TY - JOUR
T1 - Differences in free surfactant concentration and aggregation properties for amphiphiles with the same critical micelle concentration
AU - Jiao, Sally
AU - Santos, Andrew P.
AU - Panagiotopoulos, Athanassios Z.
N1 - Funding Information:
Financial support for this work was provided by the Department of Energy, Office of Basic Energy Sciences , under award DE- SC0002128 . In addition, A. P. S. acknowledges financial support from the National Science Foundation Graduate Research Fellowship under Grant No. DGE-1656466 . Computing resources were provided by the Princeton Institute for Computational Science and Engineering (PICSciE).
Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2018/8/25
Y1 - 2018/8/25
N2 - The impact of surfactant architecture on aggregation behavior is investigated using grand canonical Monte Carlo simulations of a lattice surfactant model. Many prior studies have observed differences in macroscopic surfactant system properties or in aggregation behavior for diblock surfactant architectures with varying head length, tail length, and head-to-tail ratio. However, the critical micelle concentration (cmc) also varies with these parameters, thus complicating the comparisons. In the present study, we separate the effects of varying cmc and varying architecture by comparing properties of amphiphiles with the same cmc using a simple lattice nonionic surfactant model in implicit solvent. We find that architectural variables such as the head length and the head-to-tail ratio do have a significant effect on structural micellar properties. We also identify differences in free surfactant concentrations, even when calculated in the volume accessible to them in solution. We modify a previously proposed correction to the free surfactant concentration in order to obtain the cmc from simulations at high concentrations. The differences in aggregation behavior reported using this model can be extended to differences in observed macroscopic properties for real surfactant systems.
AB - The impact of surfactant architecture on aggregation behavior is investigated using grand canonical Monte Carlo simulations of a lattice surfactant model. Many prior studies have observed differences in macroscopic surfactant system properties or in aggregation behavior for diblock surfactant architectures with varying head length, tail length, and head-to-tail ratio. However, the critical micelle concentration (cmc) also varies with these parameters, thus complicating the comparisons. In the present study, we separate the effects of varying cmc and varying architecture by comparing properties of amphiphiles with the same cmc using a simple lattice nonionic surfactant model in implicit solvent. We find that architectural variables such as the head length and the head-to-tail ratio do have a significant effect on structural micellar properties. We also identify differences in free surfactant concentrations, even when calculated in the volume accessible to them in solution. We modify a previously proposed correction to the free surfactant concentration in order to obtain the cmc from simulations at high concentrations. The differences in aggregation behavior reported using this model can be extended to differences in observed macroscopic properties for real surfactant systems.
KW - Block copolymers
KW - Micellization
KW - Self-assembly
KW - Surfactants
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U2 - 10.1016/j.fluid.2017.10.026
DO - 10.1016/j.fluid.2017.10.026
M3 - Article
AN - SCOPUS:85034589156
SN - 0378-3812
VL - 470
SP - 126
EP - 133
JO - Fluid Phase Equilibria
JF - Fluid Phase Equilibria
ER -