Disordered Triblock Polymers for Nanoporous Materials with Tunable Surface Properties for Ultrafiltration Applications
Disordered Triblock Polymers for Nanoporous Materials with Tunable Surface Properties for Ultrafiltration Applications
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DOI：
10.1021/acsapm.2c00065
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发表时间：
2022-04
影响因子：
5
通讯作者：
W. Y. Chan;M. Hillmyer
中科院分区：
文献类型：
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作者：
W. Y. Chan;M. Hillmyer
以三嵌段聚合物为前驱体制备纳米多孔超滤膜。探索的三嵌段是聚（丙交酯）-b-聚（低聚乙二醇甲基醚甲基丙烯酸酯）-b-聚（苯乙烯-s-甲基丙烯酸甲酯）（PLA-POEGMA-PSMMA），其中PLA是可蚀刻的成孔嵌段，POEGMA是亲水性孔衬里嵌段，PSMMA是基质嵌段。通过加热聚合物熔体高于有序-无序转变温度（TODT），然后在玻璃化转变温度（Tg）以下淬火，或通过在环境条件下旋涂嵌段聚合物溶液等温地获得双连续微相分离域。POEGMA可与PLA混溶，但不与PSMMA混溶，因此应与PLA共定位，并在选择性PLA蚀刻后暴露在孔表面上。三嵌段聚合物具有与二嵌段聚合物类似的ODT行为，并且熔体中可接近的TOD的存在强烈地依赖于偏析强度χPLA-PSMMAN。通过将三嵌段聚合物旋涂到水填充的尼龙膜上来制备具有嵌段聚合物选择性层的复合膜，其中快速溶剂蒸发使得嵌段聚合物能够在无序状态下玻璃化。所得膜具有均匀的表面孔，高渗透性，和表面亲水性的小的改善，并且该方法可以应用于靶向其他表面功能。
Triblock polymers trapped in the fluctuating disordered state were investigated as precursors to nanoporous ultrafiltration membranes. The triblock explored is poly(lactide)-b-poly(oligoethylene glycol methyl ether methacrylate)-b-poly(styrene-s-methyl methacrylate) (PLA-POEGMA-PSMMA), where PLA is the etchable pore-forming block, POEGMA is the hydrophilic pore-lining block, and PSMMA is the matrix block. Bicontinuous microphase-separated domains were obtained thermally by heating the polymer melt above the order–disorder transition temperature (TODT) followed by quenching below the glass transition temperature (Tg), or isothermally by spin coating the block polymer solution at ambient conditions. POEGMA is miscible with PLA but not PSMMA and should therefore colocalize with PLA and be exposed on pore surfaces after selective PLA etching. The triblock polymers have similar ODT behavior as diblock polymers, and the presence of an accessibleTODTin the melt depends strongly on the segregation strength χPLA-PSMMAN. Composite membranes with block polymer selective layers were prepared by spin coating the triblock polymer onto water-filled nylon membranes, where rapid solvent evaporation enabled the block polymer to be vitrified in the disordered state. The resulting membranes have uniform surface pores, high permeabilities, and small improvements in surface hydrophilicity, and the approach may be applied to target other surface functionalities.