TY - JOUR
T1 - Structure of solvent-free grafted nanoparticles
T2 - Molecular dynamics and density-functional theory
AU - Chremos, Alexandros
AU - Panagiotopoulos, Athanassios Z.
AU - Yu, Hsiu Yu
AU - Koch, Donald L.
N1 - Funding Information:
The authors would like to thank Professor Fernando Escobedo for suggesting the simulation model used in this work and for helpful discussions. This publication is based on work supported in part by Award No. KUS-C1-018-02, made by King Abdullah University of Science and Technology (KAUST). Additional support was provided by Grant No. DE-SC-0002128 from the (U.S.) Department of Energy (DOE), Office of Basic Energy Sciences and Grant No. CBET-1033155 from National Science Foundation (NSF).
PY - 2011/9/21
Y1 - 2011/9/21
N2 - The structure of solvent-free oligomer-grafted nanoparticles has been investigated using molecular dynamics simulations and density-functional theory. At low temperatures and moderate to high oligomer lengths, the qualitative features of the core particle pair probability, structure factor, and the oligomer brush configuration obtained from the simulations can be explained by a density-functional theory that incorporates the configurational entropy of the space-filling oligomers. In particular, the structure factor at small wave numbers attains a value much smaller than the corresponding hard-sphere suspension, the first peak of the pair distribution function is enhanced due to entropic attractions among the particles, and the oligomer brush expands with decreasing particle volume fraction to fill the interstitial space. At higher temperatures, the simulations reveal effects that differ from the theory and are likely caused by steric repulsions of the expanded corona chains.
AB - The structure of solvent-free oligomer-grafted nanoparticles has been investigated using molecular dynamics simulations and density-functional theory. At low temperatures and moderate to high oligomer lengths, the qualitative features of the core particle pair probability, structure factor, and the oligomer brush configuration obtained from the simulations can be explained by a density-functional theory that incorporates the configurational entropy of the space-filling oligomers. In particular, the structure factor at small wave numbers attains a value much smaller than the corresponding hard-sphere suspension, the first peak of the pair distribution function is enhanced due to entropic attractions among the particles, and the oligomer brush expands with decreasing particle volume fraction to fill the interstitial space. At higher temperatures, the simulations reveal effects that differ from the theory and are likely caused by steric repulsions of the expanded corona chains.
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U2 - 10.1063/1.3638179
DO - 10.1063/1.3638179
M3 - Article
C2 - 21950881
AN - SCOPUS:80053199771
SN - 0021-9606
VL - 135
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 11
M1 - 114901
ER -