| Summary: | 碩士 === 國立臺灣科技大學 === 化學工程系 === 98 === Oxygen plasma and polydopamine coating were performed on two polymers with excellent mechanical strength and good biocompatibility, polyvinilydene fluoride and polysulfone, to study the effects of surface modifications on the surface physical-chemical properties and on the cell adhesion behaviors.
O2 plasma altered both PVDF and PSf to more hydrophilic where the WCA reduced more significantly on the O2 plasma treated PSf. By using XPS, the presence of oxygen functionalities on modified surfaces were confirmed and further deconvolution revealed the presence of C-O, C=O, and O-C=O groups. Surface etching occurred on both O2 plasma modified polymers as demonstrated by AFM analysis. On the other hand, the polydopamine coating resulted in similar reduction of WCA and surface composition on both PVDF and PSf which was also confirmed by AFM.
The biocompatibility was evaluated by directly cultivating L-929 mouse fibroblast cells on pristine and modified PVDF and PSf. For PVDF, the highest cell density, three to four folds than the pristine, was achieved by either O2 plasma modification or polydopamine coating. On the other, for PSf, the polydopamine coating resulted in higher cell density compared with O2 plasma treatment.
PVDF is widely used for filtration owing to its good mechanical property, thermal stability, and good solvent resistance. The commonly recognized problem of PVDF filtration membrane was the fouling due to the adsorbed protein on the hydrophobic membrane surface which reduced the permeate flux. In this study, the second goal was to reduce protein fouling on Durapore® membrane by surface modification with O2 plasma treatment and polydopamine coating.
Both O2 plasma modified and polydopamine coated Durapore® membrane showed reduced WCA where O2 plasma treatment resulted in higher surface area due to plasma etching and higher surface electronegativity, the polydoapmine coating reduced membrane surface area and imparted positively-charged functionalities on membrane surface.
The BSA fouling resistance was created by O2 plasma on Durapore® membrane where the fouling time was delayed by more than 10 min and the flux was higher than the pristine Durapore® membrane. Further reduction of membrane fouling was attained by prolonging plasma treatment time which resulted in more negatively charged surface. On the other hand, the polydopamine coated Durapore® membrane showed rapid flux reduction and no particular anti-fouling property was observed. By performing the dynamic BSA adsorption experiment, it allowed to draw a conclusion that the membrane fouling was strongly affected by the overall resulted properties of surface electrical charge, surface wettability and surface area.
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