Department of Chemistry and Biochemistry, Montana State University, Bozeman, Montana 59717, USA.
ACS Appl Mater Interfaces. 2009 Jan;1(1):187-96. doi: 10.1021/am800015k.
Beam-surface scattering experiments were used to probe products that scattered from FEP Teflon surfaces during bombardment by various combinations of atomic and molecular oxygen, Ar atoms, and vacuum ultraviolet (VUV) light. A laser-breakdown source was used to create hyperthermal (translational energies in the range 4-13 eV) beams of argon and atomic/molecular oxygen. The average incidence energy of these beams was tunable and was controlled precisely with a synchronized chopper wheel. A filtered deuterium lamp provided a source of VUV light in a narrow-wavelength range centered at 161 nm. Volatile products that exited the surfaces were monitored with a rotatable mass spectrometer detector. Hyperthermal O atoms with average translational energies above approximately 4 eV may react directly with a pristine FEP Teflon surface, and the reactivity appears to increase with the translational energy of the incident O atoms. VUV light or highly energetic collisions of O2 or Ar may break chemical bonds and lead to the ejection of volatile products; the ejection of volatile products is enhanced when the surface is subjected to VUV light and energetic collisions simultaneously. Exposure to VUV light or to hyperthermal O2 or Ar may increase the reactivity of an FEP Teflon surface to O atoms.
束流-表面散射实验被用来探测在各种原子和分子氧、氩原子和真空紫外（VUV）光的组合轰击下从 FEP 特氟龙表面散射的产物。激光击穿源被用来产生超热（在 4-13 eV 的范围内的平移能量）的氩和原子/分子氧束。这些束的平均入射能是可调的，并通过同步斩波器精确控制。过滤后的氘灯提供了一个位于 161nm 左右的窄波长范围内的 VUV 光源。挥发性产物从表面逸出，用可旋转的质谱仪探测器进行监测。平均平移能高于约 4 eV 的超热 O 原子可能会与原始的 FEP 特氟龙表面直接反应，反应性似乎随入射 O 原子的平移能增加而增加。VUV 光或 O2 或 Ar 的高能碰撞可能会打破化学键，并导致挥发性产物的喷射；当表面同时受到 VUV 光和高能碰撞的作用时，挥发性产物的喷射会增强。暴露于 VUV 光或超热 O2 或 Ar 可能会增加 FEP 特氟龙表面对 O 原子的反应性。
