Do surfaces with mixed hydrophilic and hydrophobic areas enhance pool boiling?

TLDR

The study characterized various networks of hydrophilic and hydrophobic regions to assess their impact on pool boiling. Surfaces with mixed hydrophilic/hydrophobic patterns increase critical heat flux by up to 65 % and heat transfer coefficients by up to 100 %, especially hydrophilic networks with hydrophobic islands that suppress insulating vapor layers.

Abstract

We demonstrate that smooth and flat surfaces combining hydrophilic and hydrophobic patterns improve pool boiling performance. Compared to a hydrophilic surface with 7 degree wetting angle, the measured critical heat flux and heat transfer coefficients of the enhanced surfaces are up to respectively 65 and 100% higher. Different networks combining hydrophilic and hydrophobic regions are characterized. While all tested networks enhance the heat transfer coefficient, large enhancements of critical heat flux are typically found for hydrophilic networks featuring hydrophobic islands. Hydrophilic networks indeed are shown to prevent the formation of an insulating vapor layer.