Fluorine resin membranes with excellent chemical resistance have great potential for the application of high-performance chemical protective clothing. However, it is difficult to integrate fluorine resins into other materials such as fabrics due to their lower surface energy and poor bondability, making the fabrication of composite fabrics and the further seal splicing challenging. In this study, atmospheric pressure dielectric barrier discharge (DBD) plasma in helium (He) and helium/acrylic acid (He/AA) mixture atmospheres were used to modify two kinds of fluorine resins, ethylene tetrafluoroethylene (ETFE) and polytetrafluoroethylene (PTFE) membrane. The surface chemical properties, physical morphology, hydrophilicity and adhesion strength of the fluororesin membranes before and after plasma treatments were systematically analyzed. The results showed that the plasma treatment can modify the membrane surface at the nanoscale level without damaging the main body of the membrane. The hydrophilicity of the plasma-treated membrane was improved with the water contact angle decreasing from 95.83° to 49.9° for the ETFE membrane and from 109.9° to 67.8° for the PTFE membrane, respectively. The He plasma creates active sites on the membrane surface as well as etching the membrane surface, increasing the surface roughness. The He/AA plasma treatment introduces two types of polyacrylic acid (PAA)—deposited polyacrylic acid (d-PAA) and grafted polyacrylic acid (g-PAA)—on the membrane surface. Even after ultrasonic washing with acetone, g-PAA still existed stably and, as a result, improved the polarity and adhesion strength of fluororesin membranes. This work provides useful insights into the modification mechanism of DBD plasma on fluorine resins, with implications for developing effective strategies of integrating fluorine resin membrane to chemical protective clothing fabrics.

Chemical warfare agents (CWA) can poison people through the skin and cause injury, and the use of chemical protective clothing (CPC) is an important way to protect personnel from injury. CPC performance strongly depends on chemical protective materials, and satisfactory protective materials must meet various requirements, including protective performance, physiological comfort, mechanical performance, and cost effectiveness. Here, low-cost materials were used to prepare PVDF sodium sulfonate composite membranes with different contents of modified graphene oxide (GO-SSS). Their tensile properties, contact angle, permeability, and selectivity were tested and analyzed. The results show that when the addition ratio of GO-SSS to the bare membrane is 0.5%, the composite membrane has desirable permeation selectivity of water vapor/CWA simulant vapor and desirable mechanical properties. Hence, our sodium sulfonate composite membrane of PVDF with GO-SSS is an ideal material for potential applications in CPC.

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.