Breathable Vapor Toxicant Barriers Based on Multilayer Graphene Oxide

Area of Science:

• Materials Science
• Nanotechnology
• Chemical Engineering

Background:

• Graphene oxide (GO) membranes are investigated for their potential as molecular barriers and sieves.
• GO films exhibit moisture-responsive expansion, enabling water permeation while maintaining barrier properties.

Purpose of the Study:

• To evaluate GO membranes as water-breathable barrier layers for personal protective equipment (PPE).
• To assess the capability of GO membranes to block chemical toxicants during simulated perspiration.

Main Methods:

• Development of a device to measure toxicant permeation rates under counter-current water flow simulating perspiration.
• Testing with trichloroethylene (TCE), benzene, and ethanol to model small-molecule toxicant transport.
• Application of a molecular transport model to understand permeation mechanisms.

Main Results:

• Submicron GO membranes demonstrated effective barrier performance against TCE, outperforming current technologies.
• Permeation of benzene and ethanol was higher than TCE, correlating with water solubility and molecular size.
• Molecular transport modeling indicated toxicant permeation occurs through oxidized domains with hydrogen-bonded water phases.

Conclusions:

• GO membranes show promise as breathable barriers for PPE, offering protection against certain small-molecule toxicants.
• Performance varies with toxicant properties; high water solubility and small molecular size favor permeation.
• GO films provide high water breathability and broad toxicant exclusion, with specific efficacy against small molecules like TCE.