Dynamics of molecular impacts on soft materials: From fullerenes to organic nanodrops

A. Delcorte, Barbara Jane Garrison, K. Hamraoui

Research output: Contribution to journalArticle

71 Citations (Scopus)

Abstract

The present theoretical study explores the interaction of various energetic molecular projectiles and clusters with a model polymeric surface, with direct implications for surface analysis by mass spectrometry. The projectile sizes (up to 23 kDa) are intermediate between the polyatomic ions (SF5, C 60) used in secondary ion mass spectrometry and the large organic microdroplets generated, for example, in desorption electrospray ionization. The target is a model of amorphous polyethylene, already used in a previous study [Delcorte, A.; Garrison, B. J. J. Phys. Chem. C 2007, 111, 15312]. The chosen method relies on classical molecular dynamics (MD) simulations, using a coarsegrained description of polymeric samples for high energy or long time calculations (20-50 ps) and a full atomistic description for low energy or short time calculations (<1 ps). Two regions of sputtering or desorption are observed depending on the projectile energy per nucleon (i.e., effectively the velocity). The transition, occurring around 1 eV/nucleon, is identi-fied by a change of slope in the curve of the sputtering yield per nucleon vs energy per nucleon. Beyond 1 eV/ nucleon, the sputtering yield depends only on the total projectile energy and not on the projectile nuclearity. Below 1 eV/nucleon, i.e., around the sputtering threshold for small projectiles, yields are influenced by both the projectile energy and nuclearity. Deposition of intact molecular clusters is also observed at the lowest energies per nucleon. The transition in the sputtering curve is connected to a change of energy deposition mechanisms, from atomistic and mesoscopic processes to hydrodynamic flow. It also corresponds to a change in terms of fragmentation. Below 1 eV/nucleon, the projectiles are not able to induce bond scissions in the sample. This region of molecular emission with minimal fragmentation offers new analytical perspectives, out of reach of smaller molecular clusters such as fullerenes.

Original languageEnglish (US)
Pages (from-to)6676-6686
Number of pages11
JournalAnalytical chemistry
Volume81
Issue number16
DOIs
StatePublished - Aug 15 2009

Fingerprint

Fullerenes
Projectiles
Sputtering
Desorption
Electrospray ionization
Surface analysis
Polyethylene
Secondary ion mass spectrometry
Mass spectrometry
Molecular dynamics
Hydrodynamics
Ions
Computer simulation

All Science Journal Classification (ASJC) codes

  • Analytical Chemistry

Cite this

Delcorte, A. ; Garrison, Barbara Jane ; Hamraoui, K. / Dynamics of molecular impacts on soft materials : From fullerenes to organic nanodrops. In: Analytical chemistry. 2009 ; Vol. 81, No. 16. pp. 6676-6686.
@article{e44d3c9d5f214f018467b22ac29d72bb,
title = "Dynamics of molecular impacts on soft materials: From fullerenes to organic nanodrops",
abstract = "The present theoretical study explores the interaction of various energetic molecular projectiles and clusters with a model polymeric surface, with direct implications for surface analysis by mass spectrometry. The projectile sizes (up to 23 kDa) are intermediate between the polyatomic ions (SF5, C 60) used in secondary ion mass spectrometry and the large organic microdroplets generated, for example, in desorption electrospray ionization. The target is a model of amorphous polyethylene, already used in a previous study [Delcorte, A.; Garrison, B. J. J. Phys. Chem. C 2007, 111, 15312]. The chosen method relies on classical molecular dynamics (MD) simulations, using a coarsegrained description of polymeric samples for high energy or long time calculations (20-50 ps) and a full atomistic description for low energy or short time calculations (<1 ps). Two regions of sputtering or desorption are observed depending on the projectile energy per nucleon (i.e., effectively the velocity). The transition, occurring around 1 eV/nucleon, is identi-fied by a change of slope in the curve of the sputtering yield per nucleon vs energy per nucleon. Beyond 1 eV/ nucleon, the sputtering yield depends only on the total projectile energy and not on the projectile nuclearity. Below 1 eV/nucleon, i.e., around the sputtering threshold for small projectiles, yields are influenced by both the projectile energy and nuclearity. Deposition of intact molecular clusters is also observed at the lowest energies per nucleon. The transition in the sputtering curve is connected to a change of energy deposition mechanisms, from atomistic and mesoscopic processes to hydrodynamic flow. It also corresponds to a change in terms of fragmentation. Below 1 eV/nucleon, the projectiles are not able to induce bond scissions in the sample. This region of molecular emission with minimal fragmentation offers new analytical perspectives, out of reach of smaller molecular clusters such as fullerenes.",
author = "A. Delcorte and Garrison, {Barbara Jane} and K. Hamraoui",
year = "2009",
month = "8",
day = "15",
doi = "10.1021/ac900746x",
language = "English (US)",
volume = "81",
pages = "6676--6686",
journal = "Analytical Chemistry",
issn = "0003-2700",
publisher = "American Chemical Society",
number = "16",

}

Dynamics of molecular impacts on soft materials : From fullerenes to organic nanodrops. / Delcorte, A.; Garrison, Barbara Jane; Hamraoui, K.

In: Analytical chemistry, Vol. 81, No. 16, 15.08.2009, p. 6676-6686.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Dynamics of molecular impacts on soft materials

T2 - From fullerenes to organic nanodrops

AU - Delcorte, A.

AU - Garrison, Barbara Jane

AU - Hamraoui, K.

PY - 2009/8/15

Y1 - 2009/8/15

N2 - The present theoretical study explores the interaction of various energetic molecular projectiles and clusters with a model polymeric surface, with direct implications for surface analysis by mass spectrometry. The projectile sizes (up to 23 kDa) are intermediate between the polyatomic ions (SF5, C 60) used in secondary ion mass spectrometry and the large organic microdroplets generated, for example, in desorption electrospray ionization. The target is a model of amorphous polyethylene, already used in a previous study [Delcorte, A.; Garrison, B. J. J. Phys. Chem. C 2007, 111, 15312]. The chosen method relies on classical molecular dynamics (MD) simulations, using a coarsegrained description of polymeric samples for high energy or long time calculations (20-50 ps) and a full atomistic description for low energy or short time calculations (<1 ps). Two regions of sputtering or desorption are observed depending on the projectile energy per nucleon (i.e., effectively the velocity). The transition, occurring around 1 eV/nucleon, is identi-fied by a change of slope in the curve of the sputtering yield per nucleon vs energy per nucleon. Beyond 1 eV/ nucleon, the sputtering yield depends only on the total projectile energy and not on the projectile nuclearity. Below 1 eV/nucleon, i.e., around the sputtering threshold for small projectiles, yields are influenced by both the projectile energy and nuclearity. Deposition of intact molecular clusters is also observed at the lowest energies per nucleon. The transition in the sputtering curve is connected to a change of energy deposition mechanisms, from atomistic and mesoscopic processes to hydrodynamic flow. It also corresponds to a change in terms of fragmentation. Below 1 eV/nucleon, the projectiles are not able to induce bond scissions in the sample. This region of molecular emission with minimal fragmentation offers new analytical perspectives, out of reach of smaller molecular clusters such as fullerenes.

AB - The present theoretical study explores the interaction of various energetic molecular projectiles and clusters with a model polymeric surface, with direct implications for surface analysis by mass spectrometry. The projectile sizes (up to 23 kDa) are intermediate between the polyatomic ions (SF5, C 60) used in secondary ion mass spectrometry and the large organic microdroplets generated, for example, in desorption electrospray ionization. The target is a model of amorphous polyethylene, already used in a previous study [Delcorte, A.; Garrison, B. J. J. Phys. Chem. C 2007, 111, 15312]. The chosen method relies on classical molecular dynamics (MD) simulations, using a coarsegrained description of polymeric samples for high energy or long time calculations (20-50 ps) and a full atomistic description for low energy or short time calculations (<1 ps). Two regions of sputtering or desorption are observed depending on the projectile energy per nucleon (i.e., effectively the velocity). The transition, occurring around 1 eV/nucleon, is identi-fied by a change of slope in the curve of the sputtering yield per nucleon vs energy per nucleon. Beyond 1 eV/ nucleon, the sputtering yield depends only on the total projectile energy and not on the projectile nuclearity. Below 1 eV/nucleon, i.e., around the sputtering threshold for small projectiles, yields are influenced by both the projectile energy and nuclearity. Deposition of intact molecular clusters is also observed at the lowest energies per nucleon. The transition in the sputtering curve is connected to a change of energy deposition mechanisms, from atomistic and mesoscopic processes to hydrodynamic flow. It also corresponds to a change in terms of fragmentation. Below 1 eV/nucleon, the projectiles are not able to induce bond scissions in the sample. This region of molecular emission with minimal fragmentation offers new analytical perspectives, out of reach of smaller molecular clusters such as fullerenes.

UR - http://www.scopus.com/inward/record.url?scp=68849097091&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=68849097091&partnerID=8YFLogxK

U2 - 10.1021/ac900746x

DO - 10.1021/ac900746x

M3 - Article

C2 - 20337378

AN - SCOPUS:68849097091

VL - 81

SP - 6676

EP - 6686

JO - Analytical Chemistry

JF - Analytical Chemistry

SN - 0003-2700

IS - 16

ER -