification, and chemical processing. The project will involve graduate and undergraduate students, and outreach activities are planned to engage local students, especially those from under-represented groups. The project will combine bio-templated nanofabrication techniques and initiated chemical vapor deposition (iCVD) to create heterogeneous surfaces with patterned variations in wettability and thermal conductivity. The bio-templating process uses self-assembly and metallization of the Tobacco mosaic virus to create a uniform layer of high surface area nanostructures. iCVD is used to coat the nanostructured surfaces with thin layers of low surface energy polymeric materials. The combination of mixed wettability and mixed conductivity will provide spatial control over condensate droplets to enhance heat transfer. The investigators will use confocal scanning laser microscopy and high-speed imaging during condensation and condensate removal to characterize the performance of surfaces and the effects of heterogeneous architectures. Results could guide practitioners in improving condensation heat transfer rates by enabling precise control over condensate dynamics.