含开放金属位点MIL-101(Cr)掺杂的混合基质膜制备及其CO2分离性能

Preparation and CO_2 separation performance of mixed matrix membranes incorporated with open metal sites-containing MIL-101(Cr)

以结构中含有开放金属位点的MIL-101(Cr)作为填料与3种不同的聚合物复合制备了混合基质膜,从填料结构、聚合物性质及填料-聚合物界面状况等角度对混合基质膜的CO_2分离性能进行了分析。结果表明,由于MIL-101(Cr)较大的孔道尺寸以及结构中开放金属Cr(Ⅲ)位点与CO_2分子间的Lewis酸碱作用,其掺杂能够同时显著提高PSF膜的CO_2通量及分离因子。而当聚合物渗透性及选择性较高时,MIL-101(Cr)的掺杂仅提高了气体通量,CO_2分离因子则略有降低。当聚合物分子链柔性较大时,MIL-101(Cr)的表面孔道会被分子链堵塞,造成混合基质膜气体通量的显著下降。

Mixed matrix membranes（MMMs） were prepared by combining open metal sites-containing MIL-101（Cr） with three different kinds of polymers.CO2 separation performance of these prepared MMMs was further examined from the aspects of filler structure,polymer properties,and filler-polymer interface conditions.Benefiting from the large pore aperture and strong Lewis acid-base interactions between the open Cr（Ⅲ） sites and CO2 molecules,the incorporation of MIL-101（Cr） can greatly improve the gas permeability and separation factor of PSF membrane.The results indicate that when polymer with high selectivity and permeability is used,only the gas permeability is improved with the CO2 separation factor slightly decreased.When polymer with high chain mobility is used,the surface pores could be blocked by the polymer chains,leading to obvious decrease in gas permeability of the MMMs.