Surface grafting bactericidal materials are commonly used methods to improve the antibacterial and anti-pollution properties of membranes. Guanidine compounds have received a lot of attentions due to their efficient and broad-spectrum antibacterial properties

easy preparation and low toxicity to the mammalian cell. Herein

a guanidine based polymer

namely PEIGH

was prepared through melt phase polycondensation of polyethyleneimine and guanidine hydrochloride

then used for ultrafiltration membrane surface modification with the assist of polydopamine. The results show that the synthesized PEIGH possesses good antibacterial property. Compared to the unmodified membranes

the membranes modified by PEIGH have better wettability. The permeation flux increases by 11%-98% and rejection for bovine serum albumin raises from 96.6% to 98.3% above. Antibacterial

anti-organic and anti-biobial properties have been significantly improved.