In-depth diffusion of oxygen into LDPE exposed to an Ar--O2 atmospheric post-discharge: a complementary approach between AR-XPS and Tof-SIMS techniques

TL;DR

This study investigates how oxygen diffuses into low density polyethylene during atmospheric plasma treatment, using complementary AR-XPS and ToF-SIMS techniques to analyze surface and bulk properties.

Contribution

It combines AR-XPS and ToF-SIMS to provide a detailed analysis of oxygen diffusion depth and surface chemistry changes in LDPE after plasma exposure.

Findings

Oxygen can penetrate up to 20-40 nm into LDPE.

Good correlation between XPS and FTIR analyses.

Oxygen diffusion depends on plasma treatment parameters.

Abstract

The in-depth oxygen diffusion into a low density polyethylene film is performed in the post-discharge of an atmospheric plasma torch, supplied in argon as carrier gas and with or without oxygen as reactive gas. The chemical and structural properties of the polymer surface and bulk are studied in terms of plasma parameters (treatment time, power, and reactive gas flow rate). A good correlation between XPS and Fourier transform infrared spectroscopy analyses is demonstrated. The penetration depth of oxygen into the bulk of the polymer is investigated by angle resolved-XPS and time-of-flight SIMS. It is shown that, depending on the plasma conditions, oxygen could penetrate up to 20--40 nm into the low density polyethylene during the atmospheric plasma treatment.