Analysis of Long-Term Hydrophobic Properties Stability of the Textured Polymer Coatings Produced via Electron-Beam Deposition of Polymers on the Track-Etched Membrane Surface

The stability of the hydrophobic properties of coatings with textured surfaces made of polytetrafluoroethylene and ultra-high molecular weight polyethylene during storage, as well as during prolonged contact with water and aqueous solutions of sodium chloride has been studied. Polymeric coatings were applied to the surface of a polyethylene terephthalate track-etched membrane by electron-beam deposition to produce composite membranes for water desalination. It is found that polytetrafluoroethylene coatings tend to age under the influence of real environmental conditions and gradually lose their hydrophobic properties. The water contact angle of these coatings decreases during storage samples of composite membranes. In contrast, the water contact angle of ultra-high molecular weight polyethylene coatings practically does not change during storage of membrane samples. A study of the stability of polymeric coatings during prolonged contact of composite membranes with water and aqueous solutions of sodium chloride showed that coatings made of ultra-high molecular weight polyethylene are stable both in water and in aqueous solutions of sodium chloride. Polytetrafluoroethylene coatings are more stable to the action of aqueous salt solutions than water.