Preparation And Performance Study Of Pebax/hollow Nanosphere Mixed Matrix Membrane

The burning of fossil fuels leads to a large number of emissions of CO₂and other greenhouse gases,causing the greenhouse effect and environmental degradation.Therefore,the development of capture and separation technology for CO₂and other greenhouse gases is the current focus.Membrane separation technology stands out from many CO₂separation technologies because of its advantages of high efficiency,energy saving and environmental protection.Membrane material is the core of membrane separation technology.The development of CO₂membrane material with excellent performance is the key of gas membrane separation technology.Pebax has strong affinity for CO₂and a strong separation effect for CO₂/N₂and CO₂/CH₄,making it a CO₂separation membrane material with great application potential.In order to increase the permeability,the polymer was prepared into the hollow nanoparticle and filled into the polymer matrix to prepare the mixed matrix membrane,which can reduce the mass transfer path of the gas in the membrane,and then reduce the mass transfer resistance,the gas permeation and separation performance were improved.The main contents of this paper are as follows.Firstly,the hollow polypyrrole nanosphere with porous shell was synthesized by chemical polymerization with pyrrole as monomer and nanometer silica as template.The diameter of the microsphere was about 30 nm,and the drameter of holes in the shell was 2.17 nm.The mixed matrix membrane of Pebax/hollow polypyrrole nanosphere was prepared by adding hollow polypyrrole nanospheres into Pebax as filler,and the effect of nanosphere addition on gas permeability separation performance was investigated.The results showed that under the operating conditions of 0.2 MPa and 35?,when the addition amount of hollow polypyrrole nanospheres was 1 wt.%,the permeability of CO₂in the mixed matrix membrane was 274 Barrer,the selectivity of CO₂/N₂was 40.1,and that of CO₂/CH₄was 12.8.Then,the composite membrane of Pebax/hollow polypyrrole nanospheres/PEI was prepared with Pebax/hollow polypyrrole nanospheres as the coating solution and PEI as the supporting layer.The effects of solvent ratio,polymer concentration,impregnation time,base membrane state and lift speed on the permeance of the composite membrane were investigated.The results showed that under the wet membrane condition of surface crosslinking treatment of PEI basement membrane,the composite membrane prepared under the conditions of solvent ratio of 9:1,polymer concentration of 3 wt.%,impregnation time of 120 s,and lift speed of 2 m/s,the permeance reached 53.2 GPU,and the CO₂/N₂separation coefficient was 44.2.