| abstract |
A porous PTFE membrane comprising a first porous surface and a second porous surface, and a bulk between the first porous surface and the second porous surface, wherein the porous PTFE membrane has a thickness of from about 2 nanometers to about 50 nanometers Wherein the first and second porous surfaces each comprise a ratio of unfused nodule area to at least about one fused nodule area, wherein the first and second porous surfaces each have a porosity rating of the porous PTFE membrane. |