A new kind of mixed matrix membranes (MMMs) with cellulose acetate butyrate (CAB) as matrix and multi-walled carbon nanotubes (MWCNTs) as fillers was prepared by solvent mixing-solution casting method.The morphology

structure and mechanical properties of CAB/MWCNTs MMMs were characterized using scanning electron microscopy (SEM)

transmission electron microscopy (TEM) and tensile testing.The results showed that MWCNTs and CAB matrix had good interfacial adhesion.No obvious defect was observed on the fracture surface of CAB/MWCNTs MMMs.The obtained CAB/MWCNTs MMMs exhibited good mechanical properties.Furthermore

gas separation properties of the CAB/MWCNTs MMMs for O2

N2

CH4

CO and CO2 were investigated.It was found that

with the increase of MWCNTs content

the permeability coefficients of CAB/MWCNTs MMMs for all test gases (O2

N2

CH4

CO

CO2) were significantly improved

especially for quicker gasO2 and CO2.When the content of MWCNTs was 30 wt%

the permeability of MMMs for O2 and CO2 reached 40.24 and 180.20 Barrer

which compared with neat CAB membrane

increased by 300% and 260%

respectively.Moreover

the CAB/MWCNTs MMMs showed excellent separation property for some gas pairs

such as CO2/N2

CO2/CH4

CO2/CO and O2/N2.The selectivity of CO2/N2

CO2/CH4 and CO2/CO was not sacrificed with the increase of CO2 permeability.More interestingly

with the increase of O2 permeability

the selectivity of O2/N2 also increased from 3.2 to 4.0

an increase of 25% compared with neat CAB membranes.Therefore

the present work provides a facile and effective method to prepare new kind of cellulose based MMMs with improved gas separation properties.