New hydrophobic materials based on poly(tetrafluoroethylene-co-vinylidene fluoride) fiber

The structural features of poly(tetrafluoroethylene-co-vinylidene fluoride) (F42) nonwovens with electrospun fibers were studied by scanning electron microscopy (SEM), atomic force microscopy (AFM), and standard contact porosimetry (SCP). Thermal pressing modification of polymeric nonwovens was considered. Such modification allows variation in their surface morphology and water wettability of these surfaces, which demonstrates the possibility for preparation of materials with a wetting gradient. For the starting and modified samples, we studied in detail how the contact angle evolves with an increase in the aqueous phase contact time, as well as how the wettability of materials immersed in water changes after repeated crystallization and melting of water. The morphological structural features of nonwovens formed by poly(tetrafluoroethylene-co-vinylidene fluoride) microfibers were revealed. The method for the thermal pressing modification of materials was proposed and the effects of modification on the structures, wettability, and water sorption of materials were studied. The materials were found to be highly hydrophobic and promising for the design of samples with gradient wettability. © 2016, Pleiades Publishing, Ltd.