Improvement of filtration and antifouling performance of cellulose acetate membrane reinforced by dopamine modified cellulose nanocrystals

A thin layer of polydopamine (PDA) was coated on the surface of cellulose nanocrystals (CNCs) by the self-polymerization of dopamine (DA) in water to improve the hydrophilicity and lipophilicity of CNCs. Then, the CNCs coated with PDA ([email protected]) were blended with pore forming agent and cellulose acetate (CA), and the CA composite membrane reinforced by [email protected] ([email protected]/CA) was prepared by solution phase transformation method. The effects of [email protected] content on the filtration performance, antifouling ability and mechanical properties of the composite membrane were studied. The results show that adding a small amount of [email protected] can significantly improve the filtration capacity, antifouling performance and tensile strength of CA membrane. When the content of [email protected] was 4 wt%, the hydraulic permeability, flux recovery ratio and tensile strength of [email protected]/CA composite membrane increased by 33%, 15% and 76%, respectively. Simple DA modification improves the lipophilicity and dispersion of CNCs, enhances the binding force between CNCs filler and CA matrix, and improves the performance of CA composite membrane, thus widen the industrial application of CA materials, and shows a broad application prospect in the field of biological separation membrane and water treatment membrane.