Abstract
A coarse-grained, rigid-rod model that includes steric interactions and an internal dipole is used to study monolayers of surfactant molecules tethered to a flat interface. Monte Carlo simulations are performed in the canonical ensemble for a range of high-density configurations with varying degrees of dipole strength. Both a melting transition and a tilting transition are observed, and the dependence of the transitions on the surfactant molecules' internal dipoles is examined. Simulation results indicate that at high packing densities, the monolayers exist in a frustrated state due to dipole-dipole repulsions and steric interactions. Tilting of the surfactant molecules increases the magnitude of the dipole-dipole attractions and lowers the overall system energy, but is limited by steric repulsions. In simulations with higher dipole strengths, the melting and tilting transitions are found to be coupled. The formation of nanodomains with increased collective tilt and positional order in these systems suggests a possible mechanism for the coupling.
| Original language | English |
|---|---|
| Article number | 014703 |
| Journal | Journal of Chemical Physics |
| Volume | 132 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 2010 |
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ASJC Scopus subject areas
- Physics and Astronomy(all)
- Physical and Theoretical Chemistry
- Medicine(all)
Cite this
Langmuir monolayers with internal dipoles : Understanding phase behavior using Monte Carlo simulations. / George, Christopher B.; Ratner, Mark A; Szleifer, Igal.
In: Journal of Chemical Physics, Vol. 132, No. 1, 014703, 2010.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Langmuir monolayers with internal dipoles
T2 - Understanding phase behavior using Monte Carlo simulations
AU - George, Christopher B.
AU - Ratner, Mark A
AU - Szleifer, Igal
PY - 2010
Y1 - 2010
N2 - A coarse-grained, rigid-rod model that includes steric interactions and an internal dipole is used to study monolayers of surfactant molecules tethered to a flat interface. Monte Carlo simulations are performed in the canonical ensemble for a range of high-density configurations with varying degrees of dipole strength. Both a melting transition and a tilting transition are observed, and the dependence of the transitions on the surfactant molecules' internal dipoles is examined. Simulation results indicate that at high packing densities, the monolayers exist in a frustrated state due to dipole-dipole repulsions and steric interactions. Tilting of the surfactant molecules increases the magnitude of the dipole-dipole attractions and lowers the overall system energy, but is limited by steric repulsions. In simulations with higher dipole strengths, the melting and tilting transitions are found to be coupled. The formation of nanodomains with increased collective tilt and positional order in these systems suggests a possible mechanism for the coupling.
AB - A coarse-grained, rigid-rod model that includes steric interactions and an internal dipole is used to study monolayers of surfactant molecules tethered to a flat interface. Monte Carlo simulations are performed in the canonical ensemble for a range of high-density configurations with varying degrees of dipole strength. Both a melting transition and a tilting transition are observed, and the dependence of the transitions on the surfactant molecules' internal dipoles is examined. Simulation results indicate that at high packing densities, the monolayers exist in a frustrated state due to dipole-dipole repulsions and steric interactions. Tilting of the surfactant molecules increases the magnitude of the dipole-dipole attractions and lowers the overall system energy, but is limited by steric repulsions. In simulations with higher dipole strengths, the melting and tilting transitions are found to be coupled. The formation of nanodomains with increased collective tilt and positional order in these systems suggests a possible mechanism for the coupling.
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U2 - 10.1063/1.3280389
DO - 10.1063/1.3280389
M3 - Article
VL - 132
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
SN - 0021-9606
IS - 1
M1 - 014703
ER -