The study of application of polyamide membrane modified with polydopamine

Membrane separation processes play a very important role in the separation industry. Microfiltration, ultrafiltration, nanofiltration, reverse osmosis (RO) are widely used membrane separation processes, and their difference is based on separation mechanisms and size of the separated particles [1]. For example, polyamide membrane used for the separation of pharmaceutical compounds from aqueous streams [2]. In the present study, a commercial polyamide membrane was modified via surface coating of polydopamine (PDA). It is well-known that a tightly adherent PDA layer can be generated over a wide range of material surfaces through a simple dip-coating process in dopamine aqueous solution [3]. PDA modified polyamide membranes can be made according to the requirements for the separation of organic matter by the addition of supplementary materials. The resulting PDA coating is prone to condensation of the organic compound because of its robust reactivity. In the condensation of L-cysteine on the PDA modified polyamide membrane, the interaction effects of L-cysteine and polydopamine occur. The condensation of L-cysteine was recorded by spectroscopic and spectrophotometer curves and membrane surface properties were characterized through scanning electron microscopy (SEM). The results showed that modification enhanced the surface hydrophilicity and condensation of L-cysteine.