Формирование на поверхности трековых мембран гидрофобных покрытий методом магнетронного распыления полимеров в вакууме

Abstract

The surface properties and chemical structure of nanoscale coatings deposited on the poly(ethylene terephthalate) track-etched membranes surface by magnetron sputter deposition of ultra-high molecular weight polyethylene and polytetrafluoroethylene in vacuum are studied. It is shown that the application of coatings leads to hydrophobization of membrane surface, the degree of which depends on the type of polymer used for sputtering and the thickness of the coating. It is established that the use of this modification method leads to smoothing of structural inhomogeneities of the membrane surface layer. This result is explained by the deposition of coatings in the pore channels at a certain depth from the entrance and the overlap of pores on the surface of modified membranes. Besides, the deposition of coatings on the track-etched membrane surface leads to a change in the pore shape. The diameter of the pores on the untreated side of the membranes remains unchanged and decreases significantly on the modified side. The pores of the membranes acquire an asymmetric (conical) shape in this case. The study of the chemical structure of coatings by X-ray photoelectron spectroscopy showed that they contain oxygen-containing functional groups due to the oxidation of the polymer matrix. The developed composite membranes can be used in the membrane distillation processes for the desalination of seawater.