| Summary: | 碩士 === 大同大學 === 材料工程學系(所) === 94 === Expanded polytetrafluororthylene (ePTFE) film is a kind of surface hydrophobic materials. The titania coating can improve the surface antibacterial and absorptive bacterium properties. The commercial method for titania coating is spin coatings. Since the hydrophobic surface of ePTFE film makes the spin coating infeasible, the plasma polymerization of HMDSZ and subsequent plasma oxygen treatment is required to enhance hydrophilic properties. It was found that hydrophilic groups, e.g. hydroxyl and silicone-oxide species, can be formed on the surface-modified by plasma treatment. The water contact angle was substantially decreased from 125° to 8°. In term of water contact angle , the optimal treatment is HMDSZ plasma(10W/10min/50mtorr) and Oxygen plasma (50W/10min/200mtorr). On the plasma-treated surface, the TiOx-containing film was spin-coated (1200 rpm, 25s) from sol-gel solution. Conventionally the as-spinned film was annealed to reduce the organic residues. However, the high temperature treatment is not appropriate for the thermal-sensitive organic materials, such as ePTFE. In this study, the post plasma oxidation was attempted to reduce the organic residues of the TiOx-containing film on ePTFE. In term of water contact angle, the optimal treatment is Oxygen plasma (75W/45min/200mtorr). After plasma oxygen oxidation, the relative intensity of methyl group to the Ti-C, Ti-O and TiO2 groups was found to increase from the chemical analyses. After immobilization, the presence of P atom and O-P-O on surface indicates the phosphate ion is successfully immobilized by UV irradiation. The antibacterium test shows that the amount of bacteria was decreased after TiOx coating with oxygen plasma treated. To enhance the antibiotic behavior, the surface phorylation can facilitate the absorption of bacteria to “trap” the bacteria in dark. The synergetic effect of trapping of bacteria on phorylated sites and the intrinsic antibiotic properties of titania can further enhance the antibiotic effect on the ePTFE. The surface phorylation would gradually reduce the population of bacteria after 20min ~30 min UV irradiation in antibiotic test. The reproductivity of the antibacterium properties seems to be fairly good in this method.
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