Two-dimensional metal-organic framework(2D MOF)nanosheets show great potential in the field of separation science due to their unique structure and properties.Post-synthetic modification(PSM)can effectively regulate the functions of MOFs on the premise of keeping their crystal structures unchanged.This paper aims to develop a novel 2D MOF nanocomposite membra

ne for efficient oxygen separation from water based on the PSM strategy.A copper(Ⅱ)-2-amino-1

4-benzenedicar-boxylate/polyurethane(CuBDC-NH

2

/PU)nanocomposite membrane is successfully constructed by compouding aminated CuBDC-NH

2

nanosheets with isocyanate-terminated PU oligomers.The research results demonstrate that when the mass fraction of CuBDC-NH

2

loading is 4%

the oxygen/water vapor separation selectivity of the composite membrane is significantly enhanced.The oxygen permeability rate increases from 1.872×10

5

cm

3

/(m

2

·24h·0.1MPa) for the pure PU membrane to 2.275×10

6

cm

3

/(m

2

·24h·0.1MPa)

while the water vapor transmission rate only increases slightly from 763.57cm

3

/(m

2

·24h·0.1MPa)to 930.87cm

3

/(m

2

·24h·0.1MPa).The separation selectivity of oxygen to water vapor is improved by nearly 10 times

indicating its efficient performance for oxygen separation from water.