Fabrication of Fog-Harvesting Polymer Films by Nanoimprint Lithography

Abstract

A high-efficiency fog-harvesting polymer films were fabricated by hot-embossing and coating with a hydrophobic self-assembled monolayer. This fabrication process is simple and cost-effective, and can be applied to large-area fabrication. Films with various hydrophilic/hydrophobic patterns were made using photomasks which have micro-sized dots, branches and mesh patterns. Contact angles of fog-harvesting films were measured and the fog-harvesting throughput of films was tested to find the effectiveness of patterns for fog-harvesting. In result, the dot-patterned hydrophobic/hydrophilic polymer films with moth-eye nano-structures showed the highest fog-harvesting efficiency. Furthermore, the efficiency of the dot-patterned fog-harvesting polymer film was enhanced by approximately 200% in comparison with that of the bare fog-harvesting polymer film.