Polymer-based membranes play a key role in several industrially important gas separation technologies, e.g., removing CO₂ from natural gas, with enormous economic and environmental impact. Here, we develop a novel hybrid membrane construct comprised entirely of nanoparticles grafted with polymers. These membranes are shown to have broadly tunable separation performance through variations in graft density and chain length. Computer simulations show that the optimal NP packing forces the grafted polymer layer to distort, yielding regions of measurably lower polymer density. Multiple experimental probes confirm that these materials have the predicted increase in “polymer free volume”, which explains their improved separation performance. These polymer-grafted NP materials thus represent a new template for rationally designing membranes with desirable separation abilities coupled with improved aging characteristics in the glassy state and enhanced mechanical behavior.

中文翻译：

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具有可控自由体积的聚合物接枝纳米颗粒膜

基于聚合物的膜在多种工业上重要的气体分离技术中起着关键作用，例如，去除CO ₂天然气，具有巨大的经济和环境影响。在这里，我们开发了一种新型的杂化膜构建体，该构建体完全由接枝有聚合物的纳米颗粒组成。这些膜通过接枝密度和链长的变化显示具有广泛可调的分离性能。计算机模拟表明，最佳的NP堆积会迫使接枝的聚合物层变形，从而产生可测量的较低聚合物密度的区域。多个实验探针证实了这些材料在“无聚合物体积”方面具有预期的增长，这说明了它们改善的分离性能。因此，这些聚合物接枝的NP材料代表了一种合理设计膜的新模板，该膜具有理想的分离能力，并具有改善的玻璃态老化特性和增强的机械性能。