Key Laboratory of Textile Science & Technology, Ministry of Education, College of Textiles, Donghua University , Shanghai 201620, China.
Innovation Center for Textile Science and Technology, Donghua University , Shanghai 200051, China.
ACS Appl Mater Interfaces. 2017 Nov 22;9(46):41087-41098. doi: 10.1021/acsami.7b14635. Epub 2017 Nov 8.
Amine-containing sorbents have been extensively studied for postcombustion carbon dioxide (CO) capture because of their ability to chemisorb CO from the flue gas. However, most sorbents are in the form of powders currently, which is not the ideal configuration for the flue gas separation because of the fragile nature and poor mechanical properties, resulting in blocking of the flow pipes and difficult recycling. Herein, we present a novel approach for the facile fabrication of flexible, robust, and polyethyleneimine-grafted (PEI-grafted) hydrolyzed porous PAN nanofibrous membranes (HPPAN-PEI NFMs) through the combination of electrospinning, pore-forming process, hydrolysis reaction, and the subsequent grafting technique. Excitingly, we find that all the resultant porous PAN (PPAN) fibers exhibit a balsam-pear-skin-like porous structure due to the selective removal of poly(vinylpyrrolidone) (PVP) from PAN/PVP fibers by water extraction. Significantly, the HPPAN-PEI NFMs retain their mesoporosity, as well as exhibit good thermal stability and prominent tensile strength (11.1 MPa) after grafting, guaranteeing their application in CO trapping from the flue gas. When exposed to CO at 40 °C, the HPPAN-PEI NFMs show an enhanced CO adsorption capacity of 1.23 mmol g (based on the overall quantity of the sample) or 6.15 mmol g (based on the quantity of grafted PEI). Moreover, the developed HPPAN-PEI NFMs display significantly selective capture for CO over N and excellent recyclability. The CO capacity retains 92% of the initial value after 20 adsorption-desorption cycle tests, indicating that the resultant HPPAN-PEI NFMs have good long-term stability. This work paves the way for fabricating NFM-based solid adsorption materials endowed with a porous structure applied to efficient postcombustion CO capture.
含胺吸附剂因其能够从烟道气中化学吸附 CO 而被广泛研究用于燃烧后 CO2 的捕获。然而，目前大多数吸附剂都呈粉末状，由于其易碎性和较差的机械性能，不适合烟道气分离，会导致流道堵塞和难以回收。在此，我们通过静电纺丝、造孔过程、水解反应以及随后的接枝技术，提出了一种简便的制备柔性、坚固且接枝聚乙烯亚胺的水解多孔 PAN 纳米纤维膜（HPPAN-PEI NFMs）的新方法。令人兴奋的是，我们发现由于通过水萃取从 PAN/PVP 纤维中选择性地去除了聚（N-乙烯基吡咯烷酮）（PVP），所有得到的多孔 PAN（PPAN）纤维均呈现出香瓜皮样的多孔结构。重要的是，HPPAN-PEI NFMs 在接枝后保持其介孔性，并且表现出良好的热稳定性和突出的拉伸强度（11.1 MPa），保证了它们在烟道气中 CO 捕集方面的应用。当在 40°C 下暴露于 CO 时，HPPAN-PEI NFMs 显示出增强的 CO 吸附容量为 1.23 mmol g（基于样品的总量）或 6.15 mmol g（基于接枝的 PEI 的量）。此外，所开发的 HPPAN-PEI NFMs 对 CO 相对于 N2 具有明显的选择性捕获能力和出色的可回收性。在 20 次吸附-解吸循环测试后，CO 容量保留了初始值的 92%，表明所得 HPPAN-PEI NFMs 具有良好的长期稳定性。这项工作为制造基于 NFM 的具有多孔结构的固体吸附材料铺平了道路，这些材料可用于高效的燃烧后 CO 捕获。
