Protein immobilization onto poly (vinylidene fluoride) microporous membranes activated by the atmospheric pressure low temperature plasma

Hydrophobic poly (vinylidene fluoride) (PVDF) membrane surface was treated with atmospheric pressure low temperature plasma and investigated physical and chemical surface characterization. The contact angle of water on the exposed membrane surface was reduced with increasing of the treatment voltage and time, so indicates that the treatments can modify the PVDF membrane surface from hydrophobic to hydrophilic. In order to analyze the phenomenon in detail, the progress of defluorination including dehydrofluorination and oxidation reactions onto the surface was examined by X-ray photoelectron spectroscopy (XPS), and revealed the most effective treatment condition. The degree of grafting used acrylic acid monomer onto the surface has influenced with monomer concentration, reaction temperature and reaction time. Scanning electron microscopy (SEM) and atomic force microscopy (AFM) were employed to study the surface morphology. The membrane surfaces conjugated bovine serum albumin (BSA) as a protein were surely detected the nitrogen element contained with BSA.