| abstract |
Asymmetric membranes comprising a first asymmetric porous zone including a first porous asymmetry that increases from the first exterior surface through the first porous zone of the bulk, and a second asymmetric porous zone including a second porous asymmetry that increases from the second exterior surface through the second porous zone of the bulk, wherein the first average pore size is larger than the second average pore size, as well as methods of making and using the membranes, are disclosed. |