Inner Surface Modification of Polysulfone Hollow Fiber Membrane through Polydopamine Coating Treatment

Hypothesis:

Hemodialysis is a procedure in which a dialyzer is used to clean the blood from waste products such as urea. Man-made membranes are often used to make hemodialysis dialyzers. Most of the employed polymers are not well compatible with blood. Coating method with hydrophilic polymers is a very simple and effective method that is used to improve the hydrophilic and biocompatible properties of produced membranes. Polydopamine is one of the hydrophilic polymers that has been considered for its high hydrophilic properties and good adhesion to cover membranes.

The coating of the inner surface of hollow fiber membranes was applied for the first time. The polysulfone membrane was coated with polydopamine solution, injected at specified time and pressure. The structural and permeability properties of the membrane treated by this technique were compared with the untreated membrane and the membrane whose outer surface was coated with polydopamine solution.

 No statistically significant change in hydraulic permeability and pore size of hollow fiber membranes was observed after treatment at 95% confidence level. Also, studies were performed by scanning electron microscopy and X-ray energy diffraction spectroscopy techniques on the cross-sectional area of hollow fibers before and after treatments. The results of X-ray energy diffraction spectroscopy technique showed that the amount of elemental oxygen on the inner surface of hollow fibers that were internally coated with polydopamine has significantly increased. The mechanical properties of hollow fiber membranes were also evaluated. The statistical analysis of the treated and untreated membranes showed that the strength of the membrane treated by injection technique in comparison with untreated and external surface treated membranes has significantly increased at 95% confidence level.