Superwettability integration: concepts, design and applications

Functional surfaces exhibiting superwettability offer great opportunities to develop advanced science and technology. To unite the advantages of different surfaces with special wettability, superwettability integration has been proposed and fabricated, showing a co-operative and complementary effect on material properties. This paper discusses how to combine different wettabilities and what functions can be achieved based on superwettability integration. Superwettability integration is defined as a unified system combining different superwetting materials or assembling superwetting materials with other functional materials. Four types of superwettability integrations are summarized: (a) surfaces with microscopic wettability patterns, (b) surfaces with macroscopic wettability patterns, (c) Janus interface materials with asymmetric wettability and (d) surfaces with specific wettability boundary. The functions and applications of the integrated systems are reviewed, particularly for use in fluid control, vapor condensation, fog collection and so on. The principle of designing the integration is also depicted as manipulating the significant difference in surface energy between two surfaces. On the basis of current research, some of the possible designs are finally proposed and a prospect of multifunctional superwettability integration is made.