TY - JOUR
T1 - Structure and assembly of dense solutions and melts of single tethered nanoparticles
AU - Jayaraman, Arthi
AU - Schweizer, Kenneth S.
N1 - Funding Information:
This work was supported by the Nanoscale Science and Engineering Initiative of the National Science foundation under NSF Award No. DMR-0642573. We thank Chris Iacovella and Sharon Glotzer for discussions of their simulation results.
PY - 2008
Y1 - 2008
N2 - The microscopic polymer reference interaction site model theory is generalized and applied to study intermolecular pair correlation functions and collective structure factors of dense solutions and melts of spherical nanoparticles carrying a single tethered chain. The complex interplay of entropy (translational, conformational, and packing) and enthalpy (particle-particle attraction) leads to different structural arrangements with distinctive small and wide angle scattering signatures. Strong concentration fluctuations, indicative of aggregate formation and/or a tendency for microphase separation, occur as the total packing fraction and/or particle-particle attraction strength increase. In analogy with block copolymers, the microphase spinodal curve is estimated by extrapolation of the inverse of the amplitude of the small angle scattering peak. For nanoparticles that are twice the diameter of monomers, the microphase separation boundary spinodal occurs at higher particle-particle attraction strength (or lower temperature) as compared to the macrophase demixing curve for nanoparticles with no tethers when the packing fraction is below 0.45, while the opposite trend is observed above 0.45. Increasing nanoparticle diameter results in a reduction in the microphase spinodal temperature and a qualitative change in its packing fraction dependence.
AB - The microscopic polymer reference interaction site model theory is generalized and applied to study intermolecular pair correlation functions and collective structure factors of dense solutions and melts of spherical nanoparticles carrying a single tethered chain. The complex interplay of entropy (translational, conformational, and packing) and enthalpy (particle-particle attraction) leads to different structural arrangements with distinctive small and wide angle scattering signatures. Strong concentration fluctuations, indicative of aggregate formation and/or a tendency for microphase separation, occur as the total packing fraction and/or particle-particle attraction strength increase. In analogy with block copolymers, the microphase spinodal curve is estimated by extrapolation of the inverse of the amplitude of the small angle scattering peak. For nanoparticles that are twice the diameter of monomers, the microphase separation boundary spinodal occurs at higher particle-particle attraction strength (or lower temperature) as compared to the macrophase demixing curve for nanoparticles with no tethers when the packing fraction is below 0.45, while the opposite trend is observed above 0.45. Increasing nanoparticle diameter results in a reduction in the microphase spinodal temperature and a qualitative change in its packing fraction dependence.
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U2 - 10.1063/1.2907717
DO - 10.1063/1.2907717
M3 - Article
C2 - 18447497
AN - SCOPUS:42949103106
SN - 0021-9606
VL - 128
JO - Journal of Chemical Physics
JF - Journal of Chemical Physics
IS - 16
M1 - 164904
ER -