Preparation of heparin-like surfaces by introducing sulfate and carboxylate groups on poly(ethylene) using an argon plasma treatment

Abstract

Carboxylate and sulfate groups were introduced at the surface of poly(ethylene) (PE) samples.This was accomplished by coating and immobilizing sodium 10-undecenoate (C11(:)) and 10-undecenesulfate (S11(:)) on the polymer by means of an argon plasma treatment. The composition of the coatedsurfactant layer was proportional to the composition of the coating solution. The thickness of the surfactantlayer on the surface of PE samples, which were precoated from an aqueous solution with a total surfactantconcentration of 0.30 M, was about 55 A°. The presence of carboxylate and sulfate groups after plasmatreatment of the precoated surfaces was confirmed by X-ray photoelectron spectroscopy (XPS). About20% of the initial amount of functional groups of the coated surfactants was retained at the PE surface.The ratio of carboxylate/ sulfate groups at the plasma treated surfaces was dependent on the compositionof the precoated surfaces. The minimum surface density of these groups on the resulting samples wasabout one group per 40 A°2.