Highly efficient fabrication methods are urgently needed for high-performance materials that have a difficult environmental track record but cannot yet be replaced, such as fluoropolymers. Here we study the formation of hydrophobic nanocoatings by electrospraying PTFE nanopowder suspensions without additives, followed by thermal sintering. The spray expands electrostatically gradually, resulting in uniform crystalline sintered films, both on silicon and stainless steel. Besides characterizing the films’ morphology and crystallinity versus process parameters (by FIB-FESEM and XRD), we have found superior performance for PTFE-coated stainless-steel capillaries when used as electrospraying emitters with polymer solutions of low surface tension solvents.
Parajuli et al. (Tue,) studied this question.