Water-repellent hierarchical microstructured PTFE films via micro powder hot embossing

The preparation of hierarchical microstructured surfaces to obtain different wettability has been studied in both academy and industry. Polytetrafluoroethylene (PTFE) is an ideal material for preparing superhydrophobic surface due to its ultra-low surface energy. However, it is still a challenge to prepare hierarchical structure on the surface of PTFE. In this paper, PTFE films with hierarchical structure were successfully prepared by micro powder hot embossing (mPHE) process. Through characterization, the maximum contact angle and minimum sliding angle can reach up to 164° and 5.3° respectively. The influence of processing parameters and particle size on forming qualities was discussed. A dimensionless indicator was proposed to successfully describe the hierarchical character and characterize the relationship between wetting states and forming quality. Finally, a series of mechanical and chemical durability tests were carried out, verifying the practical application value of the prepared PTFE films.