Institute of Polymer Research, Helmholtz-Zentrum Geesthacht, Max-Planck-Str. 1, 21502, Geesthacht, Germany.
Institute of Physical Chemistry, University of Hamburg, Martin-Luther-King-Platz 6, 20146, Hamburg, Germany.
Macromol Rapid Commun. 2019 Feb;40(3):e1800729. doi: 10.1002/marc.201800729. Epub 2018 Nov 12.
Isoporous integral asymmetric membranes derived from the self-assembly of block copolymers combined with the non-solvent-induced phase separation (SNIPS) have gained great attention. To extend their utility, good control over pore size and surface functionality in a facile manner is highly desirable. Here, an approach is proposed to achieve this by quaternization of the poly(4-vinylpyridine) moiety of a polystyrene-block-poly(4-vinylpyridine) SNIPS membrane using alkyl iodides via a scalable gas-solid heterogeneous reaction. By changing the size of the alkyl groups of the quaternization agent and the degree of quaternization, the effective pore size of the membrane is tailored in a wide range from the ultrafiltration to the nanofiltration regime. A quaternization of approximately half of the 4VP repeating units of the membranes with methyl iodide, ethyl iodide, or 1-propyl iodide leads to a retention of methylene blue from a 10 mg L aqueous solution of 96%, 87%, and 83%, respectively.
由嵌段共聚物自组装结合非溶剂致相分离（SNIPS）衍生而来的等孔整体不对称膜受到了极大的关注。为了扩展其用途，以简单的方式对孔径和表面功能进行良好的控制是非常理想的。在这里，提出了一种通过使用烷基碘化物在 SNIPS 膜的聚苯乙烯嵌段-聚（4-乙烯基吡啶）部分进行季铵化，从而实现这一目标的方法，该方法通过可扩展的气-固多相反应进行。通过改变季铵化试剂的烷基大小和季铵化程度，可以在超滤到纳滤的宽范围内对膜的有效孔径进行调整。用甲基碘、乙基碘或 1-丙基碘对膜的约一半的 4VP 重复单元进行季铵化，分别导致对来自 10mg/L 水溶液的亚甲蓝的保留率为 96%、87%和 83%。
