2.1 Materials
The Polyethersulfone (PES) porous membrane with a mean pore size of 0.45 μm, porosity of 0.7 and thickness of 100-150 μm is provided by Chuangwei Filter Materials Company. Cupric(II) nitrate trihydrate (Cu(NO3)2·3(H2O), Methyl Blue (MB), Congo Red (CR), ethanol and methanol are purchased from Kelong Chemical Company. N,N,N,N-tetramethyl-1,6-hexanediamine and 1, 3, 5-benzenetricarboxylic acid are purchased from Aladdin. All the reagents are analytical grade purity used as received without further treatment.