Poly(tetrafluoroethylene) sputtering in a gas aggregation source for fabrication of nano-structured deposits
Abstract
R. f. magnetron sputtering of poly(tetrafluoroethylene) in configuration of a gas aggregation source is shown to produce super-hydrophobic nano-structured coatings in which cross-linked nano-particles of fluorocarbon plasma polymer are embedded in an uncross-linked continuous (-CF2-)(x), matrix. The 20-30 nm nano-particles appear in proximity of the magnetron and have cross-linked structure as a result of fast random radical recombination in the plasma.
The continuous phase is formed at remote distances from the magnetron as a result of slower step-growth gas phase polymerization of CF2 bi-radicals. The matrix has highly crystalline structure in which the CF2 groups tend to adopt a 15/7 helical configuration.
At least part of the macromolecules constituting the polymeric phase are oligomers with the molar mass below 1400 g/mol.