Linking CO2Sorption Performance to Polymer Morphology in Aminopolymer/Silica Composites through Neutron Scattering,Journal of the American Chemical Society

当前位置： X-MOL 学术 › J. Am. Chem. Soc. › 论文详情

Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)

Linking CO2Sorption Performance to Polymer Morphology in Aminopolymer/Silica Composites through Neutron Scattering
Journal of the American Chemical Society ( IF 14.4 ) Pub Date : 2015-09-02 , DOI: 10.1021/jacs.5b06823
Adam Holewinski ₁ , Miles A. Sakwa-Novak ₁ , Christopher W. Jones ₁

Affiliation

Composites of poly(ethylenimine) (PEI) and mesoporous silica are effective, reversible adsorbents for CO2, both from flue gas and in direct air-capture applications. The morphology of the PEI within the silica can strongly impact the overall carbon capture efficiency and rate of saturation. Here, we directly probe the spatial distribution of the supported polymer through small-angle neutron scattering (SANS). Combined with textural characterization from physisorption analysis, the data indicate that PEI first forms a thin conformal coating on the pore walls, but all additional polymer aggregates into plug(s) that grow along the pore axis. This model is consistent with observed trends in amine-efficiency (CO2/N binding ratio) and pore size distributions, and points to a trade-off between achieving high chemical accessibility of the amine binding sites, which are inaccessible when they strongly interact with the silica, and high accessibility for mass transport, which can be hampered by diffusion through PEI plugs. We illustrate this design principle by demonstrating higher CO2 capacity and uptake rate for PEI supported in a hydrophobically modified silica, which exhibits repulsive interactions with the PEI, freeing up binding sites.

中文翻译：

通过中子散射将 CO2 吸附性能与氨基聚合物/二氧化硅复合材料中的聚合物形态联系起来

聚(乙烯亚胺) (PEI) 和介孔二氧化硅的复合材料是有效的、可逆的 CO2 吸附剂，无论是从烟道气中还是在直接空气捕获应用中。二氧化硅内 PEI 的形态会强烈影响整体碳捕获效率和饱和率。在这里，我们通过小角度中子散射 (SANS) 直接探测支撑聚合物的空间分布。结合物理吸附分析的结构特征，数据表明 PEI 首先在孔壁上形成薄的保形涂层，但所有额外的聚合物聚集成沿孔轴生长的塞子。该模型与观察到的胺效率（CO2/N 结合比）和孔径分布趋势一致，并指出在实现胺结合位点的高化学可及性（当它们与二氧化硅强烈相互作用时无法进入）和质量传输的高可及性之间的权衡，这可能会受到通过 PEI 塞的扩散的阻碍。我们通过展示疏水改性二氧化硅支持的 PEI 具有更高的 CO2 容量和吸收率来说明这一设计原理，该二氧化硅表现出与 PEI 的排斥相互作用，释放结合位点。

更新日期：2015-09-02

点击分享查看原文

点击收藏

公开下载

阅读更多本刊新发论文本刊介绍/投稿指南