Characterization of polysulfone based hemodialysis membranes by afm

摘要

Most of the hemodialysis membrane materials are hydrophobic in nature and allow protein adsorption on the surface easily due to hydrophobic interaction between membrane surface and protein molecules when in contact with blood. Adsorbed proteins can affect platelet and leukocyte adhesion, and modulate the response of plasmatic reactions followed by the activation of different defense systems in blood (Sun et al. 2003). In order to solve this problem, surface modification techniques such as; blending hydrophilic polymers into the membrane forming solution, grafting hydrophilic groups by UV-irradiation or low temperature plasma technique, graft copolymerization of monomers, coating with hydrophilic polymers or copolymers (Sun et al. 2003) and polyelectrolyte multilayer immobilization (Yu et al. 2007), are commonly used. Recently, the layer by layer self-assembly (LBL) technique has emerged as an efficient and easy surface modification technique in biomedical engineering. The method basically depends on the sequential deposition of polycations and polyanions on a polymeric surface upon immersing the membrane into an aqueous solution of oppositely charged polyelectrolyte solutions (Yu et al. 2007).