Substrate with Graphene-based Layer

(canceled)

4-5. (canceled)

A barrier article comprising

• a substrate and
• a continuous graphene-based layer adhered to the surface of the substrate, wherein the continuous graphene-based layer includes cross-linked graphene-based planar sheets and is substantially impermeable to transmission of a small molecule through the graphene-based layer.

9-12. (canceled)

15-18. (canceled)

A method of making a barrier article comprising

• contacting a liquid solution of graphene-based sheets to a substrate, and
• drying the liquid solution to produce a continuous graphene-based layer adhered to the surface of the substrate, wherein the continuous graphene-based layer is substantially impermeable to transmission of small molecules through the graphene-based layer.

20-22. (canceled)

26-29. (canceled)

31-34. (canceled)

37-41. (canceled)

43-116. (canceled)

A method of containing environmental toxicants on one side of a barrier article comprising

• placing the barrier article over an environmentally hazardous condition wherein the barrier article inhibits movement of environmental toxicants in the environmentally hazardous condition into the environment, and
• wherein the barrier article includes a substrate including a landfill liner, a landfill cap, a vertical subsurface containment barrier, a subsurface permeable reactive barrier, a vapor intrusion barrier, a tarp barrier or an RCRA cap and
• a continuous graphene-based layer adhered to the surface of the substrate, wherein the continuous graphene-based layer is substantially impermeable to transmission of the environmental toxicants through the graphene-based layer.

The barrier article of claim 9 wherein the crosslinker is a dihydrazide, diazide, polyamine, triethylenetetraamine, polyamide, or epoxide.