کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5366680 | 1388352 | 2006 | 10 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Chemical alteration of poly(vinyl fluoride) Tedlar® induced by exposure to vacuum ultraviolet radiation
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی تئوریک و عملی
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چکیده انگلیسی
In this study the chemical alteration of poly(vinyl fluoride) Tedlar® by vacuum ultraviolet radiation (VUV) (115-400Â nm) has been examined using X-ray photoelectron spectroscopy (XPS). The initial F/C atom ratio of 0.34 decreases to 0.17 after a 2-h exposure. The F/C atom ratio is further reduced to a steady-state value of approximately 0.04 after a 24-h exposure. Similarly, the O/C atom ratio is reduced from 0.08 to 0.05 and then to 0.02 during these two exposures. As the F and O are removed by VUV exposure, the C concentration increases from 70.5 to 82.0 and then to 94.6Â at.% thus forming a graphitic or amorphous carbon-like layer which erodes more slowly than the virgin Tedlar surface. Exposure of the VUV-damaged surface to O2 results in chemisorption of O, indicating that reactive sites are formed during the chemical erosion by VUV. Further exposure to VUV removes this chemisorbed oxygen but a subsequent exposure to air at atmospheric conditions causes a three-fold increase in O chemisorbed at the surface. Comparison of XPS data indicates that the mechanisms of chemical alteration by VUV radiation and hyperthermal (â¼5Â eV) atomic oxygen (AO) are similar.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Applied Surface Science - Volume 252, Issue 10, 15 March 2006, Pages 3789-3798
Journal: Applied Surface Science - Volume 252, Issue 10, 15 March 2006, Pages 3789-3798
نویسندگان
Michael L. Everett, Gar B. Hoflund,