Graphene oxide (GO) can be quickly deposited on a positively charged porous matrix via a layer-by-layer self-assembly strategy because GO nanosheets contain rich negatively charged

oxygen-containing function groups

such as COOH. In this paper

the GO-ceramics composite nanofiltration membrane was prepared via layer-by-layer deposition of GO solution and eolyethyleneimine (PEI) solution alternately

and then cross-linked by epoxy chloropropane (ECH) on 3-aminopropyltriethoxysilane-modified porous Al2O3 supports. The optimum preparation conditions were: PEI 5g·L-1

pH=9; NaCl 0.3 mol·L-1; GO 0.6 mg·L-1

pH 4.5; ECH 6.25 ml·L-1 and heat treatment 50℃/70 min. Under the conditions of 0.6 MPa

when the self-assembly layer number increased from 1 to 4

the rejection to 2 g·L-1 MgCl2 were 90.16%

93.71%

97.54%

and 92.93% respectively

and the flux of self-assembled monolayer membrane was 21.92 L·m-2·h-1. The rejection orders of inorganic salts of GO-ceramics composite nanofiltration membrane were as follows: MgCl2 >MgSO4 >NaCl >Na2SO4

therefore they showed the typical positively charged nanofiltration membrane characteristics.