Interfacial Chemistry of Poly(methyl methacrylate) Arising from Exposure to Vacuum-Ultraviolet Light and Atomic Oxygen

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• 作者：Hanqiu Yuan ; Daniel R. Killelea ; Sanja Tepavcevic ; Scott I. Kelber ; S. J. Sibener
• 刊名：Journal of Physical Chemistry A
• 出版年：2011
• 出版时间：April 28, 2011
• 年：2011
• 卷：115
• 期：16
• 页码：3736-3745
• 全文大小：1023K
• 年卷期：v.115,no.16(April 28, 2011)
• ISSN：1520-5215

文摘

We herein report on the chemical and physical changes that occur in thin films of poly(methyl methacrylate), PMMA, induced by exposure to high-energy vacuum ultraviolet radiation and a supersonic beam of neutral, ground electronic state O(³P) atomic oxygen. A combination of in situ quartz crystal microbalance and in situ Fourier-transform infrared reflection鈭抋bsorption spectroscopy were used to determine the photochemical reaction kinetics and mechanisms during irradiation. The surface morphological changes were measured with atomic force microscopy. The results showed there was no enhancement in the mass loss rate during simultaneous exposure of vacuum ultraviolet (VUV) radiation and atomic oxygen. Rather, the rate of mass loss was impeded when the polymer film was exposed to both reagents. This study elucidates the kinetics of photochemical and oxidative reaction for PMMA, and shows that the synergistic effect involving VUV irradiation and exposure to ground state atomic oxygen depends substantially on the relative fluxes of these reagents.