关键词: 膜, CO2分离, 共混, 聚乙二醇二甲醚, 渗透选择性

Abstract: Membrane technology is widely used in the field of CO2 separation due to its characteristics of low investment and simple equipment. The core of membrane technology is the material. According to research，the existence of ethylene oxide (EO) in polymer can effectively improve CO2 permeability and selectivity. Polyethylene glycol dimethyl ether (PEGDME)，a promising material for CO2 separation，is rich of EO units，and its methyl end groups provide higher CO2 diffusivity. The polyethylene glycol dimethyl ether (PEGDME) was proposed to blend with PVDF as a selective layer for CO2 in this study，and the PEGDME-PVDF blend selective layer was fabricated on a porous support layer of polypropylene (PP) by solvent evaporation method to manufacture PEGDME-PVDF/ PP composite membranes for CO2 separation. With the increase of PEGDME content in the blend membrane，both CO2 permeability and CO2/N2 selectivity tend to rise. When the content of PEGDME reached 50wt%，CO2 permeability was 42.9GPU and CO2/N2 selectivity was 47.5. With the increase of PVDF concentration，CO2 permeability tended to decrease while CO2/N2 selectivity increased slowly. With the decrease of solvent evaporation temperature，PVDF crystallization decreased accordingly，and better membrane performance can be obtained. At solvent temperature of 30℃，the PEGDME- PVDF blend membrane performed excellently with CO2 permeation rate up to 84.7GPU，and the CO2/N2 selectivity was as high as 47.2.

Key words: membrane, CO2 separation, blend, PEGDME, perm-selectivity