Journal of Chemical Physics
Feedback | Help | Exit
The Journal of Chemical Physics
   
 
 
 
Previous Article
Nuclear magnetic and quadrupole resonance study of molecular dynamics in a model bilayer compound C6H13NH3Cl
Molecular dynamics in a model bilayer compound C6H13NH3Cl is studied by 1H spin–lattice relaxation in the laboratory and in the dipolar system as well as by 14N nuclear quadrupole resonance. In t...
Next Article
Pump-probe spectroscopy of H-bonds as the level-crossing problem
Saturation of the H-bond absorption spectra by a strong laser field is described as a level-crossing problem with diffusional motion along the reaction coordinate. The stationary populations of the gr...

Effects of polydispersity on hard sphere crystals

J. Chem. Phys. 108, 9789 (1998); doi:10.1063/1.476453

Issue Date: 15 June 1998

You are not logged in to this journal. Log in

See-Eng Phan and William B. Russel
Department of Chemical Engineering, Princeton University, Princeton, New Jersey 08544

Jixiang Zhu and Paul M. Chaikin
Department of Physics, Princeton University, Princeton, New Jersey 08544
We use simple models and molecular dynamics simulations to determine the effects of polydispersity delta on the equation of state for hard sphere crystals. Experiments show that the osmotic pressure for poly-(methyl methacrylate) (PMMA) spheres with a poly-(12-hydroxy stearic acid) (PHSA) layer with a 5% polydispersity exceeds the value expected for hard spheres as the volume fraction phi increases, particularly for phi > 0.60. Mean field theory predicts a higher osmotic pressure with increasing polydispersity, but the effects are only significant for delta > 0.10. Molecular dynamics simulations with delta = 0.05 bound the equation of state between a metastable disordered upper limit and a crystalline organized polydisperse (possibly) lower limit. The pressure for the PMMA-PHSA spheres lies close to the organized polydisperse limit, indicating a preference for a crystalline ordered arrangement where smaller particles surround larger ones. Thus, the higher osmotic pressure seen in the equation of state of PMMA-PHSA spheres is a direct effect of polydispersity, manifest as a pronounced reduction in the crystalline close packed volume fraction from phimax(FCC, delta = 0)=0.7404 to phimax(FCC, delta = 0.1)=0.665. The random close packing phimax(RCP) is almost independent of polydispersity. This leads to a crossing of values of phimax(FCC) and phimax(RCP) and hence a possible terminal polydispersity of 0.12 ± 0.01, consistent with other simulations, theories, and experiments. Since our results do not include size fractionation of the liquid and solid, the exact meaning of this crossing is unclear and its agreement with previously reported terminal polydispersities may be coincidental. ©1998 American Institute of Physics.
History: Received 15 December 1997; accepted 13 March 1998
Permalink: http://link.aip.org/link/?JCPSA6/108/9789/1
BUY THIS ARTICLE   (US$28)
Download PDF (161 kB) View Cart

KEYWORDS and PACS

Keywords
PACS
  • 61.20.Ja
    Structure of solids and liquids; crystallography Structure of liquids Computer simulation of liquid structure
  • 02.70.Ns
    Mathematical methods in physics Computational techniques Molecular dynamics and particle methods
  • 05.20.-y
    Statistical physics and thermodynamics Statistical mechanics
  • 82.70.-y
    Physical chemistry Disperse systems
  • 83.80.Bp
    Rheology Material types Thermoplastic polymers
  • YEAR: 1998

PUBLICATION DATA

ISSN:
0021-9606 (print)   1089-7690 (online)
Publisher:
AIP is a member of CrossRef AIP

REFERENCES (27)
View in Separate Window/Tab
For access to fully linked references, you need to log in. For access to fully linked references, you need to Log in.
  1. J. Mewis, W. Frith, T. Strivens, and W. Russel, AIChE J. 35, 415 (1989).
  2. J. van der Werff and C. de Kruif, J. Rheol. 33, 421 (1989).
  3. C. de Kruif, E. van Iersel, A. Vrij, and W. Russel, J. Chem. Phys. 83, 4717 (1985).
  4. P. Pusey and W. van Megen, in An Exxon Monograph: Physics of Complex and Supermolecular Fluids, edited by S. A. Safran and N. A. Clark (Wiley, New York, 1987), pp. 673–698.
  5. P. Segrè, S. Meeker, P. Pusey, and W. Poon, Phys. Rev. Lett. 75, 958 (1995).
  6. S. Paulin and B. J. Ackerson, Phys. Rev. Lett. 64, 2663 (1990).
  7. S. Phan, W. B. Russel, Z. Cheng, J. Zhu, P. M. Chaikin, J. H. Dunsmuir, and R. H. Ottewill, Phys. Rev. E 54, 6633 (1996).
  8. P. Bolhuis and D. Kofke, Phys. Rev. E 54, 634 (1996).
  9. E. Dickinson, Chem. Phys. Lett. 57, 148 (1978).
  10. E. Dickinson, R. Parker, and M. Lal, Chem. Phys. Lett. 79, 578 (1981).
  11. I. Moriguchi, K. Kawasaki, and T. Kawakatsu, J. Phys. II (France) 3, 1179 (1993).
  12. E. Dickinson and R. Parker, J. Phys. Lett. 46, L229 (1985).
  13. R. McRae and A. Haymet, J. Chem. Phys. 88, 1114 (1988).
  14. J. Barrat and J. Hansen, J. Phys. (France) 47, 1547 (1986).
  15. N. Ito, Int. J. Mod. Phys. C 7, 275 (1996).
  16. P. Pusey, J. Phys. (France) 48, 709 (1987).
  17. S. Underwood, J. Taylor, and W. van Megen, Langmuir 10, 3550 (1994).
  18. K. Hall, J. Chem. Phys. 57, 2252 (1972).
  19. M. Allen and D. Tildesley, Computer Simulation of Liquids (Clarendon, Oxford, 1987).
  20. J. Haile, Molecular Dynamics Simulation (Wiley, New York, 1992).
  21. M. Rintoul and S. Torquato, J. Chem. Phys. 105, 9258 (1996).
  22. P. Steinhardt, D. Nelson, and M. Ronchetti, Phys. Rev. B 28, 784 (1983).
  23. J. van Duijneveldt and D. Frenkel, J. Chem. Phys. 96, 4655 (1992).
  24. H. Löwen, T. Palberg, and R. Simon, Phys. Rev. Lett. 70, 1557 (1993).
  25. J. Bongers and H. Versmold, J. Chem. Phys. 104, 1519 (1996).
  26. W. Schaertl and H. Sillescu, J. Stat. Phys. 77, 1007 (1994).
  27. P. Bolhuis and D. Kofke (private communication).

CITING ARTICLES
For access to citing articles, you need to log in.
For access to citing articles, you need to Log in.


Copyright © American Institute of Physics