Enhanced dehumidification via hybrid hydrophilic/hydrophobic morphology having wedge gradient and drainage channels

Heat transfer performance under dehumidifying conditions for hydrophilic, and hybrid surfaces (hydrophilic/hydrophobic) within ambient are reported. The hybrid surface features star-shape morphology that contains hydrophilic interior inside star-shape while maintains a hydrophobic nature in the exterior of the star-shape. The star-shape offers comparatively good collecting capability of water condensate for its wedge gradient can effectively manipulate the surface energy. The mobility of the condensate within the star-shape interior is improved, leading to enhanced condensation heat transfer performance of 3.7~11.4% when compared to the hydrophilic surface. However, the contact angle hysteresis of the star-shape surface also retains the condensate inside the star-shape interior to some extent. To tackle this problem, a drainage channel alongside the gravity direction is added to the star-shape surface (star_I), and it offers a much better condensate removal, thereby improving the dehumidifying heat transfer performance up to 15.3~30.4%.