TY - JOUR
T1 - On the correlation between the photoexcitation pathways and the critical energies required for ablation of poly(methyl methacrylate)
T2 - A molecular dynamics study
AU - Conforti, Patrick F.
AU - Prasad, Manish
AU - Garrison, Barbara J.
N1 - Funding Information:
This work was supported by the National Science Foundation through the Information Technology and Research Program, Grant No. 0426604. Computer support was provided by the Graduate Education and Research Services at Penn State University.
PY - 2008
Y1 - 2008
N2 - The energetics initiating ablation in poly(methyl methacrylate) (PMMA) are studied using molecular dynamics (MD) simulation. The critical energy to initiate ablation in PMMA following the absorption of photons is investigated for two penetration depths along a range of fluences using a coarse-grained, hybrid Monte Carlo-MD scheme. Both heating and direct bond scission are simulated separately after photon absorption with additional transformation of material occurring via chemical reactions following the photochemical bond cleavage. For a given type of absorption and reaction channel, a critical energy can well describe the amount of energy required to initiate ablation. The simulations show a decrease in the critical energy when a greater amount of photochemistry is introduced in the system. The simulations complement experimental studies and elucidate how enhanced photochemistry lowers ablation thresholds in polymer substrates.
AB - The energetics initiating ablation in poly(methyl methacrylate) (PMMA) are studied using molecular dynamics (MD) simulation. The critical energy to initiate ablation in PMMA following the absorption of photons is investigated for two penetration depths along a range of fluences using a coarse-grained, hybrid Monte Carlo-MD scheme. Both heating and direct bond scission are simulated separately after photon absorption with additional transformation of material occurring via chemical reactions following the photochemical bond cleavage. For a given type of absorption and reaction channel, a critical energy can well describe the amount of energy required to initiate ablation. The simulations show a decrease in the critical energy when a greater amount of photochemistry is introduced in the system. The simulations complement experimental studies and elucidate how enhanced photochemistry lowers ablation thresholds in polymer substrates.
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U2 - 10.1063/1.2921800
DO - 10.1063/1.2921800
M3 - Article
AN - SCOPUS:44649133265
SN - 0021-8979
VL - 103
JO - Journal of Applied Physics
JF - Journal of Applied Physics
IS - 10
M1 - 103114
ER -