| 摘要 |
A porous membrane that includes a first zone, the first zone including a crystallizable polymer; and a first nucleating agent, the first nucleating agent having a first concentration in the first zone, the first zone having a first average pore size; and a second zone, the second zone including a crystallizable polymer; and a second nucleating agent, the second nucleating agent having a second concentration in the second zone, the second zone having a second average pore size, wherein the crystallizable polymer is the same in the first zone and second zone, wherein the first average pore size is not the same as the second average pore size, wherein the first nucleating agent and the second nucleating agent are the same or different, wherein the first concentration and the second concentration agent are the same or different and with the proviso that the first nucleating agent and the first concentration are not the same as the second nucleating agent and the second concentration. Methods of making membranes are also disclosed. |
