论文部分内容阅读
Membrane technology is a viable energy-saving alternative for CO2 separation.The blending of polyether such as PEO with a suitable polymer supplied an effective way to improve the performance of CO2 separation membranes [1].The polar ether linkages can interact with CO2 via hydrogen bonding and increase its solubility in polymers.However,semi-crystalline PEO exhibits low CO2 permeability.Hence,the blending of polyethylene glycol dimethyl ether (PEG-DME) with polyvinylidene fluoride (PVDF) was proposed in this study to manufacture high performance CO2 separation membranes,in which methyl end groups prevented the interaction between polymer chains and increased the fractional free volume [2].The PVDF/PEG-DME blend selective layer was fabricated on a porous support layer of polypropylene by solvent evaporation method.The effects of PVDF and PEG-DME contents in the casting solution of DMAc,as well as the solvent evaporation temperature,were investigated for preparing an outstanding CO2 separation membrane.Single gas permeation tests were conducted under the transmembrane pressure of 0.4MPa,and it was demonstrated that the optimal PVDF and PEG-DME contents were 20% and 50% in mass,respectively,and the evaporation temperature was 30 °C.The surface of blend membrane exhibited morphology of distinct reticular structure under SEM analyses.As a result,the PVDF/PEG-DME blend membrane performed excellently with CO2/N2 selectivity up to 47.0 and CO2 permeation rate up to 84.7 GPU.