Modification of braid-reinforced cellulose acetate hollow fiber membrane by doping graphene oxide

摘要

To improve the permeability, antifouling and mechanical performance of cellulose acetate (CA) hollow fiber membrane is the objective of this study. Braid-reinforced method, where a simple coating process is implemented with high-strength hollow tubular braid as the reinforcement, is adopted to prepare the reinforced CA hollow fiber membrane; and graphene oxides (GOs) with various sheet size and additive content are incorporated into the separation layer to optimize the permeability and antifouling performance of the membrane. Scanning electron microscopy (SEM) images show that the prepared membranes have a favorable interfacial bonding state between the separation layer and the braid; the more and longer finger-like macro-void and thinner skin layer appear in the separation layer after GOs modification. The pure water flux of membrane increases from 129.8 L/m(2)h to 158.1 L/m(2)h by introducing 1 wt% GO (with sheet size of 30-50 mu m). Besides, the GOs modification brings about increased protein solution permeate flux and flux recovery during the protein solution filtration. The tensile strength (about 30 MPa) of the braid-reinforced membranes mainly depends on the braid, which is much higher than the conventional solution spinning hollow fiber membrane. Meanwhile, there is a decent boost in the bursting strength of the membrane by GOs modification.