Mixed‐matrix membrane (MMM) consisting of fillers in polymeric matrix offers a promising approach to develop high‐performance membranes, while remain challenges in achieving ideal filler dispersion and interfacial morphology. Herein, we reported on a new kind of MMM with molecular‐level dispersion of filler via a proposed reactive incorporation approach. Specifically, polyhedral oligomeric silsesquioxanes (POSS) with vinyl groups was grafted with ethoxy groups to build covalent bond with hydroxyl‐terminated polydimethylsiloxane (PDMS) chains to fabricate PDMS MMMs uniformly dispersed with POSS molecules. The molecular dispersion of POSS in PDMS matrix was visualized by SEM, AFM, and TEM characterizations, as well as reflected by XRD analysis. The PDMS chain conformation affected by the reactive incorporation of POSS was investigated by analyzing the thermal and mechanical properties of the POSS/PDMS MMMs using DSC, TGA, and DMA measurements. Contact angle test was used to study the surface affinity and positron annihilation technique was employed to probe the free volumes, which are respectively associated with the sorption and diffusion behavior in the POSS/PDMS MMMs. The results demonstrated that molecular cages and crosslinking effect of POSS led to an increase of large free volumes while a decline of small free volumes. Therefore, the PDMS MMM with reactive incorporation of only 2 wt.% POSS simultaneously enhanced the butanol permeability (by 78%) and butanol/water selectivity (by 124%) for pristine PDMS membrane, transcending the performance limit of state‐of‐the‐arts organophilic membranes. The proposed reactive incorporation approach may provide a platform of developing highly efficient membranes for molecular separation.

中文翻译：

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具有分子填料的PDMS混合基质膜通过反应性结合及其在从水溶液中回收生物丁醇中的应用

由聚合物基质中的填料组成的混合基质膜（MMM）为开发高性能膜提供了一种有前途的方法，同时在实现理想的填料分散和界面形态方面仍然存在挑战。在本文中，我们通过提出的反应性掺入方法报告了一种新型的具有分子水平分散剂的MMM。具体来说，将带有乙烯基的多面体低聚倍半硅氧烷（POSS）与乙氧基接枝，以与羟基封端的聚二甲基硅氧烷（PDMS）链建立共价键，以制造均匀分散在POSS分子上的PDMS MMM。通过SS，AFM和TEM表征，可以观察到POSS在PDMS基质中的分子分散，并通过XRD分析得以反映。通过使用DSC，TGA和DMA测量分析POSS / PDMS MMM的热和机械性能，研究了受POSS反应性结合影响的PDMS链构象。接触角测试用于研究表面亲和力，正电子an没技术用于探测自由体积，自由体积分别与POSS / PDMS MMM中的吸附和扩散行为有关。结果表明，POSS的分子笼和交联作用导致较大的自由体积增加，而较小的自由体积下降。因此，反应性掺入仅2 wt。％POSS的PDMS MMM同时提高了原始PDMS膜的丁醇渗透性（提高了78％）和丁醇/水选择性（提高了124％），超越了最先进的亲有机膜的性能极限。所提出的反应性掺入方法可以提供开发用于分子分离的高效膜的平台。