# Surface Modification of Poly(ethylene-alt-tetrafluoroethylene) by Atmospheric Pressure Dielectric Barrier Discharge Plasma

## TL;DR

This paper presents a method to improve the surface properties of a fluororesin membrane using plasma treatment, enhancing its usability in fabric composites.

## Contribution

A novel plasma modification strategy for ETFE membranes under atmospheric pressure is introduced, enhancing surface adhesion and hydrophilicity.

## Key findings

- Plasma modification significantly reduced the water contact angle of ETFE membranes from 96° to 50°.
- The T-peel strength of ETFE-polyester composites increased from 0.53 N/cm to 13.64 N/cm after modification.
- Modified ETFE membranes retained high T-peel strength (11.75 N/cm) even after ultrasonic washing.

## Abstract

The fluororesin membrane emerges as an ideal chemical-protective clothing material due to its excellent permeation resistance. However, using a fluororesin membrane with a low surface energy for compounding fabrics is very challenging. Herein, we demonstrate a strategy to modify the surface of a poly(ethylene-alt-tetrafluoroethylene) (ETFE) membrane by the atmospheric pressure dielectric barrier discharge (DBD) of plasma under different working voltages, processing times, and concentrations of acrylic acid (AA) in a helium (He) atmosphere. The increase in the hydrophilicity of the ETFE membrane is confirmed by the wettability test, which shows a significant decrease in the water contact angle, from 96° to 50°, after plasma modification. The interfacial T-peel strength of an ETFE membrane composited with polyester fabric increased from 0.53 N/cm to 13.64 N/cm after plasma modification. Significantly, the T-peel strength of the composite using a modified ETFE membrane with ultrasonic washing could still reach 11.75 N/cm. Various characterization methods clearly disclosed the physical and chemical changes on the ETFE membrane surface, such as introducing the polar -COOH group at a nano-level, improving the roughness, decreasing the ratios of the F/C element, and increasing the ratios of the O/C element, suggesting using nano-level grafted polyacrylic acid (g-PAA) on the surface of the membrane by DBD.