This work is devoted to the development of high-flux ultrafiltration membranes using electrospun nanofibers of amphiphilic block copolymers (BCPs) of polystyrene-block-poly(2-vinylpyridine) (PS-b-P2VP) as building blocks. When soaked in hot ethanol, the solid as-spun BCP fibers are progressively transformed into three-dimensionally perforated fibers with increasing porosities with rising degrees of swelling, which ended up with the equilibrated morphology of spherical micelles. The BCP nanofibers are collected on macroporous substrates and subjected to heating to convert loosely stacked fibers to dense and continuous films. Subsequent swelling in hot ethanol leads to robust composite membranes with nanoporous BCP selective layers tightly adhered to the substrates. Filtration performances of the composite membranes can be conveniently modulated by electrospinning durations. The water permeabilities are as high as 6100 L m^–2 h^–1 bar^–1, which is ∼10–35 times higher than that of commercial membranes with similar rejections. Moreover, with the surface enrichment of P2VP chains the membranes exhibit a strikingly sharp pH-dependent water permeability switchable in the largest amplitude ever reported for multiple cycles. Electrospun fibers can be promising building materials to produce a wide range of membranes with 3D interconnected nanoporosities which also show great potential in separation and biomedical applications.

中文翻译：

---

电纺嵌段共聚物的选择性溶胀：从多孔纳米纤维到高通量和响应性超滤膜

这项工作致力于使用聚苯乙烯-嵌段-聚（2-乙烯基吡啶）（PS- b）两亲性嵌段共聚物（BCP）的电纺纳米纤维开发高通量超滤膜。-P2VP）作为构建基块。当浸入热乙醇中时，固态初生BCP纤维逐渐转变为三维多孔纤维，其孔隙率随溶胀度的升高而增加，最终形成了球形胶束形态平衡。BCP纳米纤维收集在大孔基材上，并进行加热，以将松散堆叠的纤维转化为致密且连续的薄膜。随后在热乙醇中溶胀导致坚固的复合膜，其纳米孔BCP选择性层紧紧粘附在基材上。复合膜的过滤性能可以通过电纺时间来方便地调节。透水率高达6100 L m ^–2 h ^–1 bar ^–1，这是具有类似排斥率的商业膜的约10-35倍。此外，随着P2VP链表面的富集，膜表现出了惊人的尖锐的pH依赖性水渗透性，可在多次循环中报道的最大振幅范围内切换。电纺纤维可以成为有前途的建筑材料，以生产具有3D互连纳米孔的多种膜，这些膜在分离和生物医学应用中也显示出巨大的潜力。