Kinematics and dynamics of atomic-beam scattering on liquid and self-assembled monolayer surfaces

Abstract

We have conducted investigations of the energy transfer dynamics of atomic oxygen and argon scattering from hydrocarbon and fluorocarbon surfaces. In light of these results, we appraise the applicability and value of a kinematic scattering model, which views a gas-surface interaction as a gas-phase-like collision between an incident atom or molecule and a localized region of the surface with an effective mass. We have applied this model to interpret the effective surface mass and energy transfer when atoms strike two different surfaces under identical bombardment conditions. To this end, we have collected new data, and we have re-examined existing data sets from both molecular-beam experiments and molecular dynamics simulations. We seek to identify trends that could lead to a robust general understanding of energy transfer processes induced by collisions of gas-phase species with liquid and semi-solid surfaces.

Predictive simulation of non-steady-state transport of gases through rubbery polymer membranes

“…37 At incident energies of 8 kJ/mol, twice the average kinetic energy for gas molecules in this study, the oxygen molecules fully transfer their excess energy to the hydrocarbon surface, 37 indicating a sticking probability near 100%. A MD study of Ar colliding with hydrocarbon self-assembled monolayers 38 show that the hydrocarbon chains are able to redistribute the energy of the incoming molecule on the same timescale as the impact of the atom with the surface by recruiting a large number of low-frequency vibrational modes. 38 PDMS similarly contains a large number of low-frequency interactions, and so a similar energy transfer mechanism may apply.…”

“…A MD study of Ar colliding with hydrocarbon self-assembled monolayers 38 show that the hydrocarbon chains are able to redistribute the energy of the incoming molecule on the same timescale as the impact of the atom with the surface by recruiting a large number of low-frequency vibrational modes. 38 PDMS similarly contains a large number of low-frequency interactions, and so a similar energy transfer mechanism may apply. Thus, we conclude that a sticking probability of 30% to 50% is reasonable for a light, inert gas molecule at ambient temperature colliding with a flexible polymer surface, though further study on this type of system would be useful.…”

Mechanistic details of energy transfer and soft landing in ala2-H+ collisions with a F-SAM surface

“…10,11 For low collision energies the ion may adsorb on the surface intact, with or without charge retention, a process referred to as SL. [28][29][30][31][32][33][34][35][36][37][38][39][40][41]45 Energy transfer probabilities to the surface and projectile may be determined, [28][29][30][31][32][33][34][35][36][37][38][39][40][41]45 as well as features of the collision such as the importance of surface penetration 29,[33][34][35][36]41,46,47 or physisorption. 13 SL and RL have numerous uses, [12][13][14][15][23][24][25]42 including preparation of protein or peptide a...…”

Ionic Liquid–Vacuum Interfaces Probed by Reactive Atom Scattering: Influence of Alkyl Chain Length and Anion Volume

“…distributions for OH and H 2 O scattering from [C 8 mim][BF4 ] are shown in The data collected in these experiments appeared to be bimodal, and the two features were interpreted in terms of two limiting cases for scattering, as has been done previously 9. 39,53-54 At short flight times, the dominant component of the TOF distributions is the result of impulsive scattering (IS).…”