کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5364702 | 1388319 | 2007 | 4 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Computational investigation into the mechanisms of UV ablation of poly(methyl methacrylate) Computational investigation into the mechanisms of UV ablation of poly(methyl methacrylate)](/preview/png/5364702.png)
Molecular dynamics simulations with an embedded Monte Carlo based reaction scheme were used to study UV ablation of poly(methyl methacrylate) (PMMA) at 157Â nm. We discuss the onset of ablation, the formation and distribution of products in the plume and stress relaxation of the polymer matrix. Laser induced heating and bond-breaks are considered as ablation pathways. We show here that depending on the nature of energy deposition the evolution of ablation plume and yield composition can be quite different. If all of photon energy is converted to heat it can set off ablation via mechanical failure of the material in the heated region. Alternatively, if the photon energy goes towards breaking bonds first, it initiates chemical reactions, polymer unzipping and formation of gaseous products inside the substrate. The ejection of these molecules has a hollowing out effect on the substrate which can lead to ejection of larger chunks. No excessive pressure buildup due to creation of gaseous molecules or entrainment of larger polymer chunks is observed in this case.
Journal: Applied Surface Science - Volume 253, Issue 15, 30 May 2007, Pages 6382-6385