The Preparation Of PVC/ZnO Composite Membrane And Its Anti-protein Pollution Performance

The membrane separation process is a key component of seawater desalination,clean water production and the wastewater recovery,but various types of membrane fouling will largely reduce its water treatment efficiency and material lifespan and increase the production costs.In order to improve the anti-fouling and hydrophilicity of PVC membrane,the advantages of ZnO nanoparticles such as large specific surface area and good hydrophilicity were utilized in this paper.The modified ZnO nanocomposite particles were added into the PVC membrane matrix by a simple blending method,and the influence of the addition amount of the nanocomposite particles on the structure and anti-fouling properties of the membranes were investigated.It provides a simple method for modification of hydrophilic and anti-fouling properties of PVC membrane.In view of the shortcoming of easy agglomeration of nanoparticles,zinc oxide nanoparticles were modified by carboxymethylated chitosan(CMC)to improve the hydrophilicity and dispersibility.Then ZnO-CMC nanocomposite particles were added into the PVC casting solution by simple blending method.The results show that with the increase of ZnO-CMC nanocomposite particles content,the pore size and porosity of the PVC composite membranes were increased slightly.The hydrophilicity,water permeation flux and the anti-protein fouling performance also were increased.When the addition amount of nanocomposite paricles reached to 0.35 wt%,the composite membranes had the best hydrophilicity and anti-fouling properties.In addition,the antibacterial properties of pure PVC membrane and PVC composite membranes were tested respectively,and it was found that pure PVC membrane has no antibacterial properties,while the composite membranes added with ZnO-CMC nanocomposite particles have good antibacterial properties.Polyethyleneimine(PEI)is a polymer containing a quantity of amino groups.which can be substituted with PVC at 60?.Therefore,in this paper,ZnO nanoparticles were modified by PEI to prepare amino-functionalized ZnO nanoparticles,and then ZnO-PEI nanocomposite particles were blended into PVC membrane.The results show that the pore size and porosity of the composite membranes were increased slightly.These result in an increase in the permeability of the membranes.The hydrophilicity and the anti-fouling property were also improved greatly.When the addition amount of ZnO-PEI nanocomposite particles is 1.0 wt%of PVC content,the hydrophilicity and anti-fouling performance of PVC composite membranes was optimal.