| Summary: | 碩士 === 中原大學 === 土木工程研究所 === 99 === The antibacterial compounds extracted from Chinese herbs and natural plants revealed no side effects, no environmental hazard on human beings. More and more research are processed recently to study the antibiotic effect of Chinese herbs extracts. In this study, polypropylene (PP) non-woven filter was modified by an oxygen-based RF plasma and was coated by the extract of Saposhnikovia Divaricate to evaluate the inhibition efficiency of bioaerosols.
The coating rate will be elevated as increasing applied power and extended modification time. When PP was modified at the conditions: 5 sccm of O2, 0.09 torr of pressure, 40 W of power, and 30 seconds of modification, the coating rate of Divaricate Saposhnikovia root extract increased from 8.2% for unmodified PP to 18.9% for modified PP.
Higher coating rate will lead to higher antibacterial effects. The coating rate is 27% and the inhibition efficiency of Staphylococcus aureus reaches 75% after three times desorption by ultrasonic shaking. The inhibition efficiency of Staphylococcus aureus reduced to 61% while the coating rate decreased to 10.3%.
The results of the pilot test showed that after a longer filtration time, the antibacterial efficiency could be almost 100% by elevating the still duration. The filtration efficiency of E coli was 44% for modified PP (under 40 W, 30 sec, 22.9% of coating rate), higher than 33% for unmodified PP. The persistent inhibition efficiency of E.coli on modified PP for 30 min still duration after 5 min filtration was near 100%. After 30 min filtration, the inhibition efficiency of E.coli on modified PP was 67% for 480 min still duration, higher than that for 0 min still duration (33%). However, the inhibition efficiency of Bacillus subtilis spores was similar between modified and unmodified PP owing to PP’s static electricity on unmodified PP leading to higher filtration efficiency than modified PP. The inhibition efficiency of acillus subtilis spores on modified PP for 120 min still duration after 30 min filtration was above 97%.
This study proved that not only the coating rate of Divaricate Saposhnikovia root extract was improved, but also the inhibition efficiency of bioaerosols was elevated by modifying PP in an oxygen-based RF plasma environment. More, the test result of Divaricate Saposhnikovia root extract coated PP further implied its potential application on indoor air quality improvement.
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